John Deere stx38 User Manual

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STX30, STX38, and STX46

Lawn Tractors

TECHNICAL

MANUAL

John Deere

Worldwide Commercial and

Consumer Equipment Division

TM1561 (15Mar97)

Replaces TM1561 (01Sep95) and

TM1418 (26Oct92)

Litho in U.S.A

M55912

M55913

STX38 Gear Drive

STX38 Motorsport Edition

STX38 Hydrostatic Drive

M85680

M58332

M58333M58333

STX46 Hydrostatic DriveSTX46 Gear Drive

This technical manual is written for an experienced technician and contains sections that are specifically for this product. It is a part of a total product support program.

INTRODUCTION

Safety

Specifications and Information

The manual is organized so that all the information on a particular system is kept together. The order of grouping is as follows:

• Table of Contents

• Specifications

• Theory of Operation

• Troubleshooting Diagram

• Diagnostics

• Tests & Adjustments

• Repair Note: Depending on the particular section or system

being covered, not all of the above groups may be used.

Each section will be identified with a symbol rather than a number. The groups and pages within a section will be consecutively numbered.

Engine

Electrical

Power Train

(Gear)

Power Train

(Hydrostatic)

Steering

All information, illustrations and specifications in this manual are based on the latest information available at the time of publication. The right is reserved to make changes at any time without notice.

We appreciate your input on this manual. To help, there are postage paid post cards included at the back. If you find any errors or want to comment on the layout of the manual please fill out one of the cards and mail it back to us.

JOHN DEERE HORICON WORKS

Horicon, Wisconsin

1997

Miscellaneous

3/12/97

1 - 1

SAFETY

RECOGNIZE SAFETY INFORMATION

This is the safety-alert symbol. When you see this symbol on your machine or in this manual, be alert to the potential for personal injury.

Follow recommended precautions and safe servicing practices.

Understand Signal Words

HANDLE FLUIDS SAFELY-AVOID FIRES

Be Prepared For Emergencies

A signal word—DANGER, WARNING, or CAUTION— is used with the safety-alert symbol. DANGER identifies the most serious hazards.

DANGER or WARNING safety signs are located near specific hazards. General precautions are listed on CAUTION safety signs. CAUTION also calls attention to safety messages in this manual.

REPLACE SAFETY SIGNS

When you work around fuel, do not smoke or work near heaters or other fire hazards.

Store flammable fluids away from fire hazards. Do not incinerate or puncture pressurized containers.

Make sure machine is clean of trash, grease, and debris.

Do not store oily rags; they can ignite and burn spontaneously.

Be prepared if a fire starts. Keep a first aid kit and fire extinguisher handy. Keep emergency numbers for doctors, ambulance

service, hospital, and fire department near your telephone.

Replace missing or damaged safety signs. See the machine operator’s manual for correct safety sign placement.

1 - 2

3/12/97

SAFETY

USE CARE IN HANDLING AND SERVICING BATTERIES

Prevent Battery Explosions

• Keep sparks, lighted matches, and open flame away from the top of battery. Battery gas can explode.

• Never check battery charge by placing a metal object across the posts. Use a volt-meter or hydrometer.

• Do not charge a frozen battery; it may explode. Warm battery to 16°C (60°F).

Prevent Acid Burns

• Sulfuric acid in battery electrolyte is poisonous. It is strong enough to burn skin, eat holes in clothing, and cause blindness if splashed into eyes.

• Avoid acid burns by:

1. Filling batteries in a well-ventilated area.

2. Wearing eye protection and rubber gloves.

3. Avoiding breathing fumes when electrolyte is added.

4. Avoiding spilling or dripping electrolyte.

5. Use proper jump start procedure.

USE CARE AROUND HIGHPRESSURE FLUID LINES

Avoid High-pressure Fluids

Escaping fluid under pressure can penetrate the skin causing serious injury.

Avoid injury from escaping fluid under pressure by stopping the engine and relieving pressure in the system before disconnecting or connecting hydraulic or other lines. Tighten all connections before applying pressure.

Search for leaks with a piece of cardboard. Protect hands and body from high pressure fluids.

If an accident occurs, see a doctor immediately. Any fluid injected into the skin must be surgically removed within a few hours or gangrene may result. Doctors unfamiliar with this type of injury should reference a knowledgeable medical source. Such information is available from Deere & Company Medical Department in Moline, Illinois, U.S.A.

Avoid Heating Near Pressurized Fluid Lines

• If you spill acid on yourself:

1. Flush your skin with water.

2. Apply baking soda or lime to help neutralize the acid.

3. Flush your eyes with water for 10_15 minutes.

4. Get medical attention immediately.

• If acid is swallowed:

1. Drink large amounts of water or milk.

2. Then drink milk of magnesia, beaten eggs, or vegetable oil.

3. Get medical attention immediately.

3/12/97

Flammable spray can be generated by heating near pressurized fluid lines, resulting in severe burns to yourself and bystanders. Do not heat by welding, soldering, or using a torch near pressurized fluid lines or other flammable materials. Pressurized lines can be accidentally cut when heat goes beyond the immediate flame area.

1 - 3

SAFETY

USE SAFE SERVICE PROCEDURES Wear Protective Clothing

Wear close fitting clothing and safety equipment appropriate to the job.

Prolonged exposure to loud noise can cause impairment or loss of hearing. Wear a suitable hearing protective device such as earmuffs or earplugs to protect against objectionable or uncomfortable loud noises.

Operating equipment safely requires the full attention of the operator. Do not wear radio or music headphones while operating machine.

Park Machine Safely

Before working on the machine:

1. Lower all equipment to the ground.

2. Stop the engine and remove the key.

3. Disconnect the battery ground strap.

4. Hang a “DO NOT OPERATE” tag in operator station.

Support Machine Properly And Use Proper Lifting Equipment

Service Machines Safely

Tie long hair behind your head. Do not wear a necktie, scarf, loose clothing, or necklace when you work near machine tools or moving parts. If these items were to get caught, severe injury could result.

Remove rings and other jewelry to prevent electrical shorts and entanglement in moving parts.

Use Proper Tools

Use tools appropriate to the work. Makeshift tools and procedures can create safety hazards. Use power tools only to loosen threaded parts and fasteners. For loosening and tightening hardware, use the correct size tools. metric fasteners. Avoid bodily injury caused by slipping wrenches. Use only service parts meeting John Deere specifications.

DO NOT

use U.S. measurement tools on

If you must work on a lifted machine or attachment, securely support the machine or attachment.

Do not support the machine on cinder blocks, hollow tiles, or props that may crumble under continuous load. Do not work under a machine that is supported solely by a jack. Follow recommended procedures in this manual.

Lifting heavy components incorrectly can cause severe injury or machine damage. Follow recommended procedure for removal and installation of components in the manual.

Work In Clean Area

Before starting a job:

1. Clean work area and machine.

2. Make sure you have all necessary tools to do your job.

3. Have the right parts on hand.

4. Read all instructions thoroughly; do not attempt shortcuts.

1 - 4

3/12/97

SAFETY

Using High Pressure Washers

Directing pressurized water at electronic/electrical components or connectors, bearings, hydraulic seals, fuel injection pumps or other sensitive parts and components may cause product malfunctions. Reduce pressure and spray at a 45 to 90 degree angle.

Illuminate Work Area Safely

Illuminate your work area adequately but safely. Use a portable safety light for working inside or under the machine. Make sure the bulb is enclosed by a wire cage. The hot filament of an accidentally broken bulb can ignite spilled fuel or oil.

Work In Ventilated Area

Avoid Harmful Asbestos Dust

Avoid breathing dust that may be generated when handling components containing asbestos fibers. Inhaled asbestos fibers may cause lung cancer.

Components in products that may contain asbestos fibers are brake pads, brake band and lining assemblies, clutch plates, and some gaskets. The asbestos used in these components is usually found in a resin or sealed in some way. Normal handling is not hazardous as long as airborne dust containing asbestos is not generated.

Avoid creating dust. Never use compressed air for cleaning. Avoid brushing or grinding material containing asbestos. When servicing, wear an approved respirator. A special vacuum cleaner is recommended to clean asbestos. If not available, apply a mist of oil or water on the material containing asbestos. Keep bystanders away from the area.

SERVICE TIRES SAFELY

Engine exhaust fumes can cause sickness or death. If it is necessary to run an engine in an enclosed area, remove the exhaust fumes from the area with an exhaust pipe extension.

If you do not have an exhaust pipe extension, open the doors and get outside air into the area.

WARNING: California Proposition 65 Warning

Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.

Gasoline engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.

Remove Paint Before Welding Or Heating

Avoid potentially toxic fumes and dust. Hazardous fumes can be generated when paint is heated by welding, soldering, or using a torch. Do all work outside or in a well ventilated area. Dispose of paint and solvent properly. Remove paint before welding or heating: If you sand or grind paint, avoid breathing the dust. Wear an approved respirator. If you use solvent or paint stripper, remove stripper with soap and water before welding. Remove solvent or paint stripper containers and other flammable material from area. Allow fumes to disperse at least 15 minutes before welding or heating.

Explosive separation of a tire and rim parts can cause serious injury or death.

Do not attempt to mount a tire unless you have the proper equipment and experience to perform the job. Always maintain the correct tire pressure. Do not inflate the tires above the recommended pressure. Never weld or heat a wheel and tire assembly. The heat can cause an increase in air pressure resulting in a tire explosion. Welding can structurally weaken or deform the wheel.

When inflating tires, use a clip-on chuck and extension hose long enough to allow you to stand to one side and NOT in front of or over the tire assembly. Use a safety cage if available.

Check wheels for low pressure, cuts, bubbles, damaged rims or missing lug bolts and nuts.

3/12/97

1 - 5

SAFETY

AVOID INJURY FROM ROTATING BLADES, AUGERS AND PTO SHAFTS

Keep hands and feet away while machine is running. Shut off power to service, lubricate or remove mower blades, augers or PTO shafts.

SERVICE COOLING SYSTEM SAFELY

Direct exposure to hazardous chemicals can cause serious injury. Potentially hazardous chemicals used with John Deere equipment include such items as lubricants, coolants, paints, and adhesives.

A Material Safety Data Sheet (MSDS) provides specific details on chemical products: physical and health hazards, safety procedures, and emergency response techniques. Check the MSDS before you start any job using a hazardous chemical. That way you will know exactly what the risks are and how to do the job safely. Then follow procedures and recommended equipment.

Dispose of Waste Properly

Explosive release of fluids from pressurized cooling system can cause serious burns.

Shut off machine. Only remove filler cap when cool enough to touch with bare hands. Slowly loosen cap to first stop to relieve pressure before removing completely.

HANDLE CHEMICAL PRODUCTS SAFELY

Improperly disposing of waste can threaten the environment and ecology. Potentially harmful waste used with John Deere equipment include such items as oil, fuel, coolant, brake fluid, filters, and batteries. Use leakproof containers when draining fluids. Do not use food or beverage containers that may mislead someone into drinking from them. Do not pour waste onto the ground, down a drain, or into any water source. Inquire on the proper way to recycle or dispose of waste from your local environmental or recycling center, or from your John Deere dealer.

LIVE WITH SAFETY

1 - 6

Before returning machine to customer, make sure machine is functioning properly, especially the safety systems. Install all guards and shields.

3/12/97

SPECIFICATIONS & INFORMATION

GENERAL VEHICLE SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 3

METRIC FASTENER TORQUE VALUES. . . . . . . . . . . . . . . . . . . . . . . . . 6

METRIC FASTENER TORQUE VALUE - GRADE 7. . . . . . . . . . . . . . . . . . . . . . . . . . 7

INCH FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

O-RING SEAL SERVICE RECOMMENDATIONS . . . . . . . . . . . . . . . . . . 9

FACE SEAL FITTINGS WITH INCH STUD ENDS TORQUE . . . . . . . . . . . . . . . . . . . 9

FACE SEAL FITTINGS WITH METRIC STUD ENDS TORQUE . . . . . . . . . . . . . . . 10

O-RING FACE SEAL FITTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

O-RING BOSS FITTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

GASOLINE SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4–CYCLE ENGINES - NORTH AMERICA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

GASOLINE STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4–CYCLE ENGINES - EUROPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

GASOLINE STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4–CYCLE GASOLINE ENGINE OIL. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4–CYCLE GASOLINE ENGINE OIL - NORTH AMERICA . . . . . . . . . . . . . . . . . . . . 14

4–CYCLE GASOLINE ENGINE OIL - EUROPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

BREAK–IN 4-CYCLE GASOLINE ENGINE OIL - NORTH AMERICA . . . . . . . . . . . 16

BREAK–IN 4-CYCLE GASOLINE ENGINE OIL - EUROPE . . . . . . . . . . . . . . . . . . . 17

HYDROSTATIC TRANSMISSION OIL. . . . . . . . . . . . . . . . . . . . . . . . . . 18

HYDROSTATIC TRANSMISSION OIL - NORTH AMERICA . . . . . . . . . . . . . . . . . . 18

HYDROSTATIC TRANSMISSION OIL - EUROPE . . . . . . . . . . . . . . . . . . . . . . . . . . 19

ALTERNATIVE LUBRICANTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

SYNTHETIC LUBRICANTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

LUBRICANT STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

MIXING OF LUBRICANTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

OIL FILTERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

GEAR TRANSMISSION GREASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

ANTI-CORROSION GREASE SPECIFICATIONS . . . . . . . . . . . . . . . . . 22

GREASE SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

GREASE - NORTH AMERICA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

GREASE - EUROPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

SERIAL NUMBER LOCATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

ENGINE SERIAL NUMBER SUFFUX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

TRACTOR IDENTIFICATION NUMBER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

ENGINE SERIAL NUMBER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

GEAR TRANSAXLE SERIAL NUMBER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

HYDROSTATIC TRANSMISSION SERIAL NUMBER . . . . . . . . . . . . . . . . . . . . . . . 24

CONTENTS

Page

SPECIFICATIONS & INFORMATION

3/12/97

2 - 1

NOTES

SPECIFICATIONS & INFORMATION

2 - 2

3/12/97

SPECIFICATIONS AND INFORMATION

GENERAL VEHICLE SPECIFICATIONS

Engine:

Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kohler

Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Command LT

STX30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CV12.5—1216s

STX38 (Serial No. —270000) . . . . . . . . . . . . . . . . . . . . . . . . . . . .CV12.5—1215

STX38 (Serial No. 210001—270000) . . . . . . . . . . . . . . . . . . . . . . . . . . . .CV12.5—1270

STX38 (Serial No. 270001—595000 & Motorsport) . . . . . . . . . . . . . . . . CV13S—21509

STX46 (Serial No. 210001—270000) . . . . . . . . . . . . . . . . . . . . . . . . . . . . CV14S—1463

STX46 (Serial No. 270001—595000) . . . . . . . . . . . . . . . . . . . . . . . . . . . CV15S—41521

Type . . . . . . . . . . . . . Gasoline, Air Cooled, Single Cylinder, 4-Cycle, Overhead Valves

Crankcase Oil Capacity (with filter). . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 L (1.9 U.S. qt)

Oil Type: (Warm Climate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10W30

(Cold Climate). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5W30

Electrical:

Charging System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flywheel/Electronic Magneto

Magneto Air Gap. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2—0.3 mm (0.008—0.012 in.)

Charging Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 amp (regulated)

Spark Plug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Champion RC12YC

Spark Plug Air Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 mm (0.040 in.)

Battery Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .BCI Group, U1

Battery Reserve Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 min. at 25 amp

Battery Cold Cranking Amp. . . . . . . . . . . . . . . . . .25 amp at 27° C (0° F) for 20 minutes

Battery Specific Gravity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Above 1.225 Points

Starter Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bendix Inertia Drive

PTO Clutch Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . Electric (Manufactured by Warner)

Fuel Shut-Off Solenoid (Optional). . . . . . . . Replaceable (Below Carburetor Float Bowl)

Headlight Kit (Optional). . . . . . . . . . . . . . Two Bulbs—Each 12 Volt/23W/1.9 Amp Draw

Fuel/Air System:

Carburetor Make. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Walbro

Carburetor Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Side Draft

Throttle/Choke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unitized Control Linkage

Carburetor Fuel Shut-Off Solenoid (Optional). . . . . . . . . . . . . . . . . . . . . . . . . . . .Electric

Fuel Delivery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gravity Flow

Fuel Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Replaceable Paper (in-line type)

Fuel Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unleaded (87 octane minimum)

Fuel Tank Capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 L (1.25 gal)

Air Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paper Element with Foam Pre-cleaner

Muffler Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anti-Backfire

Power Train:

Gear Transaxle—

Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dana

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Spicer Heavy-Duty 4360 Transaxle

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Five-Speed/Linear Shift

Domestic Ground Speeds (at FAST idle—3350 rpm) and Gear Ratios:

1st Gear . (STX30 & STX38 SN —210000 2.2km/hr) 2.4 km/hr (1.5 mph)—61.67:1

2nd Gear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 km/hr (2.0 mph)—46.67:1

3rd Gear . (STX30 & STX38 SN —210000 4.5km/hr) 5.0 km/hr (3.1 mph)—30.00:1 4th Gear . (STX30 & STX38 SN —210000 5.7km/hr) 6.4 km/hr (4.0 mph)—23.48:1 5th Gear . (STX30 & STX38 SN —210000 8.5km/hr) 8.0 km/hr (5.0 mph)—15.71:1 Reverse . .(STX30 & STX38 SN —210000 3.3km/hr) 3.7 km/hr (2.3 mph)—40.00:1

Export Ground Speeds (at FAST idle—3000 rpm) and Gear Ratios:

1st Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.97 km/hr (1.22 mph)—61.67:1

2nd Gear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.61 km/hr (1.67 mph)—46.67:1

3rd Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.07 km/hr (2.53 mph)—30.00:1

4th Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.18 km/hr (3.22 mph)—23.48:1

5th Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.76 km/hr (4.82 mph)—15.71:1

Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.04 km/hr (1.89 mph)—40.00:1

Brake Type . . . . . . . . . . . . . . . . . .Single, External Brake Disc With Dual Friction Pucks

GENERAL VEHICLE SPECIFICATIONS

3/20/97

2 - 3

GENERAL VEHICLE SPECIFICATIONS

Power Train: (Continued)

Lubrication—Input Shaft Needle Bearings . . . . . . . . . . . . . . . .Unirex® N3 Grease Only

Lubrication—Transaxle. . . . . . . . . . . . . . . . . . . . . . . . . . . Shell Darina® D Grease Only

Capacity—Transaxle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.64 kg (1.406 lbs)

Hydro Transaxle—

Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kanzaki

Model (STX38—early models) . . . . . . . . . . . . . . . . . . . . . . . .Tuff Torq® K50 Transaxle

Model (STX38—late models) . . . . . . . . . . . . . . . . . . . . . . . . .Tuff Torq® K55 Transaxle

Model (STX46) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tuff Torq® K55 Transaxle

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydrostatic

Domestic Ground Speeds (at FAST idle—3350 rpm):

Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0—9.3 km/hr (0—5.8 mph)

Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0—4.7 km/hr (0—2.9 mph)

Export Ground Speeds (at FAST idle—3000 rpm):

Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0—7.75 km/hr (0—4.82 mph)

Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0—3.80 km/hr (0—2.36 mph)

Brake Type . . . . . . . . . . . . . . . . . . . . . .Single, External Disc Brake With Friction Pucks

Lubrication. . . . . . . . . . . . . . . . . . . . . . John Deere Plus-4 10W30 Engine Oil, Class CD

Reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Internal

Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 L (3.4 pt)

SPECIFICATIONS AND INFORMATION

Traction Drive Belt: Gear—

Actual effective length . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2660±8 mm (104.7±0.3 in.)

Theoretical effective length (short) . . . . . . . . . . . . . . . . . . . . . . . . . 2631 mm (103.6 in.)

Theoretical effective length (long). . . . . . . . . . . . . . . . . . . . . . . . . . 2710 mm (106.7 in.)

Hydro—

Actual effective length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2485±8 mm (97.8±0.3 in.)

Theoretical effective length (short) . . . . . . . . . . . . . . . . . . . . . . . . . . 2477 mm (97.5 in.)

Theoretical effective length (long). . . . . . . . . . . . . . . . . . . . . . . . . . . 2530 mm (99.6 in.)

Mower Deck Drive Belt 38-Inch Deck—

Actual effective length . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2425±10 mm (95.5±0.4 in.)

46-Inch Deck—

Actual effective length . . . . . . . . . . . . . . . . . . . . . . . . . . . .3492±10 mm (137.5±0.4 in.)

Mower Deck: 38-Inch Mower Deck—

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotary—Dual Spindles (Non-Serviceable)

Material Type . . . . . . . . . . . . . . . . . .Stamped 2.5 mm (0.098 in.) Nominal Gauge Steel

Cutting Blade. . . . . . . . . . . . . . . . . . . . . . . . . Two—76 x 5 x 496 mm (3 x 0.2 x 19.5 in.)

Blade Cutting Edge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30±5° Angle

Blade Wing Lift/Height. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40±3 mm (1.57±0.12 in.)

Overall Cutting Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 965 mm (38 in.)

Overall Width (w/o discharge chute). . . . . . . . . . . . . . . . . . . . . . . . . 1026 mm (40.4 in.)

Drive Type. . . . . . . . . . . . . . . . . . . . . . . . . . . Single V-Belt (with spring-tensioned idler)

Spindle Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . None—Sealed Bearings

Lift Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manual—Operator’s Station

Cutting Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . .Seven: 31.8—89 mm (1.25—3.5 in.)

2 - 4

3/20/97

SPECIFICATIONS AND INFORMATION

Mower Deck: (Continued) 46-Inch Mower Deck—

Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotary—Triple Spindles (Non-Serviceable)

Material Type . . . . . . . . . . . . . . . . . . Stamped 2.5 mm (0.098 in.) Nominal Gauge Steel

Cutting Blade . . . . . . . . . . . . . . . . . . . . . .Three—50.8 x 5 x 407.4 mm (2 x 0.2 x 16 in.)

Blade Cutting Edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30±5° Angle

Blade Wing Lift/Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20.3±3 mm (0.8±0.12 in.)

Overall Cutting Width. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1168.4 mm (46 in.)

Overall Width (w/o discharge chute) . . . . . . . . . . . . . . . . . . . . . . . . . 1308 mm (51.5 in.)

Drive Type . . . . . . . . . . . . . . . . . . . . . . . . . . . Single V-Belt (with spring-tensioned idler)

Spindle Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . None—Supplier Fill Only

Lift Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manual—Operator’s Station

Cutting Settings . . . . . . . . . . . . . . . . . . . . . . .Seven: 31.75 mm—89 mm (1.25—3.5 in.)

Chassis:

Wheelbase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1135 mm (44.69 in.)

Overall Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1524 mm (60 in.)

Overall Width (w/o mower deck) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 908 mm (35.75 in.)

Height. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .980 mm (38.6 in.)

Average Overall Weight STX38 (with mower deck/no fuel). . . . . . . .195.05 kg (430 lbs)

Average Overall Weight STX46 (with mower deck/no fuel). . . . . . . .204.12 kg (450 lbs)

Hitch Capacity—

Export:

Horizontal Pull Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .250 N (56 lbs)

Tongue Weight Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 N (15 lbs)

Domestic:

Trailer Load Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 kg (300 lbs)

Trailer Tongue Weight Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 kg (50 lbs)

GENERAL VEHICLE SPECIFICATIONS

Steering:

Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Manual—Pinion/Sector

Axle Pivot Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shim Adjustable

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DuBois MPG-2® Multipurpose Grease

Lubrication Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 hrs (maximum)

Toe-In. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 mm (0.24 in.) — Non-Adjustable

Turning Radius. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 584 mm (23 in.)

Wheels:

Size—

Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 x 4.50

Rear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 x 6.18

Tires:

Size—

Front (STX30) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 x 5—6 NHS (2 ply)

Rear (STX30) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 x 6.50—8 NHS (2 ply)

Front (STX38 SN —210000) . . . . . . . . . . . . . . . . . . . . . . . 13 x 6.50—6 NHS (2 ply)

Rear (STX38 SN —210000). . . . . . . . . . . . . . . . . . . . . . . . 18 x 8.50—8 NHS (2 ply)

Front (STX38 SN 210001—270000). . . . . . . . . . . . . . . . . . . 13 x 6.50—6 NHS (2 ply)

Rear (STX38 SN 210001—270000) . . . . . . . . . . . . . . . . . . . 18 x 9.50—8 NHS (2 ply)

Front (STX38 SN 270001—595000 & STX46) . . . . . . . . . . . 15 x 6.50—6 NHS (2 ply)

Rear (STX38 SN 270001—595000 & STX46) . . . . . . . . . . . 20 x 8.00—8 NHS (2 ply)

Pressure—

Front (with mower deck) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 kPa (12 psi)

Front (with snowthrower). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 kPa (20 psi)

Rear (STX30 with mower deck). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 kPa (14 psi)

Rear (with mower deck). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 kPa (8 psi)

3/20/97

2 - 5

METRIC FASTENER TORQUE VALUES

SPECIFICATIONS AND INFORMATION

4.8

8.8

9.8

10.9

12.9

Property Class and

4.8

8.8

9.8

10.9

12.9

Head Markings

Property

4.8

8.8

9.8

10.9

12.9

Class and Nut Markings

Class 4.8 Class 8.8 or 9.8 Class 10.9 Class 12.9

Lubricated SIZE N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft M6 M8 M10 M12

4.8 3.5 6 4.5 9 6.5 11 8.5 13 9.5 17 12 15 11.5 19 14.5

12 8.5 15 11 22 16 28 20 32 24 40 30 37 28 47 35

23 17 29 21 43 32 55 40 63 47 80 60 75 55 95 70

40 29 50 37 75 55 95 70 110 80 140 105 130 95 165 120

Dry

Lubricated

Dry

Lubricated

Dry

Lubricated

TS1163

Dry

M14 M16 M18 M20 M22 M24 M27 M30 M33 M36

63 47 80 60 120 88 150 110 175 130 225 165 205 150 260 109

100 73 125 92 190 140 240 175 275 200 350 225 320 240 400 300

135 100 175 125 260 195 330 250 375 275 475 350 440 325 560 410

190 140 240 180 375 275 475 350 530 400 675 500 625 460 800 580

260 190 330 250 510 375 650 475 725 540 925 675 850 625 1075 800

330 250 425 310 650 475 825 600 925 675 1150 850 1075 800 1350 1000

490 360 625 450 950 700 1200 875 1350 1000 1700 1250 1600 1150 2000 1500

675 490 850 625 1300 950 1650 1200 1850 1350 2300 1700 2150 1600 2700 2000

900 675 1150 850 1750 1300 2200 1650 2500 1850 3150 2350 2900 2150 3700 2750

1150 850 1450 1075 2250 1650 2850 2100 3200 2350 4050 3000 3750 2750 4750 3500

DO NOT use these hand torque values if a different torque value or tightening procedure is given for a specific application. Torque values listed are for general use only and include a ±10% variance factor. Check tightness of fasteners periodically. DO NOT use air powered wrenches.

Shear bolts are designed to fail under predetermined loads. Always replace shear bolts with identical grade.

Fasteners should be replaced with the same class. Make sure fastener threads are clean and that you properly start thread engagement. This will prevent them from failing when tightening.

When bolt and nut combination fasteners are used, torque values should be applied to the

NUT

instead of

the bolt head. Tighten toothed or serrated-type lock nuts to the full

torque value.

“Lubricated” means coated with a lubricant such as engine oil, or fasteners with phosphate and oil coatings. “Dry” means plain or zinc plated (yellow dichromate - Specification JDS117) without any lubrication

Reference: JDS—G200.

2 - 6

3/20/97

SPECIFICATIONS AND INFORMATION

METRIC FASTENER TORQUE VALUE - GRADE 7

METRIC FASTENER TORQUE VALUES

Steel or Gray

Size

M6 11 8 8 6

M8 24 18 19 14 M10 52 38 41 30 M12 88 65 70 52 M14 138 102 111 82 M16 224 165 179 132

Iron Torque

N•m lb-ft N•m lb-ft

Aluminum

Torque

3/20/97

2 - 7

INCH FASTENER TORQUE VALUES

SPECIFICATIONS AND INFORMATION

SAE

1 or 2

5.1

5.2

8.2

Grade and Head

No Marks

Markings

8 SAE Grade and Nut

No Marks

Markings

TS1162

Grade 1 Grade 2

Lubricated SIZE N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft N•m lb-ft 1/4 5/16 3/8 7/16 1/2

3.7 2.8 4.7 3.5 6 4.5 7.5 5.5 9.5 712913.5 10 17 12.5

7.7 5.5 10 7 12 9151120 15 25 18 28 21 35 26

14 10 17 13 22 16 27 20 35 26 44 33 50 36 63 46

22 16 28 20 35 26 44 32 55 41 70 52 80 58 100 75

33 25 42 31 53 39 67 50 85 63 110 80 120 90 150 115

Dry

Lubricated

Grade 5, 5.1 or 5.2 Grade 8 or 8.2

Dry

Lubricated

Dry

Lubricated

Dry

9/16 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2

48 36 60 45 75 56 95 70 125 90 155 115 175 130 225 160

67 50 85 62 105 78 135 100 170 125 215 160 215 160 300 225

120 87 150 110 190 140 240 175 300 225 375 280 425 310 550 400

190 140 240 175 190 140 240 175 490 360 625 450 700 500 875 650

290 210 360 270 290 210 360 270 725 540 925 675 1050 750 1300 975

470 300 510 375 470 300 510 375 900 675 1150 850 1450 1075 1850 1350

570 425 725 530 570 425 725 530 1300 950 1650 1200 2050 1500 2600 1950

750 550 950 700 750 550 950 700 1700 1250 2150 1550 2700 2000 3400 2550

1000 725 1250 925 990 725 1250 930 2250 1650 2850 2100 3600 2650 4550 3350

Shear bolts are designed to fail under predetermined loads. Always replace shear bolts with identical grade.

Fasteners should be replaced with the same grade. Make sure fastener threads are clean and that you properly start thread engagement. This will prevent them from failing when tightening.

When bolt and nut combination fasteners are used, torque values should be applied to the

NUT

instead of

the bolt head.

Tighten toothed or serrated-type lock nuts to the full torque value.

lubrication

“Grade 2” applies for hex cap screws (not hex bolts) up to 152 mm (6-in.) long. “Grade 1” applies for hex cap screws over 152 mm (6-in.) long, and for all other types of bolts and screws of any length.

Reference: JDS—G200.

2 - 8

3/20/97

SPECIFICATIONS AND INFORMATION

O-RING SEAL SERVICE RECOMMENDATIONS

O-RING SEAL

SERVICE RECOMMENDATIONS

FACE SEAL FITTINGS WITH INCH STUD ENDS TORQUE

Stud End

Stud Straight and Tube Nut

Bulkhead Union and Bulkhead Lucknut

Nominal Tube O.D./Hose I.D. Face Seal Tube/Hose End O-ring Stud Ends

Metric

Tube

O.D.

Inch Tube O.D. Thread Size

Tube Nut

Locknut

Stud End

90 Adjustable Stud Elbow

Tube Nut/

Swivel Nut

Torque

Bulkhead

Locknut

Torque

Swivel Nut

Tube Nut

90 Swivel Elbow and Tube Nut

Thread

Size

Straight Fitting or

Locknut Torque

10 -6 0.375 9.52 11/16-16 24 18 24 18 9/16-18 24 18 12 -8 0.500 12.70 13/16-16 50 37 46 34 3/4-16 46 34 16 -10 0.625 15.88 1-14 69 51 62 46 7/8-14 62 46

22 -14 0.875 22.22 1-3/16-12 102 75 102 75 1-3/16-12 122 90 25 -16 1.000 25.40 1-7/16-12 142 105 142 105 1-5/16-12 142 105 32 -20 1.25 31.75 1-11/16-12 190 140 190 140 1-5/8-12 190 140 38 -24 1.50 38.10 2-12 217 160 217 160 1-7/8-12 217 160

Dash

Size

-3 0.188 4.76 3/8-24 8 6 6 -4 0.250 6.35 9/16-18 16 12 12 9 7/16-20 12 9 8 -5 0.312 7.94 1/2-20 16 12

-12 0.750 19.05 1-3/16-12 102 75 102 75 1-1/16-12 102 75

in. mm in. N•m lb-ft N•m lb-ft in. N•m lb-ft

NOTE: Torque tolerance is + 15 minus 20%.

3/20/97

2 - 9

O-RING SEAL SERVICE RECOMMENDATIONS

SPECIFICATIONS AND INFORMATION

FACE SEAL FITTINGS WITH METRIC STUD ENDS TORQUE

Stud End

Groove For Metric

Stud Straight and Tube Nut

Bulkhead Union and Bulkhead Lucknut

Identification

Nominal Tube O.D./Hose

I.D.

Metric

Tube

Inch Tube O.D.

O.D.

Dash

Size

in. mm in. mm N•m lb-ft N•m lb-ft mm mm N•m lb-ft N•m lb-ft

Tube Nut

Groove For Metric Identification

90 Adjustable Stud Elbow

Face Seal Tube/Hose End

Tube

Thread

Size

Hex

Size

Nut/

Swivel

Nut

Torque

Stud End

Bulkhead

Locknut

Torque

Locknut

90 Swivel Elbow and Tube Nut

Swivel Nut

Tube Nut

O-ring Stud Ends, Straight Fitting or

Locknut

Thread

Size

Hex

Size

Steel or

Gray Iron

Torque

Aluminum

Torque

6 -4 0.250 6.35 9/16-18 17 16 12 12 9 M12X1.5 17 21 15.5 9 6.6 8 -5 0.312 7.94

M14X1.5 19 33 24 15 11 10 -6 0.375 9.52 11/16-16 22 24 18 24 18 M16X1.5 22 41 30 18 13 12 -8 0.500 12.70 13/16-16 24 50 37 46 34 M18X1.5 24 50 37 21 15 16 -10 0.625 15.88 1-14 30 69 51 62 46 M22X1.5 27 69 51 28 21

-12 0.750 19.05 1-3/16-12 36 102 75 102 75 M27X2 32 102 75 46 34 22 -14 0.875 22.22 1-3/16-12 36 102 75 102 75 M30X2 36 25 -16 1.000 25.40 1-7/16-12 41 142 105 142 105 M33X2 41 158 116 71 52 28 M38X2 46 176 130 79 58 32 -20 1.25 31.75 1-11/16-12 50 190 140 190 140 M42X2 50 190 140 85 63 38 -24 1.50 38.10 2-12 60 217 160 217 160 M48X2 55 217 160 98 72

NOTE: Torque tolerance is + 15 minus 20%.

2 - 10

3/20/97

SPECIFICATIONS AND INFORMATION

(6)

(9)

(12)

(18)

(34)

(46)

(75)

(90)

(

)

(

)

(

)

Special Nut

Special Washer

Angle Fitting

O-RING SEAL SERVICE RECOMMENDATIONS

O-RING FACE SEAL FITTINGS

Sealing Surface

O-ring

Sealing Surface

1. Inspect the fitting sealing surfaces. They must be free of dirt or defects.

2. Inspect the O-ring. It must be free of damage or defects.

3. Lubricate O-rings and install into groove using petroleum jelly to hold in place.

4. Push O-ring into the groove with plenty of petroleum jelly so O-ring is not displaced during assembly.

5. Index angle fittings and tighten by hand pressing joint together to insure O-ring remains in place.

6. Tighten fitting or nut to torque value shown on the chart per dash size stamped on the fitting. Do not allow hoses to twist when tightening fittings.

3. For angle fittings, loosen special nut and push special washer against threads so O-ring can be installed into the groove of fitting.

4. Turn fitting into the boss by hand until special washer or washer face (straight fitting) contacts boss face and O-ring is squeezed into its seat.

5. To position angle fittings, turn the fitting counterclockwise a maximum of one turn.

6. Tighten straight fittings to torque value shown on chart. For angle fittings, tighten the special nut to value shown in the chart while holding body of fitting with a wrench.

STRAIGHT FITTING OR SPECIAL NUT TORQUE

Thread

Size

Tor

N•m lb-ft

Number

of Flats

O-RING BOSS FITTINGS

1. Inspect boss O-ring boss seat. It must be free of dirt

2. Put hydraulic oil or petroleum jelly on the O-ring.

and defects. If repeated leaks occur, inspect for defects with a magnifying glass. Some raised defects can be removed with a slip stone.

Groove

Place electrical tape over the threads to protect Oring from nicks. Slide O-ring over the tape and into the groove of fitting. Remove tape.

O-ring

3/8-24 UNF 8

7/16-20 UNF 12

1/2-20 UNF 16

9/16-18 UNF 24

3/4-16 UNF 46

7/8-14 UNF 62 1-1/16-12 UN 102 1-3/16-12 UN 122 1-5/16-12 UN 142

1-5/8-12 UN 190 1-7/8-12 UN 217

a. Torque tolerance is ± 10 percent. b. To be used if a tor After ti boss; then ti number of flats shown.

htening fitting by hand, put a mark on nut or

hten special nut or straight fitting the

ue wrench cannot be used.

105 140 160

2 2 2 2 2

1-1/2

1 3/4 3/4 1/2

3/20/97

2 - 11

GASOLINE SPECIFICATIONS

GASOLINE SPECIFICATIONS 4–CYCLE ENGINES - NORTH AMERICA

SPECIFICATIONS AND INFORMATION

Gasoline is HIGHLY FLAMMABLE, handle it with care. DO NOT refuel machine while:

• indoors, always fill gas tank outdoors;

• machine is near an open flame or sparks;

• engine is running, STOP engine;

• engine is hot, allow it to cool sufficiently first;

• smoking. Help prevent fires:

• fill gas tank to bottom of filler neck only;

• be sure fill cap is tight after fueling;

• clean up any gas spills IMMEDIATELY;

• keep machine clean and in good repair–free of excess grease, oil, debris, and faulty or damaged parts;

• any storage of machines with gas left in tank should be in an area that is well ventilated to prevent possible igniting of fumes by an open flame or spark, this includes any appliance with a pilot light.

To prevent fire or explosion caused by STATIC ELECTRIC DISCHARGE during fueling:

• ONLY use a clean, approved POLYETHYLENE PLASTIC fuel container and funnel WITHOUT any metal

screen or filter.

CAUTION

STOP ENGINE

NO OPEN FLAME

OR SPARK

NO HOT ENGINE

NO SMOKING

NO STATIC ELECTRIC

DISCHARGE

To avoid engine damage:

• DO NOT mix oil with gasoline;

•

ONLY use clean, fresh unleaded gasoline with

an octane rating (anti-knock index) of 87 or higher

• fill gas tank at the end of each day's operation to help prevent condensation from forming inside a partially filled tank;

• keep up with specified service intervals.

Use of alternative oxygenated, gasohol blended, unleaded gasoline is acceptable as long as:

• the ethyl or grain alcohol blends DO NOT exceed 10% by volume or

• methyl tertiary butyl ether (MTBE) blends DO NOT exceed 15% by volume.

IMPORTANT: DO NOT use METHANOL gasolines

because METHANOL is harmful to the environment and to your health.

;

California Proposition 65 Warning: Gasoline engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.

WARNING

GASOLINE STORAGE

IMPORTANT: Keep all dirt, scale, water or other

foreign material out of gasoline.

Keep gasoline stored in a safe, protected area. Storage of gasoline in a clean, properly marked

GASOLINE”) POLYETHYLENE PLASTIC container WITHOUT DO NOT

gasoline or depend on fuel filters to remove water from gasoline. Use a water separator installed in the storage tank outlet. contaminated gasoline. When storing unit or gasoline, it is recommended that you add

Conditioner and Stabilizer (TY15977)

equivalent to the gasoline. directions on container and to properly discard empty container.

any metal screen or filter is recommended.

use de-icers to attempt to remove water from

BE SURE

to properly discard unstable or

John Deere Gasoline

BE SURE

(“UNLEADED

or an

to follow

2 - 12

3/20/97

SPECIFICATIONS AND INFORMATION

4–CYCLE ENGINES - EUROPE

GASOLINE SPECIFICATIONS

Gasoline is HIGHLY FLAMMABLE, handle it with care. DO NOT refuel machine while:

• indoors, always fill gas tank outdoors;

• machine is near an open flame or sparks;

• engine is running, STOP engine;

• engine is hot, allow it to cool sufficiently first;

• smoking. Help prevent fires:

• fill gas tank to bottom of filler neck only;

• be sure fill cap is tight after fueling;

• clean up any gas spills IMMEDIATELY;

• keep machine clean and in good repair–free of excess grease, oil, debris, and faulty or damaged parts;

To prevent fire or explosion caused by STATIC ELECTRIC DISCHARGE during fueling:

• ONLY use a clean, approved POLYETHYLENE PLASTIC fuel container and funnel WITHOUT any metal

screen or filter.

CAUTION

STOP ENGINE

NO OPEN FLAME

OR SPARK

NO HOT ENGINE

NO SMOKING

NO STATIC ELECTRIC

DISCHARGE

To avoid engine damage:

• DO NOT mix oil with gasoline;

•

ONLY use clean, fresh unleaded gasoline with

an octane rating (anti-knock index) of 87 or higher

• fill gas tank at the end of each day's operation to help prevent condensation from forming inside a partially filled tank;

• keep up with specified service intervals.

Use of alternative oxygenated, gasohol blended, unleaded gasoline is acceptable as long as:

• the ethyl or grain alcohol blends DO NOT exceed 10% by volume or

• methyl tertiary butyl ether (MTBE) blends DO NOT exceed 15% by volume.

IMPORTANT: DO NOT use METHANOL gasolines

because METHANOL is harmful to the environment and to your health.

;

GASOLINE STORAGE

IMPORTANT: Keep all dirt, scale, water or other

foreign material out of gasoline.

Keep gasoline stored in a safe, protected area. Storage of gasoline in a clean, properly marked

GASOLINE”) POLYETHYLENE PLASTIC container WITHOUT DO NOT

Conditioner and Stabilizer (TY15977)

equivalent to the gasoline. directions on container and to properly discard empty container.

any metal screen or filter is recommended.

use de-icers to attempt to remove water from

BE SURE

to properly discard unstable or

John Deere Gasoline

BE SURE

(“UNLEADED

or an

to follow

3/20/97

2 - 13

4–CYCLE GASOLINE ENGINE OIL

4–CYCLE GASOLINE ENGINE OIL NORTH AMERICA

IMPORTANT: Kohler command engines were

designed and built to use multi-viscosity oil. Multi-viscosity oil is required for proper operation of hydraulic valve lifters used in Kohler command engines.

Use the appropriate oil viscosity based on the expected air temperature range during the period between recommended oil changes. Operating outside of these recommended oil air temperature ranges may cause premature engine failure.

SPECIFICATIONS AND INFORMATION

SAE 10W-40

SAE 10W-30

SAE 5W-30

The following John Deere oils are

•

PLUS–4®—SAE 10W-40;

•

TURF–GARD®—SAE 10W-30;

•

PLUS–4®—SAE 10W-30

The following John Deere oil is based on their specified temperature range:

•

TORQ–GARD SUPREME®—SAE 5W-30

Other oils may be used if above John Deere oils are not available, provided they meet one of the following specifications:

• SAE 10W-40—API Service Classification SG or higher;

• SAE 10W-30—API Service Classification SG or higher;

• SAE 5W-30—API Service Classification SG or higher.

PREFERRED

;

also recommended

PREFERRED

John Deere Dealers:

reference the following publications to recommend the proper oil for your customers:

• Module DX,ENOIL2 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lubrication Sales Manual PI7032.

AIR TEMPERATURE

You may want to cross-

M58275

2 - 14

3/20/97

SPECIFICATIONS AND INFORMATION

4–CYCLE GASOLINE ENGINE OIL EUROPE

IMPORTANT: Kohler command engines were

designed and built to use multi-viscosity oil. Multi-viscosity oil is required for proper operation of hydraulic valve lifters used in Kohler command engines.

4–CYCLE GASOLINE ENGINE OIL

SAE 10W-40

SAE 10W-30

SAE 5W-30

The following John Deere oils are

• TORQ–GARD SUPREME®—SAE 10W-40;

• UNI–GARD™—SAE 10W-40;

• TORQ–GARD SUPREME®—SAE 10W-30;

• UNI–GARD™—SAE 10W-30.

The following John Deere oil is based on their specified temperature range:

• TORQ–GARD SUPREME®—SAE 5W-30;

• UNI–GARD™—SAE 5W-30.

Other oils may be used if above John Deere oils are not available, provided they meet one of the following specifications:

• CCMC Specification G4 or higher.

PREFERRED

also recommended

PREFERRED

John Deere Dealers:

reference the following publications to recommend the proper oil for your customers:

• Module DX,ENOIL2 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide.

AIR TEMPERATURE

You may want to cross-

M58275

3/20/97

2 - 15

4–CYCLE GASOLINE ENGINE OIL

BREAK–IN 4-CYCLE GASOLINE ENGINE OIL - NORTH AMERICA

IMPORTANT: ONLY use a quality break-in oil

(multi-viscosity) in rebuilt or remanufactured engines for the first 5 hours (maximum) of operation. DO NOT use oils with heavier viscosity weights than SAE 5W-30 or oils meeting specifications API SG or SH, these oils will not allow rebuilt or remanufactured engines to break-in properly.

SPECIFICATIONS AND INFORMATION

The following John Deere oil is

•

BREAK–IN ENGINE OIL

John Deere BREAK–IN ENGINE OIL

with special additives for aluminum and cast iron type engines to allow the power cylinder components (pistons, rings, and liners as well) to “wear-in” while protecting other engine components, valve train and gears, from abnormal wear. Engine rebuild instructions should be followed closely to determine if special requirements are necessary.

John Deere BREAK–IN ENGINE OIL

recommended for non-John Deere engines, both aluminum and cast iron types.

The following John Deere oil is a break-in engine oil:

•

TORQ–GARD SUPREME®—SAE 5W-30.

If the above recommended John Deere oils are not available, use a break-in engine oil meeting the following specification during the first 5 hours (maximum) of operation:

• SAE 5W-30—API Service Classification SE or higher.

PREFERRED

also recommended

is formulated

is also

BREAK-IN OIL

PREFERRED

AIR TEMPERATURE

John Deere Dealers:

reference the following publications to recommend the proper oil for your customers:

• Module DX,ENOIL4 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lubrication Sales Manual PI7032.

You may want to cross-

SAE 5W-30

M58275

IMPORTANT: After the break-in period, use the

John Deere oil that is recommended for this engine.

2 - 16

3/20/97

SPECIFICATIONS AND INFORMATION

BREAK–IN 4-CYCLE GASOLINE ENGINE OIL - EUROPE

IMPORTANT: ONLY use a quality break-in oil

(multi-viscosity) in rebuilt or remanufactured engines for the first 5 hours (maximum) of operation. DO NOT use oils with heavier viscosity weights than SAE 5W-30 or oils meeting CCMC Specification G5—these oils will not allow rebuilt or remanufactured engines to break-in properly.

4–CYCLE GASOLINE ENGINE OIL

The following John Deere oil is

•

BREAK–IN ENGINE OIL

John Deere with special additives for aluminum and cast iron type engines to allow the power cylinder components (pistons, rings, and liners as well) to “wear-in” while protecting other engine components, valve train and gears, from abnormal wear. Engine rebuild instructions should be followed closely to determine if special requirements are necessary.

John Deere recommended for non-John Deere engines, both aluminum and cast iron types.

The following John Deere oil is a break-in engine oil:

•

TORQ–GARD SUPREME®—SAE 5W-30.

If the above recommended John Deere oils are not available, use a break-in engine oil meeting the following specification during the first 5 hours (maximum) of operation:

• SAE 5W-30—CCMC Specification G4 or higher.

BREAK–IN ENGINE OIL

PREFERRED

also recommended

is formulated

is also

BREAK-IN OIL

PREFERRED

AIR TEMPERATURE

John Deere Dealers:

reference the following publications to recommend the proper oil for your customers:

• Module DX,ENOIL4 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide.

You may want to cross-

SAE 5W-30

M58275

IMPORTANT: After the break-in period, use the

John Deere oil that is specified for this engine.

3/20/97

2 - 17

HYDROSTATIC TRANSMISSION OIL

- NORTH AMERICA

Use the following oil viscosity based on the air temperature range. Operating outside of the recommended oil air temperature range may cause premature hydrostatic transmission failure.

SPECIFICATIONS AND INFORMATION

IMPORTANT: ONLY use a quality SAE 10W-30

engine oil in this transmission. DO NOT mix any other oils in this transmission. DO NOT use BIO–HY–GARD® in this transmission.

The following John Deere oils are

•

TURF-GARD®—SAE 10W-30;

•

PLUS-4®—SAE 10W-30.

Other oils may be used if above recommended John Deere oils are not available, provided they meet one of the following specifications:

• API Service Classification SG or higher.

PREFERRED

SAE 10W-30

AIR TEMPERATURE

John Deere Dealers:

reference the following publications to recommend the proper oil for your customers:

• Module DX,ENOIL2 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lubrication Sales Manual PI7032.

You may want to cross-

M58275

2 - 18

3/20/97

SPECIFICATIONS AND INFORMATION

M58275

AIR TEMPERATURE

SAE 10W-30

HYDROSTATIC TRANSMISSION OIL

- EUROPE

Use the following oil viscosity based on the air temperature range. Operating outside of the recommended oil air temperature range may cause premature hydrostatic transmission failure.

IMPORTANT: ONLY use a quality SAE 10W-30

engine oil in this transmission. DO NOT mix any other oils in this transmission. DO NOT use BIO–HY–GARD® in this transmission.

HYDROSTATIC TRANSMISSION OIL

The following John Deere oil is

•

TORQ-GARD SUPREME®—SAE 10W-30.

Other oils may be used if above recommended John Deere oils are not available, provided they meet one of the following specifications:

• CCMC Specification G4 or higher.

PREFERRED

John Deere Dealers:

reference the following publications to recommend the proper oil for your customers:

• Module DX,ENOIL2 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide.

You may want to cross-

3/20/97

2 - 19

ALTERNATIVE LUBRICANTS

SPECIFICATIONS AND INFORMATION

ALTERNATIVE LUBRICANTS

Conditions in certain geographical areas outside the United States and Canada may require different lubricant recommendations than the ones printed in this technical manual or the operator's manual. Consult with your John Deere Dealer, or Sales Branch, to obtain the alternative lubricant recommendations.

IMPORTANT: Use of alternative lubricants could

cause reduced life of the component.

If alternative lubricants are to be used, it is recommended that the factory fill be thoroughly removed before switching to any alternative lubricant.

SYNTHETIC LUBRICANTS

Synthetic lubricants may be used in John Deere equipment if they meet the applicable performance requirements (industry classification and/or military specification) as shown in this manual.

The recommended air temperature limits and service or lubricant change intervals should be maintained as shown in the operator’s manual.

Avoid mixing different brands, grades, or types of oil. Oil manufacturers blend additives in their oils to meet certain specifications and performance requirements. Mixing different oils can interfere with the proper functioning of these additives and degrade lubricant performance.

LUBRICANT STORAGE

All machines operate at top efficiency only when clean lubricants are used. Use clean storage containers to handle all lubricants. Store them in an area protected from dust, moisture, and other contamination. Store drums on their sides. Make sure all containers are properly marked as to their contents. Dispose of all old, used containers and their contents properly.

MIXING OF LUBRICANTS

In general, avoid mixing different brands or types of lubricants. Manufacturers blend additives in their lubricants to meet certain specifications and performance requirements. Mixing different lubricants can interfere with the proper functioning of these additives and lubricant properties which will downgrade their intended specified performance.

OIL FILTERS

IMPORTANT: Filtration of oils is critical to proper

lubrication performance. Always change filters regularly.

The following John Deere oil filters are PREFERRED:

• AUTOMOTIVE AND LIGHT TRUCK ENGINE OIL FILTERS.

Most John Deere filters contain pressure relief and anti-drainback valves for better engine protection.

Other oil filters may be used if above recommended John Deere oil filters are not available, provided they meet the following specification:

• ASTB Tested In Accordance With SAE J806.

John Deere Dealers:

reference the following publications to recommend the proper oil filter for your customers:

• Module DX,FILT in JDS–G135;

• Section 540, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lawn & Grounds Care Tune-Up Guide PI672.

You may want to cross-

2 - 20

3/20/97

SPECIFICATIONS AND INFORMATION

GEAR TRANSMISSION GREASE

Use the following gear grease based on the air temperature range. Operating outside of the recommended grease air temperature range may cause premature gear transmission failure.

IMPORTANT: ONLY use these specified greases in

this transmission. DO NOT mix any other greases in this transmission. DO NOT use any BIO–GREASE in this transmission.

GEAR TRANSMISSION GREASE

use the following

ONLY

PREFERRED

input shaft needle bearing

lubricant:

grease as the

• Unirex N3 Grease®—M120263.

Other greases may be used as the input shaft needle bearing lubricant if they meet or exceed the following specification:

• ASTM D–1743, NLGI Grade 1.

use the following

ONLY gear housing

PREFERRED

lubricant:

grease as the

• Shell Darina D Grease®—AM119608.

Other greases may be used as the gear housing lubricant if they meet or exceed the following specification:

• ASTM D–1743, NLGI Grade 1.

ASTM D–1743

NLGI Grade 1

AIR TEMPERATURE

John Deere Dealers:

You may want to cross-

M58275

reference the following publications to recommend the proper grease for your customers:

• Module DX,GREA1 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lubrication Sales Manual PI7032.

3/20/97

2 - 21

ANTI-CORROSION GREASE SPECIFICATIONS

This anti-corrosion grease is formulated to provide the best protection against absorbing moisture, which is one of the major causes of corrosion. This grease is also superior in its resistance to separation and migration.

The following anti-corrosion grease is

• DuBois MPG-2® Multi-Purpose Polymer Grease—M79292.

Other greases may be used if they meet or exceed the following specifications:

• John Deere Standard JDM J13A2, NLGI Grade 1.

PREFERRED

SPECIFICATIONS AND INFORMATION

JDM J13A2

NLGI Grade 1

AIR TEMPERATURE

John Deere Dealers:

reference the following publications to recommend the proper grease for your customers:

• Module DX,GREA1 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lubrication Sales Manual PI7032.

You may want to cross-

M58275

2 - 22

3/20/97

SPECIFICATIONS AND INFORMATION

GREASE SPECIFICATIONS

GREASE - NORTH AMERICA

Use the following grease based on the air temperature range. Operating outside of the recommended grease air temperature range may cause premature failures.

IMPORTANT: ONLY use a quality grease in this

application. DO NOT mix any other greases in this application. DO NOT use any BIO–GREASE in this application.

The following John Deere grease is

PREFERRED

• NON-CLAY HIGH-TEMPERATURE EP GREASE®—JDM J13E4, NLGI Grade 2.

Other greases may be used if above preferred John Deere grease is not available, provided they meet the following specification:

• John Deere Standard JDM J13E4, NLGI Grade 2.

GREASE - EUROPE

Use the following grease based on the air temperature range. Operating outside of the recommended grease air temperature range may cause premature failures.

IMPORTANT: ONLY use a quality grease in this

application. DO NOT mix any other greases in this application. DO NOT use any BIO–GREASE in this application.

The following John Deere grease is

PREFERRED

• GREASE–GARD™—JDM J13E4, NLGI Grade 2.

Other greases may be used if above preferred John Deere grease is not available, provided they meet the following specification:

• John Deere Standard JDM J13E4, NLGI Grade 2.

JDM J13E4

NLGI Grade 2

AIR TEMPERATURE

John Deere Dealers:

You may want to cross-

M58275

reference the following publications to recommend the proper grease for your customers:

• Module DX,GREA1 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide;

• Lubrication Sales Manual PI7032.

JDM J13E4

NLGI Grade 2

AIR TEMPERATURE

John Deere Dealers:

You may want to cross-

M58275

reference the following publications to recommend the proper grease for your customers:

• Module DX,GREA1 in JDS–G135;

• Section 530, Lubricants & Hydraulics, of the John Deere Merchandise Sales Guide.

3/20/97

2 - 23

SERIAL NUMBER LOCATIONS

SPECIFICATIONS AND INFORMATION

SERIAL NUMBER LOCATIONS ENGINE SERIAL NUMBER SUFFUX

Domestic Australia Export

STX38/Gear/12.5 (Steel Cam ) = 8 STX38/Gear/12.5 (Steel Cam ) = 8 STX38/Gear/12.5 (Plastic Cam ) =4 STX38/Hydro/12.5 (Steel Cam ) = 8 STX38/Hydro/12.5 (Steel Cam ) =8 STX38/Hydro/14 (Plastic Cam ) =9 STX46/Gear/14 (Plastic Cam ) = 9 STX46/Gear/14 (Plastic Cam ) = 9 STX46/Hydro/14 (Plastic Cam ) =9 STX46/Hydro/14 (Plastic Cam ) =9

IMPORTANT: When working on machines or

components that are covered by warranty, it is IMPORTANT that you include the transporter product identification number and the component serial numbers on the warranty claim form.

The location of transporter identification number and component serial numbers are shown.

TRACTOR IDENTIFICATION NUMBER

M55792

GEAR TRANSAXLE SERIAL NUMBER

M55792

Gear transaxle serial number sticker (D) is on rear of housing.

HYDROSTATIC TRANSMISSION SERIAL NUMBER

Tractor identification number plate (A) is located on the rear of frame.

ENGINE SERIAL NUMBER

M55791

Tractor engine serial number sticker (C) is located on fan shroud and bar code sticker (B) is on air filter housing on left side of engine.

2 - 24

M58249

Serial number (E) is stamped into top of upper case half. It is only accessible with hydro removed.

3/20/97

ENGINE

CONTENTS

Page

ENGINE

SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

GENERAL SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

TEST AND ADJUSTMENT SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

REPAIR SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TORQUE SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

ESSENTIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

OTHER MATERIALS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

SERVICE PARTS KITS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

DIAGNOSIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

MAIN COMPONENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

ENGINE HARD TO START AND/OR ENGINE STARTER KICKS OUT. . . . . . . . . . 16

ENGINE BACKFIRES, HAS LOW POWER, WILL NOT START,

OR TURNS OVER SLOWLY AND LOCKS UP . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

TESTS AND ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

THROTTLE CABLE ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

FAST IDLE SPEED ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

SLOW IDLE SPEED ADJUSTMENT

—NON CARB/EPA (EARLY MODELS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

SLOW IDLE SPEED ADJUSTMENT

—CARB/EPA STX38 (SN 210001— ) & STX46 . . . . . . . . . . . . . . . . . . . . . . . . . 21

CYLINDER COMPRESSION TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

AUTOMATIC COMPRESSION RELEASE TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

CRANKCASE VACUUM TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

FUEL FLOW TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

OIL PRESSURE TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

FUEL AND AIR SYSTEM REPAIR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

FUEL TANK AND DASH PANEL COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . 25

REMOVE AND INSTALL FUEL TANK AND DASH PANEL ASSEMBLY . . . . . . . . . 26

REPLACE FUEL FILTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

AIR INTAKE SYSTEM COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

REMOVE AND INSTALL CARBURETOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

INSPECT CARBURETOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

ENGINE REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

REMOVE AND INSTALL ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

REMOVE AND INSTALL ROCKER ARMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

INSPECT PUSH ROD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

REMOVE AND INSTALL CYLINDER HEAD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

REMOVE AND INSTALL VALVES AND SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . 33

INSPECT CYLINDER HEAD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

INSPECT VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

ANALYZE VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

INSPECT VALVE GUIDES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3/20/97

3 - 1

CONTENTS

RECONDITION VALVE SEATS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

LAP VALVES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

INSPECT BREATHER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

REMOVE AND INSTALL FLYWHEEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

REMOVE AND INSTALL CAMSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

INSPECT CAMSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

MEASURE CAMSHAFT END PLAY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

HYDRAULIC VALVE LIFTERS—REMOVE AND INSTALL . . . . . . . . . . . . . . . . . . . 38

HYDRAULIC VALVE LIFTERS—INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

BALANCER SHAFT REMOVAL & INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 39

BALANCER SHAFT INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

GOVERNOR REMOVAL & INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

GOVERNOR INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

REMOVE PISTON ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

ANALYZE PISTON RING WEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

ANALYZE PISTON WEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

PISTON ASSEMBLY—DISASSEMBLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

PISTON INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

PISTON RING END GAP MEASUREMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

PISTON RING SIDE CLEARANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

PISTON ASSEMBLY MEASUREMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

PISTON ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

INSTALL PISTON ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

INSTALL CONNECTING ROD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

CRANKSHAFT REMOVAL & INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

CRANKSHAFT & MAIN BEARING INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . 47

CRANKSHAFT ALIGNMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

REMOVE AND INSTALL OIL PAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

REMOVE AND INSTALL OIL PAN SEAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

REMOVE AND INSTALL CRANKCASE OIL SEAL . . . . . . . . . . . . . . . . . . . . . . . . . 49

INSPECT OIL PICKUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

OIL PUMP RELIEF VALVE INSPECT ION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

OIL PUMP INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

CYLINDER BLOCK REMOVE & INSTALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

CYLINDER BLOCK INSPECT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

CYLINDER BORE DEGLAZING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

REBORE CYLINDER BLOCK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

ENGINE

3 - 2

3/20/97

ENGINE

SPECIFICATIONS

GENERAL SPECIFICATIONS

Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kohler

Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Command LT

STX30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CV12.5—1216s

STX38 (Serial No. —270000) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CV12.5—1215

STX38 (Domestic & Export) (Serial No. 210001—270000) . . . . . . . . . CV12.5S—1270

STX38 (Export Gear) (Serial No. 270001—595000). . . . . . . . . . . . . . . CV12.5S—1270

STX38 (Domestic Gear & Hydro) (Serial No. 270001—595000) . . . . . . CV13S—21509

STX38 (Export Hydro) (Serial No. 240001—270000). . . . . . . . . . . . . . . . CV14S—1463

STX38 (Export Hydro) (Serial No. 270001—595000). . . . . . . . . . . . . . . . CV14S—1463

STX46 (Domestic Gear & Hydro) (Serial No. 240001—270000) . . . . . . . CV14S—1463

STX46 (Domestic Gear & Hydro) (Serial No. 270001—595000) . . . . . . CV15S—41521

STX46 (Australia Hydro) (Serial No. 270001—595000) . . . . . . . . . . . . . CV15S—41521

Type . . . . . . . . . . . . . . Gasoline, Air Cooled, Single Cylinder, 4-Cycle, Overhead Valve

Power: CV12.5—1270 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.33 kW (12.5 hp)

CV13S—21509 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.69 kW (13.0 hp)

CV14S—1463 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5 kW (14.0 hp)

CV15S—41521 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.19 kW (15.0 hp)

Bore (12.5, 13, 14 hp). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 mm (3.43 in.)

Bore (15 hp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 mm (3.60 in.)

Stroke (All) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 mm (2.64 in.)

Displacement (12.5, 13, 14 hp). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 cc (24.3 cu-in.)

Displacement (15 hp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426 cc (26.0 cu-in.)

Compression Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2:1 Cranking—8.5:1 Running

Compression Release. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic/Centrifugal

Crankshaft Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vertical (counterbalanced)

Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gerotor Pump (0—60 psi)

Oil Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Full Flow (W/O By-Pass Valve)

Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .John Deere Turf-Gard

Warm Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10W30

Cold Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5W30

Crankcase Capacity (with filter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 L (1.9 U.S. qt)

Lubrication Interval . . . . . . . . . 50 Hours First Change, Every 100 Hours After or Yearly

Air Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paper With Outer Foam Element

Fuel Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Replaceable (In-Line Type)

Fuel Type . . . . . . . . . . . . . . . . . . . . . . . . . . . .Regular Unleaded—87 Octane Or Higher

Gasoline/Alcohol Blends. . . . . . .Up To 10% Ethyl Alcohol-90% Unleaded (By Volume)

Gasoline/Ether Blends . . . . . . . . . . . . . Up To 15% MTBE-85% Unleaded (By Volume)

Fuel Shut-Off Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Replaceable (In-Line Type)

Fuel Shut-Off Solenoid (Optional). . . . . . . . Replaceable (Below Carburetor Float Bowl)

Weight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39.54 kg (87 lbs)

4/23/97

3 - 3

SPECIFICATIONS

TEST AND ADJUSTMENT SPECIFICATIONS

Engine:

Valve Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . None (hydraulic lifters)

Oil Pressure (Minimum at 1250 rpm) . . . . . . . . . . . . . . . . . . . . . . . . . . 124 kPa (18 psi)

Crankcase Vacuum (Minimum At Operating Temp.) . . .25 mm (1 in.) Water Movement

Automatic Compression Release Minimum Lift (Engine Cold) . . . . . .0.25 mm (0.01 in.)

Fuel/Air System:

Carburetor Slow Idle Mixture Screw Initial Setting . . . . . . Lightly Seat, Then 1 Turn Out

Slow Idle Speed—Domestic and Export. . . . . . . . . . . . . . . . . . . . . . . . . . 1650 ±75 rpm

Fast Idle Speed—Domestic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3350 ±50 rpm

Fast Idle Speed—Export. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3000 ±50 rpm

REPAIR SPECIFICATIONS

Cylinder Head:

Cylinder Head Flatness (Maximum Warpage) . . . . . . . . . . . . . . . . 0.076 mm (0.003 in.)

Push Rod:

Maximum Bend. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.76 mm (0.030 in.)

ENGINE

Valves and Valve Lifters:

Hydraulic Lifter Clearance. . . . . . . . . . . . . . . 0.0124—0.0501 mm (0.0005—0.0020 in.)

Intake Valve-to-Guide Clearance . . . . . . . . . . . 0.038—0.076 mm (0.0015—0.0030 in.)

Intake Valve Stem OD. . . . . . . . . . . . . . . . . . . . . . . .6.982—7.000 (0.2749—0.2756 in.)

Exhaust Valve Stem OD . . . . . . . . . . . . . . . . . . . . . . . . 6.970—6.988 (0.2744—0.2751)

Exhaust Valve-to-Guide Clearance. . . . . . . . . . 0.050—0.088 mm (0.0020—0.0035 in.)

Intake Valve Guide ID:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.038—7.058 mm (0.2771—0.2779 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.134 mm (0.2809 in.)

Exhaust Valve Guide ID:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.038—7.058 mm (0.2771—0.2779 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.159 mm (0.2819 in.)

Valve Guide Reamer:

Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.048 mm (0.2775 in.)

Oversize (0.25 mm). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.298 mm (0.2873 in.)

Intake Valve Lift (Minimum—Engine Cold) . . . . . . . . . . . . . . . . . . . .8.96 mm (0.353 in.)

Exhaust Valve Lift (Minimum—Engine Cold) . . . . . . . . . . . . . . . . . . 9.14 mm (0.360 in.)

Valve Face Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45°

Valve Seat Angle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.5

3 - 4

4/23/97

ENGINE

SPECIFICATIONS

REPAIR SPECIFICATIONS (Continued)

Rocker Arms:

Rocker Arm I.D.

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.837—16.127 mm (0.63—0.64 in.)

Wear Limit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15.727 mm (0.619 in.)

Rocker Shaft:

Rocker Shaft O.D.

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.837—16.127 mm (0.63—0.64 in.)

Wear Limit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15.727 mm (0.619 in.)

Crankshaft:

End Play . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0575—0.4925 mm (0.0023—0.0194 in.)

Crankshaft Bore (Crankcase Half) ID:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.965—45.003 mm (1.7703—1.7718 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45.016 mm (1.7723 in.)

Clearance (New) . . . . . . . . . . . . . . . . . . . . . . . . 0.03—0.09 mm (0.0012—0.0035 in.)

Crankshaft Bore (Oil Pan Half):

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.965—45.003 mm (1.7703—1.7718 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45.016 mm (1.7723 in.)

Clearance (New) . . . . . . . . . . . . . . . . . . . . . . . . 0.03—0.09 mm (0.0012—0.0035 in.)

Main Bearing Journal OD (Flywheel End):

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.913—44.935 mm (1.7682—1.7691 in.)

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44.84 mm (1.765 in.)

Maximum Taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.022 mm (0.0009 in.)

Maximum Out-of-Round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 mm (0.0010 in.)

Main Bearing Journal OD (Oil Pan End):

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.915—41.935 mm (1.6502—1.6510 in.)

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41.86 mm (1.648 in.)

Maximum Taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.020 mm (0.0008 in.)

Maximum Out-of-Round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 mm (0.0010 in.)

Connecting Rod Journal OD:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38.958—38.970 mm (1.5338—1.5343 in.)

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38.94 mm (1.5328 in.)

Maximum Taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.012 mm (0.0005 in.)

Maximum Out-of-Round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 mm (0.0010 in.)

Crankshaft Total Indicated Runout (TIR):

PTO End (In Engine). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 mm (0.0059 in.)

Entire Crankshaft (In Bench V-Blocks) . . . . . . . . . . . . . . . . . . . .0.10 mm (0.0039 in.)

4/23/97

3 - 5

SPECIFICATIONS

REPAIR SPECIFICATIONS (Continued)

Camshaft:

End Play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.076—0.127 mm (0.003—0/005 in.)

Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025—0.063 mm (0.0010—0.0025 in.)

Bore ID:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.000—20.025 mm (0.7874—0.7884 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20.038 mm (0.7889 in.)

Bearing OD:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.962—19.975 mm (0.7859—0.7864 in.)

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.959 mm (0.7858 in.)

Balance Shaft:

End Play . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0575—0.3625 mm (0.0023—0.0143 in.)

Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025—0.063 mm (0.0009—0.0025 in.)

Bore ID:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.000—20.025 mm (0.7874—0.7884 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20.038 mm (0.7889 in.)

Balance Shaft Bearing OD:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.962—19.975 mm (0.7859—7864 in.)

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.959 mm (0.7858 in.)

ENGINE

Cylinder Bore, Piston and Rings:

Cylinder Bore ID (12.5, 13, 14 hp):

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87.000—87.025 mm (3.4252—3.4262 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87.063 mm (3.4277 in.)

Cylinder Bore ID (15 hp):

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90.000—90.025 mm (3.5433—3.5443 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90.63 mm (3.5681 in.)

Maximum Out-of-Round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.12 mm (0.0047 in.)

Maximum Taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 mm (0.0020 in.)

Piston-To-Pin Clearance. . . . . . . . . . . . . . . . . . 0.006—0.017 mm (0.0002—0.0007 in.)

Piston Pin Bore ID:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.006—19.012 mm (0.7483—0.7485 in.)

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.025 mm (0.7490 in.)

Piston Pin OD:

New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.995—19.000 mm (0.7478—0.7480 in.)

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18.994 mm (0.74779 in.)

Top Compression Ring-To-Groove Side Clearance

12.5, 13, 14 hp . . . . . . . . . . . . . . . . . . . . . . . 0.040—0.105 mm (0.0016—0.0041 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.060—0.105 mm (0.0023—0.0041 in.)

Middle Compression Ring-To- Groove Side Clearance

12.5, 13, 14 hp . . . . . . . . . . . . . . . . . . . . . . . 0.040—0.072 mm (0.0016—0.0028 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040—0.085 mm (0.0015—0.0002 in.)

Oil Control Ring-To-Groove Side Clearance

12.5, 13, 14 hp . . . . . . . . . . . . . . . . . . . . . . . 0.551—0.675 mm (0.0217—0.0266 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.176—0.026 (0.0069—0.0010 in.)

Top and Center Compression Ring End Gap

New Bore:

12.5, 13, 14 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3—0.5 mm (0.012—0.020 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.27—0.51 mm (0.010—0.020 in.)

Used Bore (Maximum)

All . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.77 mm (0.030 in.)

3 - 6

4/23/97

ENGINE

REPAIR SPECIFICATIONS (Continued)

Piston Thrust Face OD:

New:

12.5, 13, 14 hp . . . . . . . . . . . . . . . . . . . . 86.941—86.959 mm (3.4229—3.4236 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . .89.951—89.969 mm (3.5413—3.5420 in.)

Minimum:

12.5, 13, 14 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.814 mm (3.4179 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89.824 mm (3.5363 in.)

Piston Thrust Face-To-Cylinder Bore Clearance

New:

12.5, 13, 14 hp. . . . . . . . . . . . . . . . . . . . . . . . . .0.041—0.044 mm (0.0016—0.0017 in.)

15 hp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.031—0.043 mm (0.0012—0.0016 in.)

Connecting Rod:

Crankpin End Clearance

New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.030—0.055 mm (0.0012—0.0022 in.)

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.07 mm (0.0025 in.)

Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.18—0.41 mm (0.007—0.016 in.)

Piston Pin Clearance . . . . . . . . . . . . . . . . . . . . .0.015—0.028 mm (0.0006—0.0011 in.)

Piston Pin End ID:

New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.015—19.023 mm (0.7486—0.7489 in.)

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.036 mm (0.7495 in.)

SPECIFICATIONS

Governor::

Crankcase Cross Shaft Bore ID:

New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.025—6.050 mm (0.2372—0.2382 in.)

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.063 mm (0.2387 in.)

Cross Shaft OD:

New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.975—6.000 mm (0.2352—0.2362 in.)

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.962 mm (0.2347 in.)

Crankcase Bore-To-Cross Shaft Clearance. . . .0.025—0.075 mm (0.0010—0.0030 in.)

Gear Shaft OD:

New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.990—6.000 mm (0.2358—0.2362 in.)

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.977 mm (0.2353 in.)

Gear Shaft-To- Gear Bore Clearance . . . . . . . .0.015—0.140 mm (0.0006—0.0055 in.)

4/23/97

3 - 7

SPECIFICATIONS

TORQUE SPECIFICATIONS (Alphabetical Order)

Air Cleaner Base Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.9 N•m (88 lb-in.)

Cylinder Head Cap Screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 N•m (30 lb-ft.)

Connecting Rod Cap Screws:

8mm Straight Shank Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.6 N•m (200 lb-in.)

Step Down Shank Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.6 N•m (130 lb-in.)

6mm Straight Shank Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 N•m (100 lb-in.)

Engine Mounting Cap Screws . . . . . . . . . . . . . . . . . . 27.1—46.2 N•m (240—408 lb-in.)

Fan Cap Screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.9 N•m (88 lb-in)

Flywheel Cap Screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 N•m (50 lb-ft)

Fuel Pump/Cover Screw

New Installation (Thread Forming). . . . . . . . . . . . . . . . . . . . . . . . . 9.0 N•m (85 lb-in.)

Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 N•m (65 lb-in.)

Fuel Bowl Nut. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 N•m (35 lb-in.)

Governor Control Panel Screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.9 N•m (88 lb-in.)

Ignition Module Screw

New Installation (Thread Forming). . . . . . . . . . . . . . . . . . . . . . . . . 6.2 N•m (55 lb-in.)

Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 N•m (35 lb-in.)

Muffler Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.4 N•m (216 lb-in.)

Oil Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7—9.0 N•m (50—80 lb-in.)

Oil Filter Drain Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3—9.0 N•m (65—80 lb-in.)

Oil Pan Cap Screw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.4 N•m (216 lb-in.)

Oil Pump Cover Screw

New Installation (Thread Forming). . . . . . . . . . . . . . . . . . . . . . . . . 6.2 N•m (55 lb-in.)

Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 N•m (35 lb-in.)

Rocker Arm Pivot Cap Screw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 N•m (124 lb-in.)

Spark Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38—43.4 N•m (28—32 lb-ft)

Stator Cap Screw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 N•m (35 lb-in.)

Valve Cover Cap Screw

New Installation (Thread Forming). . . . . . . . . . . . . . . . . . . . . . . . 10.7 N•m (95 lb-in.)

Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 N•m (65 lb-in.)

ENGINE

3 - 8

4/23/97

ENGINE

SERVICE EQUIPMENT AND TOOLS

Order tools from your SERVICEGARD Catalog. Some tools may be available from a local supplier.

Name Use

Valve Spring Compressor Remove and install valve springs Telescoping Gauge Measure valve guides

Measure inside diameter of parts.

Outside Micrometer Measure valve stem

Measure outside diameter of parts.

Measure camshaft journals & lobes Valve Guide Reamer Ream valve guides Valve Seat Cutter Cut valve seats Dial Indicator Check push rods and valves for bend

Measure crankshaft end play. Vacuum Cup Tool Lap valve Strap Wrench Hold flywheel Telescoping Gauge Measure camshaft bearing surface

Measure cylinder I.D. Ridge Reamer Clean cylinder bore. Piston Ring Expander Remove and install piston rings. Ring Compressor Install piston. Ring Groove Cleaner Clean piston ring grooves. Seal Driver Install oil seals. Cylinder Hone Bore cylinder block. Flex Hone Deglaze/crosshatch cylinder. Oil Pressure Test Kit Perform Oil Pressure Test

SPECIFICATIONS

ESSENTIAL TOOLS

Number Name Use

D20020WI Standard Size Valve Guide Reamer

(7.05 mm) D05351ST Spark Tester Tests spark plug JDG705 Oversize Valve Guide Reamer

(7.25 mm)

Clean or size valve guide to original size.

Bores valve guide to proper size for oversize valve.

OTHER MATERIALS

Number Name Use

RTV Silicone Sealant Seal valve cover.

Prussian Blue Compound Check valve seat contact.

Valve Lap Compound Lap valves.

SCOTCH-BRITE® Pad Clean cylinder head.

Zinc Oxide/Wood Alcohol Check block for cracks.

SCOTCH-BRITE® is a trademark of the 3M Company.

SERVICE PARTS KITS

The following kit is available through your parts catalog:

Camshaft Shim Kit, Oversize Piston and Ring Kits, Undersize Connecting Rod, Oil Pressure Test Kit.

4/23/97

3 - 9

TROUBLESHOOTING

Problem or Symptom

ENGINE

Check or Solution

Spark plug fouled or incorrect gap. Incorrect spark plug.

Defective ignition compon

Starter worn. Cranking rpm too slow, cables corroded, battery weak. Engine overloaded.

Fuel tank outlet restricted, shut-off valve not fully open, fuel filter or line restricted. Fuel stale, contains water, or wrong type.

Air filter element plugged or oil soaked.

ents.

Engine cranks but will not

start or starts hard

Engine will not stay running or

runs rough

Engine stalls frequently

Engine backfires

Engine surges, uneven or

uncontrolled rpm

Engine misses

Low power under load

Engine has no spark

Engine will not crank

Exhaust black, engine

floods or burns rich

Exhaust smoke blue or high

oil consumption

Engine has low oil pressure

Fuel in oil

Engine overheats

Excessive engine noise or

vibration start or starts hard

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●●● ● ● ● ●●

●●●●●●● ●● ● ●

●●● ●●● ● ●

Choke, throttle, or governor linkage worn or out of adjusted. Carburetor set too rich.

Carburetor worn, contaminated with debris or varnish. Passages plugged. Wrong jets or adjusted too lean.

Carburetor, intake manifold, or cylinder head gaskets leaking.

Low compression: worn piston, rings, cylinder, valves. Warped head.

Valve clearance incorrect. Burned or warped valves and seats. Defective springs.

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●●●●●●● ●

●●● ●●● ●●●●●

●●●●●●● ●

3 - 10

4/23/97

ENGINE

TROUBLESHOOTING

Problem or Symptom

Check or Solution

Engine oil viscosity or level incorrect. Engine oil filter restricted. Oil pump worn or passages obstructed.

Engine gaskets or seals leaking.

Crankcase breather restricted, reed valve damaged, clearance incorrect, or drain hole plugged.

Valve guides or seals worn or leaking. Valve stems worn.

Worn, stuck, or broken piston rings. Cylinder bore worn. Check compression and vacuum.

Engine cranks but will not

start or starts hard

Engine will not stay running or

runs rough

Engine stalls frequently

Engine backfires

Engine surges, uneven or

uncontrolled rpm

Engine misses

Low power under load

Engine has no spark

Engine will not crank

Exhaust black, engine

floods or burns rich

Exhaust smoke blue or high

oil consumption

Engine has low oil pressure

Fuel in oil

Engine overheats

Excessive engine noise or

vibration start or starts hard

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●●●●●●● ● ●●

●●●●●●● ●●●●●

Connecting rod or crankshaft bearings worn. Internal wear limits out of specification.

Engine mounting hardware loose or broken.

Continued on next page

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4/23/97

3 - 11

TROUBLESHOOTING

Problem or Symptom

Check or Solution

Dirt in carburetor. Float sticking. Clean carb, replace filter, check float.

Vapor lock. Check temperature of fuel system. Clear vent in top of fuel cap.

Fuel overflows carburetor

vent

Engine stops when hot

Engine races or runs one

speed

Engine clatters

Engine won’t run

●

● ●

White smoke on start-up

Engine runs slow &clicks

Engine runs on after

shutdown

Engine won’t shut off

Hydraulic lifters are noisy

ENGINE

Bent push rods after new

lifters were installed

Hydraulic lifters over-

extended.

Fuel shutoff valve closed.

Move governor shaft with engine running, check for resistance.

Lifter is collapsed. Lifter is stuck in bore. Water in fuel bowl of

carburetor. Engine RPM too low;

automatic compression release still on. Adjust low idle speed.

Inspect ignition switch and ground.

Inspect engine ground cable

Adjust idle speed to specs. Move throttle to idle before shutdown.

●

● ●

●●

● ●

● ● ●

Inspect piston, valves, cylinder head & exhaust for high carbon build-up.

“Prime” hydraulic lifters “Bleed” hydraulic lifters Check oil level

3 - 12

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4/23/97

ENGINE

NOTES

TROUBLESHOOTING

4/23/97

3 - 13

DIAGNOSIS

DIAGNOSIS MAIN COMPONENTS

Test Conditions:

• Machine PARKED on level surface.

• Park brake LOCKED.

• Key switch OFF.

• Transaxle/Hydro in NEUTRAL.

Test/Check Point Normal If Not Normal

ENGINE

1. Engine dipstick. Oil level between “L” and “F” marks on dipstick.

Oil not burnt or contaminated with metal particles or fuel.

Minimum crankcase vacuum 101.6 mm (4 in.).

2. Crankcase, head, and oil filter. No external oil leakage and filter element clean.

3. Cylinder head. Minimum compression 345 kPa (50 psi).

4. Carburetor. Float chamber full of clean fresh fuel.

Needle valve, passages, and jets free from varnish or debris.

Float assembly functioning properly. Main jet correct for elevation. SLOW idle 1650 ± 75 rpm.

Domestic FAST idle 3350 ± 50 rpm. Export FAST idle 3000 ± 50 rpm.

Choke, throttle, and governor set and functioning properly.

Add proper amount of oil to bring level to “F” mark.

Change oil and filter and inspect for cause of contamination.

Check breather. Check gaskets and seals for leaks.

Replace leaky gaskets, seals, oil filter, or drain plug.

Adjust valves. Check ACR. Check condition of valves, pistons, rings, cylinders.

Check for fuel in tank. Replace fuel in tank. Check tank vent. Check for plugged, damaged or pinched fuel lines.

Clean or replace carburetor.

Replace components as necessary. Replace main jet with correct size. Check linkage and adjust

carburetor.

Check linkage and adjust.

5. Air filter. Air filter element and canister clean and undamaged.

Hardware tight.

6. Fan, cylinder and head fins. Fan shroud and cylinder/head fins clean.

Fins not cracked or broken.

7. Internal components. Wear within limits, all hardware tight, no excessive vibrations.

3 - 14

Replace filter. Repair or replace canister.

Tighten or replace hardware. Clean thoroughly.

Replace fan or cylinder or head. Inspect, repair, or replace

components as necessary.

4/23/97

ENGINE

DIAGNOSIS

M55814

M55909

4/23/97

M55927

3 - 15

DIAGNOSIS

ENGINE HARD TO START AND/OR ENGINE STARTER KICKS OUT

NOTE: Use correct starting procedure as listed in

operator’s manual. The procedure of cranking the engine for 5 seconds and waiting for 10 seconds will improve starting and decrease total cranking time. The 10 second pause allows fuel in the manifold time to evaporate for improved combustion, reducing the chance of flooding and muffler backfire.

Test Conditions:

• Control lever in full choke position.

• Crank engine for 5 seconds. If engine does not start, pause for 10 seconds, then crank for 5 more seconds. Continue this 5 seconds on, 10 seconds off cycle until engine starts. If starter kicks out see step 8. When engine tries to start, continue cranking beyond the 5 seconds of that cycle until it starts.

ENGINE

• As engine warms up, move choke control back gradually. This will help to lessen excessive exhaust smoke, engine “loading up”, or backfire.

Test/Check Point Normal If Not Normal

1. Cranking speed. At least 300 RPM. If cranking speed is below 300 RPM check the following: Low battery output—Load test battery for correct amperage output. Engine oil weight too heavy.—Only multi-viscosity oil is recommended. Battery or starter terminals corroded. Starter failure. Automatic compression release (ACR) is not working correctly.

2. Choke adjustment. Choke plate must be completely

closed when throttle lever is in full choke position.

3. Spark plug.

Use in line spark tester (D-05351ST)

4. Carburetor Must have adequate supply of fresh,

Clean, undamaged, and gapped correctly 1.0 mm (0.04 in.). Spark plug should provide a strong blue spark.

clean fuel.

Adjust throttle cable, choke, governor, and idle speeds.

Repair or replace.

Perform fuel flow test. Connect a remote, gravity feed tank with fresh fuel after performing fuel flow test. This procedure will identify stale fuel problem. Clean carburetor.

5. Air cleaner. Clean and undamaged. Clean or replace foam pre-cleaner and air filter element as needed.

3 - 16

4/23/97

ENGINE

Test/Check Point Normal If Not Normal

6. Cylinder compression. 40—90 psi Low compression (below 40 psi) can be the result of a stuck valve or automatic compression release (ACR) not functioning correctly. A stuck valve could be caused by stale fuel or an over extended hydraulic lifter. High compression (above 90 psi) can be the result of the ACR not functioning correctly.

7. Flywheel key. Not damaged or partially sheared. Replace

8. Starter Should not kick out. Engine oil weight too heavy. Only multi-viscosity oil is recommended. Replace UTC starter with Eaton starter (only replace starter if the proper oil does not provide better starting performance). Eaton starter is standard on 1996 model year STX’s (270001— ).

DIAGNOSIS

ENGINE BACKFIRES, HAS LOW POWER, WILL NOT START, OR TURNS OVER SLOWLY AND LOCKS UP

STX38—EXPORT MODELS ONLY (M00STXC210001—271587) (M00STXE210001—271696)

IMPORTANT: Proceed with this diagnosis only after

completing the procedures starting on page 3-16.

Test/Check Point Normal If Not Normal

1. Plastic cam gear. Plastic cam gear “Not” rotated on

metal hub of camshaft.

STX46— (M00STXF240001—270000) (M00STXG240001—270000)

Replace plastic gear camshaft with metal gear camshaft. Replace any related valve train components that have been damaged or do not meet specifications. This could include valves, rocker arms, and push rods. Make sure hydraulic lifters are “bled” and “primed” before assembly.

2. Automatic compression

release (ACR) spring.

4/23/97

Spring should not be binding on retaining rivet.

Replace plastic gear camshaft with metal gear camshaft.Replace any related valve train components that have been damaged or do not meet specifications. This could include valves, rocker arms, and push rods. Make sure hydraulic lifters are “bled” and “primed” before assembly.

3 - 17

TESTS AND ADJUSTMENTS

ENGINE

TESTS AND ADJUSTMENTS

THROTTLE CABLE ADJUSTMENT

Reason:

To make sure the throttle cable moves the throttle and choke control lever through its full range of movement.

Equipment:

• 6.4 mm (0.25 in.) Drill Bit

Procedure:

1. Move throttle lever to FAST idle position.

CHOKE ADJUSTMENT

Reason:

To make sure the choke plate is fully closed when the throttle lever is in the full choke position. Correct adjustment also makes sure choke is completely open in the fast idle position.

Equipment:

• 6.4 mm (0.25 in.) Drill Bit

Procedure:

NOTE: Adjust throttle cable before adjusting choke.

1. Move throttle lever to CHOKE position then back to FAST idle position.

M55933

2. Align hole in throttle control lever with hole (A) in throttle control plate. Put a

6.4 mm (0.25-in.)

drill bit through holes to keep the throttle control lever from moving. Be sure drill bit is perpendicular to the throttle control plate.

3. Loosen cap screw (B) and pull throttle cable housing tight. Tighten cap screw.

4. Remove drill bit.

5. Move throttle lever to the full choke position. Make sure throttle lever is held up against throttle plate. Choke should be fully closed.

6. Move throttle lever through full range to be sure linkage is not binding.

M55933

2. Align hole in throttle control lever with hole in throttle control plate. Put a

6.4 mm (0.25 in.)

drill bit (C) through holes to keep the throttle control lever from moving. Be sure drill bit is perpendicular to the throttle control plate.

3. Turn screw (A) counterclockwise until screw does not contact the choke control lever (B).

4. Turn screw clockwise until screw just touches the choke control lever.

5. Remove drill bit.

6. Move throttle lever to full choke position.

7. Try to move choke rod (D) forward (choke rod should not move). If the choke rod moves forward, the choke plate is not fully closed. Carefully bend the choke rod at Vee bend (E) until the choke plate is fully closed.

8. Move throttle lever to be sure choke linkage is not binding.

3 - 18

4/23/97

ENGINE

GOVERNOR ADJUSTMENT

Reason:

To make sure the governor shaft contacts the flyweight plunger when the engine is stopped.

NOTE: Adjust throttle cable before adjusting governor

linkage.

TESTS AND ADJUSTMENTS

Procedure:

1. Move throttle lever to FAST idle position.

M55935

2. Loosen nut (A).

3. Hold top of governor arm (B) toward carburetor. Turn governor shaft (C) counter-clockwise until it stops. Hold governor shaft and tighten nut.

4. Move throttle lever through full range to be sure linkage is not binding.

5. Governor spring (D) should be installed in the hole closest to governor shaft. If governor is not responding properly, replace spring and readjust fast idle speed. If spring did not correct the problem, repair governor.

FAST IDLE SPEED ADJUSTMENT

Reason:

To set engine fast idle rpm.

Equipment:

• JTO5719 Photo Tachometer

Procedure:

1. Move transaxle shift lever to neutral position. Engage park brake.

M55933

2. Put reflective tape on blower housing screen.

3. Start and run engine at MEDIUM idle for five minutes.

Engine will be HOT. Be careful not to burn skin.

4. Move throttle lever to FAST idle position.

5. Align holes of throttle lever and throttle control plate with 6.4 mm (0.25 in.) drill bit (A). This keeps the throttle control lever from moving during adjustment. Be sure drill bit is perpendicular to the throttle control plate.

6. Use a photo tachometer to check engine rpm at the blower housing screen.

Specifications: Domestic fast idle speed setting . . . 3350 ± 50 rpm

Export fast idle speed setting. . . . . . 3000 ± 50 rpm

Control panel screw torque. . . . . 9.9 N•m (88 lb-in.)

Results:

• If fast idle speed does not meet the specifications, loosen cap screws (B).

• Move throttle control plate (C) upward to increase rpm or downward to decrease rpm.

• Hold the throttle control plate and tighten cap screws.

CAUTION

4/23/97

3 - 19

TESTS AND ADJUSTMENTS

ENGINE

SLOW IDLE SPEED ADJUSTMENT NON CARB/EPA (EARLY MODELS)

Reason:

To set engine slow idle mixture and rpm.

Equipment:

• JTO5719 Photo Tachometer

Procedure:

1. Move transaxle to neutral. Engage park brake.

Slow Idle Stop Screw

Slow Idle Mixture Screw

M55907

NOTE: It may be necessary to adjust slow idle stop

screw again.

11. Recheck slow idle stop screw setting.

Specifications:

SLOW idle stop screw setting. . . . . . 1650 ± 75 rpm

NOTE: For high altitude operation (above 4000 feet),

use high altitude carburetor kit, service part number AM119687 (1994 and above) to prevent over rich fuel mixture and black exhaust smoke.

Standard Carburetors—Non CARB/EPA

2. Put reflective tape on outer rim of blower housing screen.

IMPORTANT: DO NOT force the SLOW idle mixture

screw tight, this will damage the needle and seat. Air cleaner assembly removed for photo clarity, DO NOT remove for tests.

3. While engine is OFF, turn SLOW idle mixture screw

clockwise (in) until lightly seated, then turn counterclockwise (back-out) one full turn.

4. Start and run engine at MEDIUM idle for 5 minutes to obtain operating temperature.

5. Move throttle lever to SLOW idle position.

6. Use a photo tachometer to check engine rpm at the blower housing screen reflective timing tape.

7. Turn SLOW idle stop screw in either direction until specified reached.

8. Turn slow idle mixture screw

(back-out) until engine speed drops off (rich mixture)

point.

9. Turn slow idle mixture screw

engine speed increases and then drops off (lean mixture)

drop-off point.

10. Turn slow idle mixture screw

(back-out) until midpoint (1/8 to 1/4 turn) between rich and lean rpm drop-off points

reached.

SLOW idle speed of 1650 ± 75 rpm

counterclockwise

—Note position of screw at rpm drop-off

clockwise (in) until

—Note position of screw at rpm

counterclockwise

3 - 20

4/23/97

ENGINE

TESTS AND ADJUSTMENTS

SLOW IDLE SPEED ADJUSTMENT —CARB/EPA STX38 (SN 210001— ) & STX46

DO NOT attempt to adjust carburetors that meet California Air Resource Board/Environmental Protection Agency (CARB/EPA) restrictions unless you are a factory trained technician with authorization to service CARB/EPA Emissions Carburetors. These carburetors can be identified by the black limiter on the slow idle mixture screw.

Reason:

To set engine slow idle mixture and rpm.

Equipment:

• JTO5719 Photo Tachometer

Procedure:

1. Move transaxle to neutral. Engage park brake.

ATTENTION

3. Start and run engine at MEDIUM idle for 5 minutes to obtain operating temperature.

4. Move throttle lever to SLOW idle position.

5. Use a photo tachometer to check engine rpm at the blower housing screen reflective timing tape.

6. Turn

NOTE: It may be necessary to adjust slow idle stop

7. Recheck slow idle stop screw setting.

Specifications:

SLOW idle stop screw setting. . . . . . 1650 ± 75 rpm

NOTE: For high altitude operation (above 4000 feet),

Black Limiter

direction until specified

± 75 rpm

is reached.

screw again.

use high altitude carburetor kit, service part number AM119687 (1994 and above) to prevent over rich fuel mixture and black exhaust smoke.

SLOW idle stop screw in either

SLOW idle speed of 1650

Slow Idle Stop Screw

Black Limiter Slow Idle Mixture Screw

M58370

Late Model Carburetors—CARB/EPA

IMPORTANT: DO NOT force the SLOW idle mixture

screw tight, this will damage the needle and seat.

2. Put reflective tape on blower housing screen.

NOTE: On CARB/EPA carburetors, no preliminary

adjustment is required for black limiter slow idle mixture screw, this is pre-set by manufacturer.

4/23/97

3 - 21

TESTS AND ADJUSTMENTS

ENGINE

CYLINDER COMPRESSION TEST

Reason:

To check pressure capacity of piston rings and cylinder bore for efficient engine operation.

IMPORTANT: On engines equipped with an

automatic compression release (ACR) mechanism, a compression test will indicate the ACR compression, not actual compression. A compression test does not provide an adequate method to diagnose the condition of the rings and valves. A cylinder leakdown test is the best method to determine the condition of the rings and valves. By pressurizing the combustion chamber from an external source, you can determine if the valves or rings are leaking.

Equipment:

• JT-03502 Cylinder Leakdown Test Kit —ACR engines only

• JDM-59 Compression Gauge

• JDM-74A-5 Spark Plug Ground Tool

Connections:

1. Move transaxle shift lever to neutral. Engage park brake.

Procedure:

1. Move the throttle lever to FAST idle position.

2. Crank engine and record compression reading.

Specifications:

Minimum Compression . . . . . . . . . 345 kPa (50 psi).

Normal Compression. . . . . . . . . . . 550 kPa (80 psi).

Results:

• If compression is low, put clean engine oil on piston rings through spark plug hole. Repeat cylinder compression test.

• IF COMPRESSION PRESSURE INCREASES: check rings, piston and cylinder bore for broken rings, scoring, wear, or damage. Replace as necessary.

• IF COMPRESSION PRESSURE IS STILL LOW: check for leaking intake or exhaust valves, valve seal, or cylinder head gasket. Replace as necessary.

AUTOMATIC COMPRESSION RELEASE (ACR) TEST

Reason:

To determine if the automatic compression release is opening the exhaust valve.

Equipment:

• Dial Indicator

Procedure:

1. Remove valve cover and spark plug. Rotate crankshaft slowly to observe ACR operation.

M55936

Engine components are HOT. DO NOT touch with bare skin, especially the exhaust pipe or muffler while making test. Wear protective eye glasses and clothing.

IMPORTANT: Spark plug wire must be grounded

or electronic ignition could be damaged.

2. Disconnect and ground spark plug wire.

3. Remove spark plug and install JDM-59 Compression Gauge.

CAUTION

M55859

2. The exhaust valve (A) must open (depress) briefly just after the intake valve closes.

3. Use a dial indicator to measure exhaust valve ACR movement.

4. Install rocker cover, see Remove and Install Cylinder Head in the this section.

Specifications: Exhaust valve ACR movement

Minimum . . . . . . . . . . . . . . . . . . 0.25 mm (0.01 in.)

Results:

• If the exhaust valve does not open or depress properly, the automatic compression release tab is faulty and camshaft assembly must be replaced.

3 - 22

4/23/97

4/4/97 3 - 23

ENGINE

CRANKCASE VACUUM TEST

TESTS AND ADJUSTMENTS

Reason:

To measure the amount of crankcase vacuum, which ensures the crankcase is not pressurized. A pressurized crankcase will force oil past the seals.

Equipment:

• JTO5697 U-Tube Manometer Kit

Connections:

1. Attach manometer magnets to solid metal surface.

IMPORTANT: Connecting manometer to engine

before starting engine will cause water in the manometer to be drawn into engine crankcase. Do not use more than 3 feet of manometer tubing. If a longer hose is used the manometer readings will be inaccurate. Some engines require a rubber hose (adapter) and hose clamps to fit the dipstick opening while some others require #5 plug to be shortened (cut inhalf horizontally) to obtain a tight seal.

Engine components are HOT. DO NOT touch with bare skin, especially the exhaust pipe or muffler while making test. Wear protective eye glasses and appropriate clothing.

Procedure:

1. Start and run engine at FAST idle to allow engine to reach operating temperature—then move throttle to SLOW idle.

2. Quickly remove engine dipstick and attach hose (using adapter or plug) from manometer to dipstick opening.

3. Tighten hose clamp or make sure plug is sealed properly—Move throttle to FAST idle.

4. Record vacuum reading. The reading is obtained by adding (C) and (D) water movement from “0”. In this case reading should be 4 inches of vacuum (2 inches + 2 inches—C + D).

5. If water movement (C) is below the “0” mark— crankcase is pressurized causing seals to leak oil. Crankcase should have negative pressure.

6. Repeat test at least three times for accuracy. DO NOT shut off engine. To repeat test, remove the manometer tube from top of manometer at valve (A). DO NOT remove manometer tube from engine. Be sure to reset manometer at zero—see step 3. Reattach manometer tube to valve (A) and record reading.

7. Remove line from manometer (valve “A”) before stopping engine. Then remove dipstick hose, adapter or plug connection and install dipstick.

CAUTION

1 0 1 2

M55940

2. Open top valves (A) and (B) one full turn.

2 1 0 1 2

3. Zero out the manometer by sliding the ruled scale up or down so “0” is located where water level is even on both sides.

Results:

Crankcase reading should show a minimum vacuum of 25 mm (1 in.) of water movement. V-twin engines might show less than 25 mm (1 in.) of water movement; this is not a problem, as long as some vacuum is indicated, engine is operating properly. Check the following if reading is less than minimum specification:

• Breather reed valve clearance and condition;

• Seals and gaskets for leakage, including rocker arm cover gasket;

• Valve and valve seats for wear or damage;

• Rings, piston, and cylinder bore for wear or damage.

TESTS AND ADJUSTMENTS

ENGINE

FUEL FLOW TEST

Reason:

To determine fuel availability to the carburetor.

Equipment:

• Proper Fuel Container

Connections:

M55938

1. Clamp fuel line (A) or turn off fuel shut-off valve, if equipped, to prevent fuel flow.

2. Disconnect fuel line (B) from carburetor and place in container.

NOTE: Oil Pressure Test Kit AM122553 has been

replaced with SERVICEGARD Oil Pressure Test Kit JTO7262. This kit includes an oil filter adapter and O-ring only. The hose (JTO3017), gauge (JTO7034), coupler (JTO3262), and fitting (JTO5487) are found in other SERVICEGARD test kits.

Procedure:

1. Park machine on level surface, turn key switch OFF, and allow engine to cool.

2. Check engine oil level, bring level to full mark.

Oil Filter

Drain Plug

M85845

Procedure:

1. Release clamp on fuel line (A) or turn on fuel shutoff valve, if equipped. Fuel should flow freely into container.

2. Clamp line or close valve to install line (B) on carburetor.

3. Pore captured fuel into tank.

Results:

If fuel flow is slow, check the following:

• Replace fuel filter

• Check fuel lines, shut-off valve (if equipped), fuel tank outlet, and fuel tank cap for restrictions

OIL PRESSURE TEST

Reason:

To verify if the engine has enough oil pressure to lubricate internal components.

Test Equipment:

• Oil Pressure Test Kit JTO7262

• Fitting JTO5487

• Gauge JTO7034

• Coupler JTO3262

• Hose JTO3017

Engine components are HOT. DO NOT touch with bare skin, especially the exhaust pipe or muffler while making test. Wear protective eye glasses and clothing.

For Engines With No Oil Pressure Test Port:

3. Remove oil filter. (Plastic bag may be used to protect paint and channel oil to drain pan).

4. Install pressure tester to oil filter flange.

5. Start engine and run until hot. (Be sure to maintain full crankcase oil level during testing).

6. Check oil pressure when oil is both cold and hot, and at both idle and full throttle.

For Engines With Oil Pressure Test Port:

1. Attach Oil Pressure Test Hose to engine by removing plug on housing below oil filter.

2. Install test gauge on test hose.

3. Start engine and run until hot. (Be sure to maintain full crankcase oil level during testing).

4. Check oil pressure when oil is both cold and hot, and at both idle and full throttle.

Results:

• Oil pressure on a cold engine at start-up can reach as high as 414 kPa (60 psi). (Pressure relief valve will open beyond this pressure).

• Oil pressure at operating temperature (warm engine at idle) may be as low as 124 kPa (18 psi).

CAUTION

3 - 24

4/23/97

ENGINE

FUEL AND AIR SYSTEM REPAIR

FUEL TANK AND DASH PANEL COMPONENTS

Dash Panel

Filler Cap With Gauge (Optional)

Filler Cap

Screw

(6 Used)

FUEL AND AIR SYSTEM REPAIR

Clip Nut (2 Used)

LH Heat Shield

Bushing (4 Used)

Hose Clamps (7 Used)

Bulk Hose (Cut-To-Length As Required)

Cap Screw (4 Used)

Bushing (4 Used)

Pedestal

Fastener Grommet (4 Used)

Fuel Tank

Carburetor Hose Fuel

Filter

Fuel Shut-Off Valve

Hose Clamps (7 Used)

RH Heat Shield

Cap Screw

Hose Clamps

Bulk Hose (Cut-To-Length As Required)

Hose Clip (2 Used)

(7 Used)

4/23/97

Flange Nut (4 Used)

Flange Nut

M58321

3 - 25

FUEL AND AIR SYSTEM REPAIR

REMOVE AND INSTALL FUEL TANK AND DASH PANEL ASSEMBLY

ENGINE

1. Disconnect battery ground (-) cable.

CAUTION

M58321

M55905

9. Remove orange tab lever from throttle cable assembly (G) only if dash panel or throttle cable assembly are to be replaced.

10. Remove six screws (F) to separate tank from dash panel and cable assembly (G).

11. Remove overflow tube and fuel line, replace as necessary.

Gasoline is explosive. Do not expose to flame or spark. Serious injury can result. Catch or wipe up any spilled fuel immediately.

2. Squeeze fuel line (C) closed between tank and filter or turn fuel shut-off valve, if equipped, to CLOSED position.

3. Disconnect fuel line at filter (B) or filter side of fuel shut-off valve, if equipped.

4. Remove fill cap and drain any fuel into an approved container.

5. Disconnect throttle cable (A) at throttle plate.

6. Remove right and left side hood latch brackets (D).

7. Remove steering wheel and washer(s) (E).

8. Remove fuel tank/dash panel assembly to workbench.

M58322

12. Remove and replace throttle cable assembly (G) as necessary.

13. Properly dispose of fuel tank and/or dash panel as necessary.

3 - 26

4/23/97

ENGINE

FUEL AND AIR SYSTEM REPAIR

M58320

14. Install overflow tube and fuel line to fuel tank spigots (H) and (J), respectively.

15. Install end of cable assembly (G) through slot (I).

M58323

16. Install fuel tank lip (K) in console notches (L) while aligning six mounting holes.

M58321

17. Fasten fuel tank to dash panel with six screws.

18. Install orange tab lever on end of throttle lever assembly (G).

M58306

19. Align fuel hose with slot (M), over-flow tube with frame hole (N), and dash panel steering shaft hole with steering shaft (O) as you install fuel tank/dash panel assembly onto steering pedestal.

4/23/97

3 - 27

FUEL AND AIR SYSTEM REPAIR

ENGINE

REPLACE FUEL FILTER

Keep cigarettes, sparks, and flames away from fuel system. Make sure engine is cool to touch.

CAUTION

20. Install left and right side hood latch brackets (E) removed earlier.

21. Connect fuel line (C) to filter (B) or fuel shut-off valve (D), if equipped, to fuel line (C).

NOTE: Apply John Deere NEVER-SEEZ® lubricant to

steering shaft before installing steering wheel.

22. Install washer(s) exactly as removed earlier onto steering shaft.

23. Install steering wheel and fasten with cap screw and lock nut.

24. Add fuel to tank and turn fuel shut-off valve (if equipped) to ON position or release pinch device.

25. Check for and fix any leaks.

M58326

1. Pinch fuel line (B) between tank and filter to block fuel flow or turn fuel shut-off valve, if equipped, to

OFF position.

2. Slide filter clamps (C) back to disconnect hoses from filter.

3. Install new filter with arrow (A) pointing towards carburetor.

4. Clamp filter in place with two clamps (C).

5. Remove pinch device on fuel line or turn fuel shutoff valve, if equipped, to ON position.

6. Fill tank. Check for and fix any leaks.

M55813

1. NEVER-SEEZ is a trademark of the Emhart Chemical Corporation.

3 - 28

4/23/97

ENGINE

AIR INTAKE SYSTEM COMPONENTS

FUEL AND AIR SYSTEM REPAIR

Knob

Gasket

IMPORTANT: Grommet must be in place to prevent

dirt ingestion. Late model tractors have outer foam air filter element (pre-cleaner) and a different cover and base design.

Stud

Shield

Gasket

Stud Retaining Screw

Use Thread-Lock and Sealer

Gasket

Remove studs to remove carburetor

Sleeve

Stud

Washer

Used on stud without electrical eyelet of grounding lead

Cover

Air Cleaner

Housing

Nut

Tighten to 10 N•m (88 lb-in.)

Wing Nut

Washer Grommet

Foam Element

Paper Element

M55326

REMOVE AND INSTALL CARBURETOR

M55908

Gasoline is explosive. Do not expose to flame or spark. Serious injury can result.

1. Turn key switch OFF and disconnect battery

negative (-) ground cable.

2. Pinch fuel line (B) to block fuel flow or turn fuel shut-

off valve (if equipped) to OFF position, then disconnect fuel line and solenoid wire (D) (if optional fuel shut-off solenoid is installed).

3. Remove air filter assembly (not shown) and

carburetor, DO NOT damage threads of studs (C).

4. Disconnect linkage rods (A) from carburetor levers.

5. Remove and discard gaskets (E), install new ones.

6. Connect linkage rods (A) and install carburetor,

studs (C), and air filter assembly.

7. Connect solenoid wire (D) (if installed), and fuel line

(B)—open fuel line or turn fuel shut-off valve ( if installed) to ON position.

8. Adjust carburetor, see Test and Adjustments earlier

in this section.

CAUTION

4/23/97

Specification:

Air Filter Assembly Nuts . . . . . . . 10 N•m (88 lb-in.)

3 - 29

FUEL AND AIR SYSTEM REPAIR

M58370

ENGINE

INSPECT CARBURETOR

Gasoline is explosive. Do not expose to flame or spark. Serious injury can result. DO NOT expose them to flame or spark. Follow the cleaner manufacture’s warnings and instructions on its proper and safe use. Never use gasoline as a cleaning agent.

Throttle Shaft

Throttle Plate

Idle Screw

Fuel Screw

Main Jet

Float

CAUTION

Choke Shaft

Seal

Choke Spring

Body

Choke Plate

Inlet Seal

Needle

4. If inlet seat was leaking or damaged it can be replaced by pulling it out with a drill bit or screw. Always replace with new parts. Press in new seat until it bottoms in bore.

5. If throttle and choke plates were removed, use a high strength thread lock and sealer on the small retaining screws. Install screws slightly loose. Apply pressure on shafts to center plates in bore, then tighten screws.

IMPORTANT: STX38 Serial Numbers

(STXH271285—272591 Gear) (STXJ270811—272392 Hydro)—Float may stick in carburetor bowl due to main jet not being flush with carburetor body, this can cause fuel in crankcase and exhaust. Inspect and repair carburetor main jet as required. Removal of carburetor is not necessary. You will be able to feel the jet with your finger, or visibly see it, if it is not completely pressed in. If main jet is not completely flush, press jet flush to carburetor body using a flat blade screwdriver and pliers.

6. Main jet can be pressed out. Replace with new jet (high altitude jet is available). Press new jet in until flush with surface.

7. Low idle mixture screw has a precision taper. If screw is grooved, bent or broken this may indicate seat damage and carburetor may need to be replaced.

8. On standard carburetors, to set preliminary adjustment for idle mixture screw—

clockwise until LIGHTLY seated and back-out (counterclockwise) one full turn

turn

Float Bowl

Fuel Shut-Off

Solenoid

Optional

1. Disassemble bowl, float, inlet needle, low idle mixture screw and spring.

IMPORTANT: Further disassembly of carburetor is

not required for general cleaning. Further disassembly will require replacing parts with new parts. DO NOT soak carburetor in carburetor cleaner when fiber, rubber or foam gaskets are still installed. Cleaner may damage these components.

2. Clean carburetor using pressurized carburetor cleaner and compressed air. Clean out all passages.

3. DO NOT remove idle port welch plug unless absolutely necessary. To remove, pierce with sharp tool. Clean chamber. Install new plug using a flat tool about the same size as plug. Flatten plug but do not force below the surface of the cavity.

M52127

CARB/EPA Carburetor

9. On CARB/EPA carburetors, no preliminary adjustment is required for idle mixture screw (A), this is pre-set by manufacturer—

(limited to maximum 1/4 turn in either direction) until specified slow idle speed is obtained (see Slow Idle Speed Adjustment, earlier in Tests and Adjustments group of this section)

Specifications: Carburetor Float Bowl Cap Screw . 6 N•m (55 lb-in.)

only turn screw

3 - 30

4/23/97

ENGINE

prop

REPAIR

REMOVE AND INSTALL ENGINE

1. Turn all switches OFF and disconnect battery negative (-) cable.

M55812

2. Raise hood to disconnect springs (A) from mounting brackets on front tractor frame.

3. Lower hood and pull forward to remove.

Gasoline is explosive. Do not expose to flame or

ark. Serious injury can result. Store in a

erly marked, safe container. Wipe-up an

spills IMMEDIATELY.

7. Disconnect fuel line (E) at carburetor to drain fuel. Disconnect harness connector (G).

8. Disconnect wires from starter terminal (J).

9. Remove shield (L) and muffler (K).

10. Remove PTO clutch (see Remove and Install PTO Clutch in Electrical Section).

CAUTION

M55814

M55908

4. Disconnect optional fuel shut-off solenoid wire (D), if installed and cut tie straps (B) to separate yellow lead (C) from engine. Air filter assembly removed for clarity purposes only.

M58326

5. Turn fuel shut-off valve (F) to OFF position or pinch hose (E) close to carburetor.

6. Loosen clamp (H) to disconnect throttle cable (I).

M55799

11. Remove four cap screws (M), 3 washers and disconnect ground lead (N), then remove engine.

12. Install engine and ground lead (N), as shown. Use medium strength thread lock and sealer. Tighten four cap screws (M) (use 1 washer per cap screw except ground cable cap screw) to specification.

13. Install muffler, new gasket, and shield. Tighten muffler nuts to specification.

14. Install PTO clutch (see Remove and Install PTO Clutch in Electrical Section).

15. Make all electrical wiring connections, including battery (negative cable last).

16. Connect and adjust throttle cable (see Tests and Adjustments, earlier in this section).

17. Connect fuel line and adjust carburetor (see Tests and Adjustments, earlier in this section).

Specifications: Engine Cap Screws

. . . . . . . . . . . . . . . . . 27—46 N•m (240—408 lb-in.)

Muffler Mounting Nuts

. . . . . . . .

24 N•m (216 lb-in.)

4/23/97

3 - 31

REPAIR

REMOVE AND INSTALL ROCKER ARMS

1. Remove valve cover.

ENGINE

Late model shown Early model differs slightly

M55859

IMPORTANT: Mark push rods for assembly in

original locations.

2. Remove cap screws (C) and pivot ball spacers (B).

3. Remove rocker arms (D).

4. Remove push rods (E).

5. Remove splash plate (A).

6. Inspect and replace components as necessary.

7. Install components in reverse order of removal.

Specification:

Rocker Pivot Bolts. . . . . . . . . . . . 14 N•m (124 lb-in.)

INSPECT PUSH ROD

M55861

1. Remove cap screws (A), spacer (B) and cylinder head. Discard gasket and clean head and block.

2. Install new gasket with cylinder head, cap screws and spacer.

M52074

3. Torque cylinder head cap screws in 7 N•m (62 lbin.) increments in sequence illustrated.

Specification: Push Rod Bend (maximum) . . . 0.76 mm (0.030 in.)

REMOVE AND INSTALL CYLINDER HEAD

IMPORTANT: Engine must be cold before

removing cap screws to avoid warping aluminum cylinder head.

NOTE: Cylinder head can be serviced without

removing engine from tractor.

3 - 32

Specification:

Cylinder Head Cap Screws . . . . . . .41 N•m (30 lb-ft)

4. Install push rods and rocker arms.

M52075

5. Clean valve cover and install using RTV silicone sealant between mating surfaces. Tighten valve cover cap screws, in sequence illustrated.

Specification:

Valve Cover Cap Screws. . . . . . . 7.4 N•m (65 lb-in.)

4/23/97

ENGINE

REMOVE AND INSTALL VALVES AND SPRINGS

REPAIR

M55867

IMPORTANT: Make sure keepers are seated in

valve stem groove (D).

1. Compress intake and exhaust springs using an appropriate size spring compressor.

2. Remove keepers (C), spring caps (B), springs (A), and valves (E).

IMPORTANT: STX38 (SN 210000— ) intake valve

seal is not required.

M52080

3. Put head on a

surface plate. Check for

flat

distortion at several points with a feeler gauge. Replace head if distorted beyond specification.

Specification: Cylinder Head Distortion (maximum)

. . . . . . . . . . . . . . . . . . . . . . . . . . 0.076 mm (0.003 in.)

INSPECT VALVES

1. Remove carbon from valve head, face, and stem.

2. Check valve for cracks or damage.

3. Install valve components.

4. Compress spring and install keepers in grooves (D).

5. Install rocker arm assembly and cylinder head in reverse order.

INSPECT CYLINDER HEAD

1. Remove carbon deposits and clean gasket surface with SCOTCH-BRITE®

2. Inspect head for cracks or damage. Make sure oil drain port is open.

1. SCOTCH-BRITE is a registered trademark of the 3M Compan

4/23/97

abrasive or equivalent.

M38087

3. Replace warped valves (A) or valves with less than serviceable margin (B). Valve stem ends (C) should be square, not worn uneven as shown.

M51753

4. Inspect valve stems for bends using V-blocks and dial indicator. Turn valve slowly and read variation. Replace if variation is greater than specification.

Specification: Valve Stem Bend (maximum)

. . . . . . . . . . . . . . . . . . . . . . . . 0.076 mm (0.003 in.)

3 - 33

REPAIR

ANALYZE VALVES

ENGINE

M29934

Lead deposits on the intake valve are caused by exhaust gas leakage past the valve when using leaded gasoline. Grind intake valve and reface valve seat to correct this condition.

Use unleaded fuel to prevent lead deposits.

M55630

Valve stem corrosion is caused by moisture in the engine which occurs during hot engine cool-down periods or during storage.

Fogging of combustion chamber with oil before storage helps prevent corrosion. Replace badly corroded valves.

M29936

Use of old or stale gasoline can cause valves to stick. Gummy deposits (C) can build up on valve and can

also gum carburetor, requiring cleaning. Always use fresh gasoline of 87 octane rating or

higher. Drain fuel tank, lines, and carburetor before storage.

M30024

Operating at high temperatures for long periods of time can cause exhaust valve burning. Burned valve will show dark discoloration into the area protected by the valve guide. Another indication is distortion of the margin (A) and face angle (B). The valve seat may also show erosion.

An overheated engine can also cause valve burning. Check for clogged engine cooling fins. Do not run engine with blower housing removed. Also check for worn valve guides, springs or hydraulic lifters, lean fuel-air mixture, or incorrect spark plug.

3 - 34

4/23/97

ENGINE

REPAIR

INSPECT VALVE GUIDES

1. Clean inside of valve guide. Standard valve guide reamer (D20020WI) can be used.

M52081

2. Measure inside diameter of guide with gauge (A).

RECONDITION VALVE SEATS

1.5

Exhaust Valve

6.970/6.988

6.5

7.033/

7.058

7.033/

7.058

31.63/

31.37

45°

Exhaust Insert

34.013/

33.987

89°

Intake Insert

89°

M52082

3. Measure outside diameter of valve stem (B).

4. An oversize valve is available. Replace valve if stem-to-guide clearance is too great.

IMPORTANT: If guide is reamed oversized, an

oversize valve must be installed.

5. Use oversize reaming tool (JDG705) to ream guide, if necessary.

6. Replace cylinder head if inside diameter of guide is greater than oversize specification.

Specifications: Valve Guide Ream (standard)

. . . . . . . . . . . . . . . . . . . . . . . . . 7.048 mm (0.2775 in.)

Valve Guide Ream (oversize)

. . . . . . . . . . . . . . . . . . . . . . . . . 7.298 mm (0.2873 in.)

Intake Stem-to-Guide Clearance

. . . . . . . . . . . . .0.38—0.076 mm (0.0015—0.0030 in.)

Intake Guide (Maximum Wear)

. . . . . . . . . . . . . . . . . . . . . . . . . 7.134 mm (0.2809 in.)

Exhaust Stem-to-Guide Clearance

. . . . . . . . . . . . .0.050—0.088 mm (0.002—0.0035 in.)

Exhaust Guide (Maximum Wear)

. . . . . . . . . . . . . . . . . . . . . . . . . 7.159 mm (0.2819 in.)

45°

35.63/

35.37

Intake Valve

6.982/7.000

1.5

37.987/

38.013

89°

M55939

1. Inspect valve seats.

2. Replace cylinder head if seats are warped or distorted beyond reconditioning.

3. Reface pitted or worn seats as shown in drawing.

4. Lap valves after refacing

5. Check seat for good contact using Prussian Blue Compound.

4/23/97

3 - 35

REPAIR

LAP VALVES

ENGINE

IMPORTANT: Valves and seats should be lapped if

they do not make good contact.

M52134

1. Apply light coat of lapping compound to valve face, then turn valve in seat using vacuum cup tool.

2. Check valve every 8 strokes until a uniform ring appears around surface of valve face.

3. Wash parts in solvent to remove lapping compound.

4. Check position of lap mark on face–lap mark must be on or near center of valve face.

INSPECT BREATHER

M52084

3. Hold flywheel with strap wrench. Remove cap screw (C).

M52085

M55868

1. Remove cap screw (A), plate (B), and reed (C).

2. Check that breather opening is clear.

3. Replace reed if it does not lie flat on casting.

4. Clean mating surface of any sealant residue (D).

REMOVE AND INSTALL FLYWHEEL

1. Remove blower housing sheet metal.

4. Remove flywheel using a puller.

NOTE: Flywheel and magnets are not serviceable.

5. Inspect flywheel for cracks, chips, and broken teeth. Replace as necessary.

6. Inspect for sheared or partially sheared key, replace as necessary.

IMPORTANT: Check that crankshaft end and

flywheel hub are clean and free of lubricant, and flywheel key is installed properly in keyway. Improperly installed flywheel can cause machine damage and serious personal injury.

7. Install flywheel and key on crankshaft.

8. Hold flywheel with strap wrench. Tighten cap screw (A) to specification.

9. Check ignition module air gap (see Adjust Ignition Module Air Gap, in the Tests and Adjustments Group of the Electrical Section).

M52083

2. Remove four fan cap screws and washers (B) and fan (A

3 - 36

Specification:

Flywheel Cap Screw. . . . . . . . . . . . 68 N•m (50 lb-ft).

4/23/97

ENGINE

(

)

REPAIR

REMOVE AND INSTALL CAMSHAFT

M55873

1. Rotate crankshaft to align two sets of marks (A).

2. Remove camshaft (B).

3. Inspect camshaft closely, replace as necessary.

4. Coat entire camshaft with engine oil.

5. Install camshaft with four timing marks (A) aligned.

6. Check camshaft end play.

7. If not within specification, use appropriate shims from Camshaft Shim Kit (D), shown below in photo M58327.

8. Align flat surface of balancer shaft with bore flat of oil pump inner rotor gear as you install oil pan.

9. Install push rods, rocker arm assembly, and valve cover, see those procedures earlier in this section.

3. Inspect lobes (B). Replace camshaft if lobes show excessive wear.

4. Inspect ACR mechanism (C). Replace spring if necessary and check that weight moves freely.

M52091

5. Measure camshaft bore (E) in oil pan.

6. Subtract journal OD. from bore ID. to determine clearance with camshaft journal. Replace if not within specifications.

Camshaft Bearing Bore Specification: Oil Pan Camshaft Bore

(New) . . . . . 20.000—20.025 mm (0.7874—0.7844 in.)

Max. Wear Limit

Camshaft

to Bore

. . . . . . . . . 20.038 mm (0.7889 in.)

Clearance . . . 0.025—0.063 mm (0.0010—0.0025 in.)

Specification: Camshaft End Play

. . . . . . . . . . . . . 0.076–0.127 mm (0.003–0.005 in.)

INSPECT CAMSHAFT

Steel Gear

Camshaft

M58327

1. Inspect camshaft for worn or broken teeth.

2. Measure journals (A). Replace camshaft if measurements do not meet specifications.

Plastic Gear

Camshaft

M52092

7. Measure camshaft bore (F) in crankcase.

8. Subtract journal OD. from bore ID. to determine clearance with camshaft journal. Replace if not within specification.

Camshaft Bearing Bore Specification: Crankcase Camshaft Bore

(New) . . . . . 20.000—20.025 mm (0.7874—0.7844 in.)

(Max. Wear Limit) . . . . . . . . . 20.038 mm (0.7889 in.)

Camshaft to Bore Clearance . . . 0.025—0.063 mm (0.0010—0.0025 in.)

Camshaft Journal Specification: O.D. (New)

. . . . . . . .19.962—19.975 mm (0.7859—0.7864 in.)

O.D. (Max. Wear Limit). . . . . 19.959 mm (0.7858 in.)

4/23/97

3 - 37

REPAIR

ENGINE

MEASURE CAMSHAFT END PLAY

1. Check that camshaft is seated in crankcase bore.

M52093

2. Measure play (A) between camshaft and straight edge (spanning crankcase) using flat feeler gauge.

3. Use shims from Shim Kit as necessary until end play is within specification.

Camshaft End Play Specification (with shims):

(Maximum). . . . 0.076—0.127 mm(0.003—0.005 in.)

Shim Thickness Range: The most commonly used shims are listed below.

Additional shims are available through the parts catalogue.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.73 mm (0.29 in.)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.75 mm (0.30 in.)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.81 mm (0.32 in.)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.86 mm (0.34 in.)

HYDRAULIC VALVE LIFTERS— INSPECTION

Reasons:

• If lifter noise continues after 20 minutes of running, it is probably an indication of contamination or dirt in the lifter preventing the check ball from seating. Replace lifter.

• A lifter which suddenly gets noisy while engine is running would probably be caused by trapped. If noise is caused by contamination, replace lifter. If noise is caused by trapped air, see Step 2 under “Lifter Noise After Start-Up”.

• Lifter noise which appears or worsens as the engine heats up is usually due to wear in the lifters and other engine components, especially if engine has considerable running hours or has not had regular oil changes. Replaces lifters and other internal engine components that do not meet wear limit specifications.

• A situation where the lifter seems to pump up too much, holds a valve open, causes loss of compression or hard starting, indicates insufficient clearance between the plunger and body. Replace lifter.

IMPORTANT: Damaged or worn lifters usually

indicate a damaged camshaft. Check camshaft before replacing lifters.

HYDRAULIC VALVE LIFTERS— REMOVE AND INSTALL

1. Remove camshaft.

IMPORTANT: Used lifters are mated to their

camshaft lobes. Mark them for installation in the correct bore.

M52094

2. Remove lifters (A).

3. Inspect lifters for wear, replace as necessary.

4. Coat lifters with engine oil and install in correct bore.

5. Install camshaft.

M52095

1. Inspect lifter face (B) for wear. Face should be flat and smooth.

2. Use push rod to depress plunger (A). Plunger should offer resistance but move smoothly.

3. Check that oil hole (C) is clear to inner piston.

4. Measure outside diameter of lifter.

3 - 38

4/23/97

ENGINE

M52097

REPAIR

5. If engine does not turn over completely (locks up at some point), stop turning at the point of lockup and allow 10 more minutes for the lifters to bleed down. Then try rotating by hand again.

Results

• Lifter noise immediately after start-up is usually due to contraction and/or leakdown. There will be some noise when engine is first started but should last only a few seconds, but no more than a few minutes.

• If lifter is still noisy after 5 minutes of running, air could be trapped in the lifter. Stop engine and check oil level. Adjust as necessary and run engine for an additional 20 minutes at half throttle.

5. Measure inside diameter of crankcase lifter bore (D).

6. Subtract lifter OD. from bore ID. to determine if clearance is not within specification.

IMPORTANT: Make sure lifters are “PRIMED”

before installation and “BLED” before start up to prevent damage to push rods or rocker arms. See priming and bleeding procedure on page 3-

41.

7. Replace lifters that are worn or damaged. Replace components as necessary.

Specification: Valve Lifter To Bore Clearance (maximum)

. . . . . . . .0.0124—0.0501 mm (0.0005—0.0020 in.)

Priming Procedure For Hydraulic Lifters

1. Place lifter in small container.

2. Pour 10W30 oil into container until oil is level with top of lifter.

3. Place the end of one of the push rods into the socket on top of the lifter and “pump” the lifter with push rod until it feels solid.

4. Remove lifter from oil, let it drip off for a moment, and install into appropriate bore in engine.

BALANCER SHAFT REMOVAL & INSTALLATION

1. Align marks (A) on balancer shaft and crankshaft.

2. Remove balancer shaft (B).

3. Inspect balancer shaft, replace as necessary.

4. Align marks (A) and install balancer shaft (B) so it also aligns with governor gear (C).

5. Remember, when installing oil pan, be sure to align flat (D) of balancer shaft with bore flat of oil pump inner rotor gear.

M52099

Bleed Procedure For Hydraulic Lifters

1. After installing cylinder head, rotate flywheel so piston is at TDC (top-dead-center) between the exhaust and intake strokes. At TDC, the rocker arms will move alternately if the flywheel is rocked. This allows for maximum pressure on the lifters.

2. Leave engine in this position and re-assemble remaining engine parts.

3. After engine has been in this position for 10 minutes (can include assembly time) turn engine over slowly by hand.

4. If engine turns over completely, fill the crankcase to proper level with recommended oil and test run.

4/23/97

3 - 39

REPAIR

BALANCER SHAFT INSPECTION

ENGINE

M52100

1. Inspect shaft for cracks and broken teeth. Replace shaft if cracked or damaged.

2. Measure journals (A). Replace if not within specification.

Balancer Shaft Journal O. D. Specification

New . . . . . . 19.962—19.975 mm (0.7859—0.7864 in.)

Wear Limit. . . . . . . . . . . . . . . 19.959 mm (0.7858 in.)

M52101

3. Measure balancer shaft bore (B) in crankcase.

4. Subtract journal OD. from bore ID. to determine clearance with balancer shaft journal. Replace crankcase if measurements are not within specifications.

Balancer Shaft Crankcase Bore Specifications: ID (New)

. . . . . . . .20.000—20.025 mm (0.7874—0.7884 in.)

Wear Limit. . . . . . . . . . . . . . . 19.959 mm (0.7858 in.)

Balancer Shaft to Crankcase Bore Clearance

. . . . . . . . . .0.025—0.063 mm (0.0009—0.0025 in.)

M52102

5. Measure balancer shaft bore (C) in oil pan.

6. Determine clearance with balancer shaft journal. Replace oil pan if measurements not within specifications.

Balancer Shaft Oil Pan Bore Specifications: ID (New). . .20.000—20.025 mm (0.7874—0.7884 in.)

Wear Limit. . . . . . . . . . . . . . . 19.959 mm (0.7858 in.)

Balancer Shaft to Crankcase Bore Clearance

. . . . . . . . . . . .0.025—0.063 mm (0.0009—0.0025 in.)

GOVERNOR REMOVAL & INSTALLATION

1. Remove governor lever (not shown) from end of control arm (E).

2. Remove spring clip (F), washers (C), and governor control arm (A) from inside of crankcase.

3. Remove and discard seal (D).

M52104

NOTE: Check governor shaft/gear assembly, if plastic

gear, flyweight assembly, flyweight cap, and/or shaft are damaged, the complete assembly must be replaced.

4. Inspect governor shaft/gear assembly (B), replace as necessary (see Replace Governor Shaft/Gear Assembly, later in this group).

5. Install governor shaft/gear assembly.

6. Install new seal (D) using suitable driver.

7. Install control arm, washers, and clip.

8. Install lever (not shown).

3 - 40

4/23/97

ENGINE

GOVERNOR INSPECTION

Inside of Crankcase

REPAIR

To Remove

Shaft

M42195

M52105

1. Measure outside diameter of control arm shaft. Replace if not within specification.

Governor Control Arm Specifications: O.D. (New). . . 5.975—6.000 mm (0.2352—0.2362 in.)

Wear Limit. . . . . . . . . . . . . . . . 5.962 mm (0.2347 in.)

M52106

2. Measure inside diameter of crankcase bore (A).

Governor Control Arm Crankcase Bore Specs:

I.D. (New). . . . 6.025—6.050 mm (0.2372—0.2382 in.)

Wear Limit. . . . . . . . . . . . . . . . 6.063 mm (0.2387 in.)

3. Determine governor control arm shaft-to- bore clearance. Replace governor shaft/gear assembly as necessary.

Governor Control Arm-to-Crankcase Bore Specs: Clearance . . . 0.025—0.075 mm (0.0010—0.0030 in.)

4. Inspect flyweights (B) for proper operation and free movement. Replace governor shaft/gear assembly as necessary.

5. With a small punch, CAREFULLY drive governor shaft toward inside of crankcase to remove it.

6. From inside of crankcase, install new governor shaft/gear assembly by pressing or lightly tapping shaft into crankcase bore to specified height (C).

Governor Gear Shaft Specifications: Height (C)

. . . . . . . . . .32.639—32.842 mm (1.285—1.293 in.)

Diameter (New)

. . . . . . . . . . 5.990—6.000 mm (0.2358—0.2362 in.

Diameter (Wear Limit)

. . . . . . . . . . . . . . . . . . . . . . . . 5.977mm (0.2353 in.)

REMOVE PISTON ASSEMBLY

1. Remove balance shaft, and camshaft.

IMPORTANT: Remove carbon ridge, if present,

from cylinder before removing piston.

2. Remove carbon ridge, if present at top of cylinder, using a ridge reamer.

IMPORTANT: DO NOT remove governor shaft with

vise-grips or pliers, damage to case may result.

4/23/97

M55875

3. Remove cap screws (A) to remove cap (B) from connecting rod (C).

4. Remove piston assembly through top of cylinder.

5. Inspect piston assembly, see following two topics.

3 - 41

REPAIR

(C)

(A)

ENGINE

ANALYZE PISTON RING WEAR

Rings of the wrong size or rings having improper end

ap will not conform to the shape of the cylinder. This

results in hi

end gaps should be staggered on the piston

Rin durin cause oil consumption and blowb

ht scuffing or scoring (A) of both rings and piston occurs when unusuall temperatures approach the meltin material.

When this condition exists, it is due to one or more of the followin

1. Dirty cooling shroud and cylinder head.

2. Lack of cylinder lubrication.

3. Improper combustion.

4. Wrong bearing or piston clearance.

5. Too much oil in crankcase causing fluid friction.

h oil consumption and excessive blowby.

installation. End gaps in alignment can also

M29943

high friction and combustion

point of the piston

probable causes:

Vertical scratches due to an abrasive in the en airborne, ma

have been left in the engine durin

across the piston and rings are

ine. Abrasives may be

overhaul or may be loose lead and carbon deposits. When this condition exists, check for one or more of

the followin

1. Damaged, collapsed, or improperly installed air filter.

2. Loose connection or damaged gasket between air cleaner and carburetor.

3. Air leak around carburetor-to-cylinder block gasket.

4. Air leakage around throttle shaft.

5. Failure to properly clean cylinder bore after reconditioning engine.

M38101

Abrasive particles in en rails control rin

of oil control ring. If inner spacer (B) of oil

is worn or distorted it may cause:

• Increased or hi

h oil consumption.

ine oil cause scratches on side

• Increased deposits in combustion chamber.

• Stickin

compression rings.

M29944

The en ma form in the piston

ine operating at abnormally high temperatures

cause varnish, lacquer, or carbon deposits (B) to

rooves making the rings stick. When this happens, excessive oil consumption and blowb

En b

will occur.

ine overheating and ring sticking is usually caused

one or more of the following:

1. Overloading.

2. Incorrect ignition timing.

3. Lean fuel mixture.

4. Dirty cooling fins.

5. Incorrect oil.

6. Low oil supply.

7. Stale fuel.

ANALYZE PISTON WEAR

DETONATION—

Detonation is uncontrolled combustion excessive temperature and pressure in the combustion chamber. Commonl knock, or timin extremel

nites spontaneously—causing a second burn point

i durin

hot, over-compressed, fuel-air mixture

the normal ignition cycle. This second burn then collides with the spark plu loud explosion and extreme shockwave.

M58335

caused b

called carbon knock, spark

knock; detonation occurs when the

induced burn (B), causing a

3 - 42

4/23/97

ENGINE

(D)

(A)

REPAIR

IMPROPER ROD AND PISTON ALIGNMENT—

M29947

This detonation shockwave (“hammering”) of the piston inside the c top rin locks

The followin

linder causes damage to piston crown (C),

and groove (F), piston side skirts (E), and pin

is a list of possible causes for detonation:

1. Lean fuel mixture.

2. Low octane fuel.

3. Advanced ignition timing.

4. Engine lugging.

5. Buildup of carbon deposits on piston or cylinder head, causing excessive compression.

6. Wrong cylinder head or excessive milling of head increasing compression ratio.

PRE-IGNITION—

Check rod and piston ali

onal wear pattern (A) extending across the skirt of

dia the piston. Contact with the c bottom of skirt at left and rin

nment when piston shows a

linder wall shows on

lands on the right (B).

CYLINDER BORED IMPROPERLY—

M29948

nition is the igniting of the fuel-air mixture prior to

Pre-i proper i shock, resultin Severe dama rin

Check the followin

nition spark. Pre-ignition causes internal

in pings, vibration, and power loss.

e is caused to the piston crown (A),

s, and valves results from pre-ignition.

for causes of pre-ignition:

1. Hot internal carbon deposits.

2. Incorrect spark plug (high heat range).

3. Broken ceramic insulation of spark plug.

4. Hot sharp edges on valves.

M30039

M29949

A c

linder bored at an angle to the crankshaft ma

result in improper ring contact with the cylinder which

cause the following:

1. Rapid and uneven piston ring wear.

2. Rapid and uneven piston wear.

3. Loose or broken piston pin retaining rings.

4. Excessive oil consumption.

A broken piston pin retainin

ring caused the damage

shown. Piston pin retaining rings loosen or break

due to:

1. Rod misalignment.

2. Excessive crankshaft end play.

3. Crankshaft journal taper.

4. Weak piston pin retaining rings.

5. Incorrectly installed piston pin retaining rings.

Inertia can also cause a broken piston pin retainin

rin to beat out the piston and cylinder, causing extensive dama

4/23/97

3 - 43

REPAIR

ENGINE

PISTON ASSEMBLY— DISASSEMBLE

1. Remove compression rings (C) from piston (B) using ring expander.

2. Remove rails (A).

3. Remove spacer (D).

4. Remove retaining rings (E) by prying at indent (H).

5. Use wooden dowel to remove pin (F) from piston and connecting rod (G).

6. Inspect parts.

M55894

M55878

PISTON RING END GAP MEASUREMENT

IMPORTANT: If new rings are to be installed,

deglaze cylinder so rings will seat properly. (See Deglaze Cylinder Bore, later in this section.)

1. Use a clean or new piston to push piston compression ring squarely into bore, to a point where it normally runs.

M52110

2. Measure end gap (A).

3. Remove ring and file ends squarely until gap meets specification. Rings with too large a gap must be replaced. If one piston ring needs replaced, all must be replaced as a set.

Piston Ring End Gap (New Bore)

(12.5, 13, 14 hp) . . . . 0.3—0.5 mm (0.012—0.020 in.)

(15 hp) . . . . . . . . . . . . 0.27—0.51 mm (0.010—0.020)

Piston Ring End Gap (Used Bore) (Max)

(12.5, 13, 14 hp, 15hp) . . . . . . . . 0.77 mm (0.030 in.)

PISTON RING SIDE CLEARANCE

PISTON INSPECTION

1. Carefully remove piston rings.

M29946

IMPORTANT: Do not use caustic cleaners or wire

brush to clean aluminum piston. Piston damage can result.

2. Clean piston. Inspect for scoring or fractures.

3. Clean carbon from grooves using ring groove tool (A).

3 - 44

M52111

1. Measure piston ring side clearance (A) as shown at several points around piston.

2. Replace piston if measurements exceed clearance specifications.

Piston Ring-To-Groove Side Clearance Top Compression Ring (12.5, 13, 14 hp)

. . . . . . . . . . . . . .0.040—0.105 mm (0.002—0.004 in.)

(15 hp) . . . . . . . . 0.060—0.105 mm (0.002—0.004 in.)

4/23/97

ENGINE

Middle Compression Ring (12.5, 13, 14 hp)

. . . . . . . . . . . .0.040—0.072 mm (0.0016—0.0028 in.)

(15 hp) . . . . . . 0.040—0.085 mm (0.0015—0.0002 in.)

Oil Control Ring (12.5, 13, 14 hp)

. . . . . . . . . . . .0.551—0.675 mm (0.0217—0.0266 in.)

(15 hp) . . . . . . 0.176—0.026 mm (0.0069—0.0010 in.)

PISTON ASSEMBLY MEASUREMENT

REPAIR

5. Measure diameter of piston at point (D). Point (D) is 6 mm (0.25 in.) from skirt bottom and perpendicular to piston pin.

Piston Thrust Face OD

12.5, 13, 14 hp

. . . . . . . . . .86.941—86.959 mm (3.4229—3.4236 in.)

Wear Limit. . . . . . . . . . . . . . . . 86.814 mm (3.4179)

15 hp . . . . . 89.951—89.969 mm (3.5413—3.5420 in.)

Wear Limit. . . . . . . . . . . . . . . . 89.824 mm (3.5363)

M52148

M52112

NOTE: Connecting rod is available 0.25 mm (0.010

in.) undersize.

1. Tighten cap screws (A) to specification.

2. Measure inside diameter of connecting rod (B).

3. Measure outside diameter of crankshaft journal (C).

4. Determine connecting rod-to-crankshaft clearance.

Replace parts that are not within specifications.

Crankshaft Specifications: Connecting Rod Journal OD

New . . . . . . 38.958—38.970 mm (1.5338—1.5343 in.)

Wear Limit. . . . . . . . . . . . . . . . 38.94 mm (1.5328 in.)

Taper (maximum). . . . . . . . . . 0.012 mm (0.0005 in.)

Out-Of-Round (max) . . . . . . . 0.025 mm (0.0010 in.)

Crankshaft-to-Connecting Rod Clearance

New . . . . . . . . 0.030—0.055 mm (0.0012—0.0025 in.)

Wear Limit. . . . . . . . . . . . . . . . . . . (0.07 mm (0.0025)

Connecting Rod Specifications: Piston Pin End ID

New . . . .19.015—19.023 mm (0.7486—0.7489 in.)

Wear Limit. . . . . . . . . . . . . 19.036 mm (0.7495 in.)

Piston Pin OD.

New . . . . .18.995—19.00 mm (0.7478—0.7480 in.)

Wear Limit. . . . . . . . . . . . .(18.994 mm (0.7477 in.)

Connecting Rod Cap Screws Torque

8 mm Straight Shank . . . . . . 22.6 N•m (200 lb-in.)

Step Down Shank. . . . . . . . . 14.6 N•m (130 lb-in.)

6 mm Straight Shank . . . . . . 11.3 N•m (100 lb-in.)

M52125

6. Measure cylinder bore.

7. Replace piston and/or rebore cylinder block if not within specifications.

Piston Specifications: Thrust Face to Cylinder Bore Clearance (New)

12.5, 13, 14 hp

. . . . . . . . . . . .0.041—0.044 mm (0.0016—0.0017 in.)

15 hp . . . . . . .0.031—0.043 mm (0.0012—0.0016 in.)

Piston Pin Bore ID.

New . . . . . . 19.006—19.012 mm (0.7483—0.7485 in.)

Wear Limit. . . . . . . . . . . . . . . 19.025 mm (0.7490 in.)

4/23/97

3 - 45

REPAIR

g g

gTop

ENGINE

PISTON ASSEMBLY

IMPORTANT: Side of ring marked TOP faces top of

piston with Dykem stripe to left of end gap. Top compression ring has a blue Dykem stripe. Bottom compression ring has a pink Dykem stripe.

Ring Ga

“Pip” Mark

kem

Stripe

Piston

Compression Rin

NOTE: Install piston pin before retaining ring to

prevent possible scoring of bore.

M5879

IMPORTANT: Retaining rings (B) should be

installed with end gap (A) pointing up.

2. Install one piston pin retaining ring (B) in groove of piston bore (E).

3. Install pin (C) through piston bore (E) and connecting rod (D). Pin should install easily with thumb pressure.

4. Install remaining retaining ring (B) in opposite side.

Center Com Rin

Oil Rails

Oil Spacer

ression

1. Install rings as shown on piston using ring expander.

• Compression rin

• Note shape of compression rin

aps should be staggered 120°.

s and install as

shown.

• Compression rin mark up and D

• Install oil rin

s should be installed with “Pip”

kem strip to left of ring gap.

spacer first. Make sure that its ends

do not overlap.

• Sta

• Rin

er end gasp of oil rails 180° apart.

s should turn freely in grooves.

INSTALL PISTON ASSEMBLY

1. Install piston rings so piston ring end gaps are staggered 120° apart.

2. Compress rings with ring compressor tool.

3. Coat cylinder, piston skirt, rod, and cap bearing surfaces with oil.

M55898

M55871

4. Install piston with FLY mark (A) toward flywheel side of crankcase. Use wooden dowel to push piston into bore.

3 - 46

4/23/97

ENGINE

REPAIR

INSTALL CONNECTING ROD

M55875

5. Fasten connecting rod (D) and cap (C) to crankshaft.

6. Tighten cap screws (B) to specification.

7. Check connecting rod to crankshaft side clearance. Replace if not within specification.

8. Install balance shaft, camshaft, oil pan, and cylinder head. See appropriate procedures in this section.

Connecting Rod Specifications: Cap Screw Torque

8 mm Straight Shank . . . . . . . . 22.6 N•m (200 lb-in.)

Step Down Shank. . . . . . . . . . . 14.6 N•m (130 lb-in.)

6 mm Straight Shank . . . . . . . . 11.3 N•m (100 lb-in.)

Side Clearance . . . 0.18—0.41 mm (0.007—0.016 in.)

CRANKSHAFT REMOVAL & INSTALLATION

1. Remove camshaft and balancer assemblies.

CRANKSHAFT & MAIN BEARING INSPECTION

1. Inspect for cracks or chipped teeth.

2. Check crankshaft alignment, see next heading.

3. Measure journals (A), (B), and (C).

Replace crankshaft if bent, dama specifications.

Crankshaft Bearing Journal Specifications: Oil Pan End Main Journal OD:

New . . . . . . 41.915—41.935 mm (1.6502—1.6510 in.)

Wear Limit. . . . . . . . . . . . . . . 41.86 mm (1.648 in.)

Taper (maximum) . . . . . . . . 0.020 mm (0.0008 in.)

Out-of-Round (maximum) . 0.025 mm (0.0010 in.)

Flywheel End Main Journal OD:

New . . . .41.913—41.935 mm (1.7682—1.7691 in.)

Wear Limit. . . . . . . . . . . . . . . 44.84 mm (1.765 in.)

Taper (maximum) . . . . . . . . 0.022 mm (0.0009 in.)

Out-of-Round (maximum) . 0.025 mm (0.0010 in.) Connecting Rod Journal OD:

New . . . . . . 38.958—38.970 mm (1.5338—1.5343 in.)

Wear Limit. . . . . . . . . . . . . . 38.94 mm (1.5328 in.)

Taper (maximum) . . . . . . . . 0.012 mm (0.0005 in.)

Out-of-Round (maximum) . 0.025 mm (0.0010 in.)

ed, or not within

M52114

M58334

2. Remove and inspect crankshaft (A).

3. Install new seals (B) in crankcase and oil pan.

4. Install crankshaft carefully, DO NOT damage seals.

4/23/97

M52115

4. Measure inside diameter of crankshaft main bearing bore (D) in oil pan.

3 - 47

REPAIR

)

ENGINE

REMOVE AND INSTALL OIL PAN

M55945

M52116

5. Measure inside diameter of crankshaft main bearing bore (E) in crankcase.

6. Subtract journal OD. from bore ID. to determine if clearance is within specifications. Replace parts if not within specifications.

Crankshaft Sleeve Bearing Bore Specifications: Oil Pan & Crankcase Main Bearing Bore ID

47.98—48.03 mm (1.889—1.891 in.)

Main Bearing Bore-to-Crankshaft Clearance. . . . . .

. . . . . . . . . . . . . .0.03—0.09 mm (0.001—0.004 in.)

CRANKSHAFT ALIGNMENT

M80432

NOTE: Do not pry on gasket surface when removing

oil pan from crankcase.

1. Remove cap screws (A).

2. Pry oil pan from crankcase using flat blade screwdriver on splitting tabs (B).

3. Clean mating surfaces of crankcase and oil pan.

4. Replace crankshaft seals, see Remove And Install Oil Pan Seal and Remove And Install Crankcase Seal.

In alignment jig:

• Rotate crankshaft slowl

. Dial indicators (A

measure maximum Total Indicated Runout (TIR).

ine:

In en

• Rotate crankshaft slowl end of crankshaft usin

. Measure TIR at oil pan

dial indicator.

Replace crankshaft if not within specification.

Specifications: Crankshaft Maximum TIR

In Alignment Jig. . . . . . . . . . . 0.10 mm (0.004 in.)

In Engine. . . . . . . . . . . . . . . . . 0.15 mm (0.006 in.)

3 - 48

M55901

IMPORTANT: DO NOT get sealant in oil passage

(C). Apply just enough to seal both sides of oil passage when case halves are fastened together.

5. Apply 1.6 mm (1/16 in.) bead of RTV silicone sealant to oil pan flange. DO NOT block oil passage (C).

6. Apply grease to inside lip of crankshaft main bearing seal.

7. Install oil pan over crankshaft carefully to avoid damaging main bearing seal.

IMPORTANT: Be sure to align flats of balancer

shaft and oil pump inner rotor when installing oil pan.

Continued on next page

4/23/97

ENGINE

REPAIR

8. Install oil pan onto crankcase.

9. In sequence shown, tighten oil pan cap screws to specification

Specification:

Oil Pan Cap Screws . . . . . . . . . . 24 N•m (216 lb-in.) .

M52076

REMOVE AND INSTALL OIL PAN SEAL

M55946

3. Using a suitable driver and disc (B), install new oil seal to specification.

Specification: Oil Pan Seal Depth

. . . . . . . . . . . . . . . .2.49—2.98 mm (0.098—0.117 in.)

or until its top surface is flush with machined bore

opening.

4. Apply grease to inside lip of seal to aid installation.

IMPORTANT: Be sure to align flats (C) of balancer

shaft and oil pump inner rotor when installing oil pan.

M55903

IMPORTANT: DO NOT damage pan bore when

removing seal.

1. Remove and discard seal (A).

2. When replacing crankshaft seals, apply a thin film of LOCTITE®

598 or equivalent to the OD. of seal

5. Prepare and install oil pan, see Remove And Install Oil Pan.

REMOVE AND INSTALL CRANKCASE OIL SEAL

M55902

IMPORTANT: DO NOT damage crankcase bore

when removing seal.

1. Remove and discard crankcase oil seal (A).

2. When replacing crankshaft seals, apply a thin film of LOCTITE® 598 or equivalent to the OD. of seal.

3. Using a suitable driver and disc, install new oil seal to specification.

1. Loctite is a product of the Loctite Corporation.

4/23/97

3 - 49

REPAIR

ENGINE

Specification: Crankcase Seal Depth

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 mm (0.157 in.)

or until its top surface is flush with machined bore

opening.

IMPORTANT: Coat inside seal lip with grease to

aid installation. Install crankshaft carefully to avoid damaging seal.

4. Carefully install crankshaft seal.

INSPECT OIL PICKUP

1. Remove cap screw (A) and plate (B) to remove pickup screen (C).

2. Clean screen with approved solvent. Replace if damaged.

3. Install screen, plate, and cap screw.

4. Install oil pan, see Remove and Install Oil Pan.

M55872

OIL PUMP INSTALLATION

1. Remove cover (E), O-ring (D), pump outer rotor (C), and pump inner rotor (B).

2. Inspect rotor, pump, and inside surface of cavity (A) for scoring, discoloration, and wear.

M55874

OIL PUMP RELIEF VALVE INSPECT ION

1. Loosen cap screw(C) and retainer (B) to gain access to individual components.

2. Remove and measure spring (A), replace if not to specification.

Specification: Relief Valve Spring Free Length

. . . . . . . . . . . . . . . . . . . . . . . . 25.1968 mm (0.992 in.)

3. Inspect spring, piston (E), and body (D). Replace parts that are damaged or worn.

4. Install components with retainer and cap screw.

5. Install oil pan, see Remove And Install Oil Pan.

M52123

M85809

IMPORTANT: If oil leaks out between engine oil

base and tractor frame and not from the crankshaft seal, check O-ring groove (F) for casting flaws. If flashing is found in O-ring groove, cover the oil pump rotors to prevent contamination (G), use the sharpened end of a screwdriver as a chisel or a small file to remove flashing. Be careful not to gouge the bottom of the O-ring groove. Remove all chips or filings from the groove. (Recommend using a Q-Tip®).

3. Replace parts as necessary.

4. Lubricate parts (A, B, and C) with engine oil. Install in cavity.

5. Install O-ring and cover. Tighten cap screws to specification.

Oil Pump Cover Cap Screw Specification: New Oil Pan (Thread Forming) . . 6.2 N•m (55 lb-in.)

Used Oil Pan (Threads Cut). . . . . 4.0 N•m (35 lb-in.)

Oil Pump Cover-to-Rotor

Clearance . . . . . . . . . . . . . . . 0.076 mm (0.003 in.)

3 - 50

4/23/97

ENGINE

REPAIR

CYLINDER BLOCK REMOVE & INSTALL

M52133

All components must be removed from block before inspection or machine work can be performed.

CYLINDER BLOCK INSPECT

1. Clean and check block for cracks.

2. Cracks not visible to the eye may be detected by coating the suspected area with mixture of 25 percent kerosene and 75 percent light engine oil.

3. Wipe area dry and immediately apply coating of zinc oxide dissolved in wood alcohol. If crack is present, coating becomes discolored at the defective area.

4. Replace block if any cracks are found.

15 hp

New . . . .90.000—90.025 mm (3.5433—3.5443 in.)

Wear Limit. . . . . . . . . . . . . . 90.63 mm (3.5681 in.)

Out-of-Round (maximum) . . 0.12 mm (0.0047 in.)

Taper (maximum) . . . . . . . . . 0.05 mm (0.0020 in.)

Piston-to-Cylinder Clearance

12.5, 13, 14 hp. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . 0.041—0.044 mm(0.0016—0.0017 in.)

15 hp . . . . . 0.031—0.043 mm(0.0012—0.0016 in.)

CYLINDER BORE DEGLAZING

IMPORTANT: Remove crankshaft and internal

engine components when deglazing cylinder. Abrasives can cause engine damage.

1. Use the appropriate size flex-hone to deglaze cylinder bore.

M52125

5. Measure cylinder bore inside diameter at six places; two measurements 90° apart at top, middle, and bottom of ring travel.

6. Measure piston outside diameter perpendicular to piston pin bore.

NOTE: Pistons and rings are available 0.25 and 0.50

mm (0.010 and 0.020 in.) oversize.

Replace block or bore cylinder to accept larger piston if clearance exceeds specification.

Cylinder Bore Specifications:

12.5, 13, 14 hp

New . . . .87.000—87.025 mm (3.4252—3.4262 in.)

Wear Limit. . . . . . . . . . . . . 87.063 mm (3.4277 in.)

4/23/97

M58336

2. Deglaze cylinder bore using flex-hone to obtain

23—33°

3. Clean abrasive residue from cylinder using warm soapy water until clean white rags show no discoloration.

4. Dry cylinder and apply engine oil.

Specification:

Deglaze Crosshatch Pattern . . . . . . . . . . . . . 23—33°

crosshatch pattern.

3 - 51

REPAIR

ENGINE

REBORE CYLINDER BLOCK

IMPORTANT: Check stone for wear or damage.

Use correct stone.

M85811

NOTE: The cylinder block can only be rebored to use

0.25 and 0.50 mm (0.010 and 0.020 in.) oversize pistons and rings.

IMPORTANT: Do not use solvents to clean cylinder

bore. Solvents will not remove metal particles produced during honing.

11. Clean cylinder thoroughly using warm soapy water until clean white cloths show no discoloration.

12. Dry cylinder completely and apply thin coat of engine oil to appropriate mating surfaces.

Specifications: Oversize Limits

Initial . . . . . . . . . . . . . . . . . . . . . . 0.25 mm (0.010 in.)

Final. . . . . . . . . . . . . . . . . . . . . . . 0.50 mm (0.020 in.)

Drill Speed . . . . . . . . . . . . . . . . . . . . . . . . . . .250 rpm

Hone Cycles . . . . . . . . . . . . . . . . . . . . .60 per minute

Bore Crosshatch Pattern. . . . . . . . . . . . . . . .23—33°

Initial Bore Size—Coarse Stone

. . . . . . . . . . . . . . . . Until within 0.06 mm (0.0025 in.)

of desired bore size Secondary Bore Size—Burnish Stone

. . . . . . . . . . . . . . . . Until within 0.13 mm (0.0005 in.)

of desired bore size Final Bore Size—Finish Stone

. . . . . . . . . . . . Using 220—280 grit finishing stones

bore to desired size

1. Align center of bore to drill press center.

2. Adjust hone so lower end is even with lower end of cylinder bore.

3. Adjust coarse hone stones until they contact narrowest point of cylinder.

4. Coat cylinder with honing oil. Hone should turn by hand. Adjust if too tight.

5. Run drill press at about and down about

6. Stop press and check cylinder diameter several times during honing.

250 rpm

60 times per minute

. Move hone up

NOTE: Finish should not be smooth. It should have a

23—33° crosshatch pattern.

7. Remove hone when cylinder is within

(0.0025 in.)

8. Hone with burnishing stones until within

(0.0005 in.)

9. Hone with finish stones (220—280 grit) to final size.

10. Allow cylinder to cool completely; then, measure for new piston-to-cylinder bore running clearance, taper, and out-of-round.

of desired size.

0.06 mm

0.013 mm

3 - 52

4/23/97

ELECTRICAL

CONTENTS

Page

ELECTRICAL

SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

GENERAL SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

OTHER MATERIAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

THEORY AND DIAGNOSTIC INFORMATION. . . . . . . . . . . . . . . . . . . . . 4

THEORY OF OPERATION INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

DIAGNOSTIC INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

WIRE COLOR ABBREVIATION CHART. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

READING ELECTRICAL SCHEMATICS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

COMMON CIRCUIT TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

COMPONENT LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

WIRING HARNESS DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

STX30 (SN 010001—135159) (SN 595001—750000)

STX38 (SN 010001—139615) (SN 595001—750000) . . . . . . . . . . . . . . . . . . . . . 10

STX30 (SN 135160—160000) STX38 (SN 139616—160000) . . . . . . . . . . . . . . . . . 12

STX38 (SN 160001—210000). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

STX38 (SN 210001— ) STX46 (SN 240001— ) . . . . . . . . . . . . . . . . . . . . . . . . . 16

WIRING SCHEMATICS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

STX30 (SN 010001—135159) (SN 595001—750000)

STX38 (SN 010001—139615) (SN 595001—750000) . . . . . . . . . . . . . . . . . . . . . 18

STX30 (SN 135160—160000) STX38 (SN 139616—160000) . . . . . . . . . . . . . . . . . 20

STX38 (SN 160001—210000). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

STX38 (SN 210001— ) STX46 (SN 240001— ) . . . . . . . . . . . . . . . . . . . . . . . . . 24

CIRCUIT OPERATION AND DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . 26

CRANKING CIRCUIT OPERATION STX30 & STX38 (SN —210000). . . . . . . . . . 26

CRANKING CIRCUIT DIAGNOSIS STX30 & STX38 (SN —210000) . . . . . . . . . . 28

CRANKING CIRCUIT TEST POINTS STX30 & STX38 (SN —210000) . . . . . . . . 29

CRANKING CIRCUIT OPERATION STX38 (SN 210001— ) & STX46. . . . . . . . . . 30

CRANKING CIRCUIT DIAGNOSIS STX38 (SN 210001— ) & STX46 . . . . . . . . . . 32

IGNITION CIRCUIT OPERATION STX30 & STX38 (SN —210000) . . . . . . . . . . . 34

IGNITION CIRCUIT DIAGNOSIS STX30 & STX38 (SN —210000). . . . . . . . . . . . 36

IGNITION CIRCUIT TEST POINTS STX30 & STX38 (SN —210000). . . . . . . . . . 37

IGNITION CIRCUIT DIAGNOSIS STX30 & STX38 (SN —210000). . . . . . . . . . . . 38

IGNITION CIRCUIT TEST POINTS STX30 & STX38 (SN —210000). . . . . . . . . . 39

IGNITION CIRCUIT OPERATION STX38 (SN 210001— ) & STX46 . . . . . . . . . . . 40

IGNITION CIRCUIT DIAGNOSIS STX38 (SN 210001— ) & STX46. . . . . . . . . . . . 42

IGNITION CIRCUIT TEST POINTS STX38 (SN 210001— ) & STX46. . . . . . . . . . 43

CHARGING CIRCUIT OPERATION STX30 & STX38 (SN —210000) . . . . . . . . . 44

CHARGING CIRCUIT DIAGNOSIS STX30 & STX38 (SN —210000) . . . . . . . . . . 46

CHARGING CIRCUIT TEST POINTS STX30 & STX38 (SN —210000) . . . . . . . . 47

CHARGING CIRCUIT OPERATION STX38 (SN 210001— ) & STX46 . . . . . . . . . 48

CHARGING CIRCUIT DIAGNOSIS STX38 (SN 210001— ) & STX46 . . . . . . . . . . 50

CHARGING CIRCUIT TEST POINTS STX38 (SN 210001— ) & STX46 . . . . . . . . 51

3/12/97

4 - 1

CONTENTS

PTO CIRCUIT OPERATION STX30 & STX38 (SN —210000) . . . . . . . . . . . . . . . 52

PTO CIRCUIT DIAGNOSIS POINTS STX30 & STX38 (SN —210000). . . . . . . . . 54

PTO CIRCUIT TEST POINTS STX30 & STX38 (SN —210000) . . . . . . . . . . . . . . 55

PTO AND HEADLIGHTS CIRCUITS OPERATION

STX38 (SN 210001— ) & STX46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

PTO CIRCUIT DIAGNOSIS STX38 (SN 210001— ) & STX46. . . . . . . . . . . . . . . . 58

PTO CIRCUIT TEST POINTS STX38 (SN 210001— ) & STX46 . . . . . . . . . . . . . . 59

HEADLIGHTS CIRCUIT DIAGNOSIS STX38 (SN 210001— ) & STX46 . . . . . . . . 60

HEADLIGHTS CIRCUIT TEST POINTS STX38 (SN 210001— ) & STX46 . . . . . . 61

TESTS AND ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

GROUND CIRCUIT TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

BATTERY TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

CHARGE BATTERY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

BATTERY LOAD TEST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

REGULATED VOLTAGE OUTPUT TEST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

UNREGULATED VOLTAGE OUTPUT TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

STARTER SOLENOID TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

STARTER AMP DRAW TEST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

IGNITION SPARK TEST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

IGNITION MODULE AIR GAP ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

IGNITION MODULE TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

SEAT SWITCH TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

BRAKE PEDAL/PARK BRAKE SWITCH TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

HEADLIGHT SWITCH TEST (OPTIONAL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

KEY SWITCH TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

PTO SWITCH TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

PTO CLUTCH TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

PTO CLUTCH AIR GAP STX30 & STX38 (SN —210000). . . . . . . . . . . . . . . . . . . 72

FLYWHEEL MAGNETS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

TRANSMISSION NEUTRAL SWITCH STX30 & STX38 ( —210000) . . . . . . . . . . 73

REPAIR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

REMOVE AND INSTALL KEY SWITCH AND PTO SWITCH. . . . . . . . . . . . . . . . . . 74

REMOVE AND INSTALL SEAT SWITCH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

REMOVE AND INSTALL STARTER SOLENOID . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

REMOVE AND INSTALL STATOR AND IGNITION MODULE. . . . . . . . . . . . . . . . . 75

REPAIR PTO CLUTCH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

REMOVE AND INSTALL STARTER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

REPLACE BENDIX DRIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

REPAIR STARTER AND REPLACE BRUSHES. . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

REPAIR STARTER ARMATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

REMOVE AND INSTALL TRANSMISSION NEUTRAL SWITCH

STX30 & STX38 (SN —210000). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

ELECTRICAL

4 - 2

3/12/97

ELECTRICAL

SPECIFICATIONS GENERAL SPECIFICATIONS

Battery:

Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

BCI group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .U-1

CCA rating (Amps at -18

Reserve capacity (minutes at 25 Amps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Specific gravity (minimum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.225 points

Electrolyte required fill (Approximate). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 L (2.0 qt)

Load test (minimum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 amp for 15 seconds

Ignition:

Primary coil resistance

Secondary (Plug wire and core) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9 - 10.85 K ohms

Air gap. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.2 - 0.3 mm (0.008 - 0.012 in.)

SPECIFICATIONS

C (0oF),. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

One direction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 1000 ohms

Other direction (Minimum). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 K ohms

Spark Plug:

Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.00 mm (0.040 in.)

Torque. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38-43 N•m (28-32 lb-ft.)

Starter:

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bendix

Amp draw

Loaded (engaging engine) . . . . . . . . . . . . . . . . . . . . . . .180 amps at 225 engine rpm

Stator:

Stator size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 amp

Regulated voltage at high idle (minimum). . . . . . . . . . . . . . . . . . . . . . . .12.2 - 14.7 volts

Unregulated voltage at high idle:

Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 VAC

Domestic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 VAC

PTO Clutch:

Coil Resistance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10 Ohms

Current Draw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.5 Amps

3/21/97

OTHER MATERIAL

Number Name Use

PT569 John Deere NEVER-SEEZ®

Lubricant

Lubricate crankshaft.

4 - 3

THEORY AND DIAGNOSTIC INFORMATION

ELECTRICAL

THEORY AND DIAGNOSTIC INFORMATION

THEORY OF OPERATION INFORMATION

The theory of operation stories divide the electrical system into individual circuits by function. Each circuit is isolated from the main wiring schematic and only shows the components that are used in it. The story contains information on function, operating conditions, and theory of operation. The circuit schematics are drawn with the components in the operating position, with the power, or battery positive, into them across the top and the ground, or battery negative, across the bottom.

DIAGNOSTIC INFORMATION

The diagnostic procedures is used to test the complete circuit regardless of the problem or complaint. Select a symptom or system from the quick check or troubleshooting chart and follow the test procedures under that heading.

The diagnostic procedure lists:

• Test conditions

• Test sequence

• Test location

• Normal reading

• Check or test to perform if reading is not normal

When performing the test or check, be sure to set your machine up to the test conditions listed and follow the sequence carefully. The middle gives the reading or condition that should be obtained when performing the test or check. If the results of the test or check are not normal, perform the test, check, or adjustment listed in the third column to repair the malfunction. The detailed tests or adjustments referred to in the column are located at the end of that group. The system diagram that accompanies each test procedure is drawn to resemble machine components. The key number on the art matches the number in the

LOCATION”

exact point the test is to be made.

column and the leader line points to the

“NORMAL”

“IF NOT NORMAL”

column

“TEST

WIRE COLOR ABBREVIATION CHART

Blk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Black

Blu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Blue

Brn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brown

Grn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Green

Gry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gray

Org. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orange

Pnk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pink

Pur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Purple

Red. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Red

Tan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tan

Wht. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .White

Yel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yellow

Blk/Wht. . . . . . . . . . . . . . . . . . . . . . . . . .Black/White

Blu/Wht. . . . . . . . . . . . . . . . . . . . . . . . . . Blue/White

Brn/Wht . . . . . . . . . . . . . . . . . . . . . . . . Brown/White

Brn/Yel . . . . . . . . . . . . . . . . . . . . . . . . Brown/Yellow

Dk Blu. . . . . . . . . . . . . . . . . . . . . . . . . . . . Dark Blue

Dk Brn/Lt Grn. . . . . . . . . . Dark Brown/Light Green

Dk Brn/Red. . . . . . . . . . . . . . . . . . Dark Brown/Red

Dk Brn/Yel . . . . . . . . . . . . . . . . . Dark Brown/Yellow

Dk Grn . . . . . . . . . . . . . . . . . . . . . . . . . Dark Green

Lt Blue . . . . . . . . . . . . . . . . . . . . . . . . . . . Light Blue

Lt Grn. . . . . . . . . . . . . . . . . . . . . . . . . . Light Green

Lt Org. . . . . . . . . . . . . . . . . . . . . . . . . .Light Orange

Org/Wht . . . . . . . . . . . . . . . . . . . . . . . Orange/White

Pnk/Blk. . . . . . . . . . . . . . . . . . . . . . . . . . Pink/Black

Pur/Wht . . . . . . . . . . . . . . . . . . . . . . . .Purple/White

Red/Blk. . . . . . . . . . . . . . . . . . . . . . . . . . . Red/Black

Red/Wht. . . . . . . . . . . . . . . . . . . . . . . . . .Red/White

Wht/Blk. . . . . . . . . . . . . . . . . . . . . . . . . .White/Black

Wht/Red. . . . . . . . . . . . . . . . . . . . . . . . . .White/Red

4 - 4

Yel/Blk . . . . . . . . . . . . . . . . . . . . . . . . . Yellow/Black

Yel/Red . . . . . . . . . . . . . . . . . . . . . . . . . Yellow/Red

Yel/Wht. . . . . . . . . . . . . . . . . . . . . . . . .Yellow/White

3/21/97

ELECTRICAL

THEORY AND DIAGNOSTIC INFORMATION

READING ELECTRICAL SCHEMATICS

The schematic is made up of individual circuits laid out in a sequence of related functions. It is formatted with all power wires (A) across the top and all ground wires (B) across the bottom. Current flow is generally from top to bottom through each circuit and component. All components are shown in the OFF position. The diagram does not list connector (C) information unless needed to avoid confusion. If the connector is shown, the number next to it is the terminal pin location (D) in the connector.

Each component is shown by a symbol (E), its name (F), and an identification code (G). The identification code contains a device identifying letter (H) and number (I).

S1 Key Switch

Wht

Red

Start Run Off

K1 Start Relay

210 Red

F1 Fusible Link

Wht Red

The identifying letter is always the same for a specific component, but the identifying numbers are numbered consecutively from upper left to lower right. The terminal designation (J) is placed directly outside the symbol next to the connecting wire path. Switch positions (K) are also placed directly outside the symbol. The solid line (L) shows the position the switch is currently in and dash lines (M) represent other switch positions.

Each circuit is identified at the bottom of the drawing by a section number (N) and section name (O).

The circuit number (P) and wire color (Q) of the wires are shown directly next to the wire path.

The same component name and identification code are used consistently on all diagrams in this section. Components can be easily cross-referenced.

Off

15 Amp

Fuse

414 Yel/

Blk

15 Amp

Fuse

800

Pink

Seat

K2 Ignition

Relay

S2 Seat Switch

710 Pur

G1 Battery

Blk

W1 Shielded Ground

3/21/97

215

Red

Org

721 Pur/ Wht

M1 Starting

Motor

SE1-Power and Cranking Circuit

W2 Engine Wiring Harness

Ignition

Coil

Yel/Wht

Spark Plug

Wht

SE2-Ignition and Interlock Circuit

805 Pnk/Blk

Yel/

Wht

Yel/Wht

Yel/ Wht

T2 Ignition Coil

E2 Spark

Blk/Yel

Plug

SE3-PTO and Interlock

105 Blk

4 - 5

THEORY AND DIAGNOSTIC INFORMATION

M85602 mif

ELECTRICAL

COMMON CIRCUIT TESTS

Shorted Circuit:

A shorted circuit may result in the wrong component operating (i.e. improper wire-to-wire contact). To test for a shorted or improperly wired circuit:

1. Turn component switch ON.

2. Start at the controlling switch of the component that should not be operating.

3. Follow the circuit and disconnect wires at connectors until component stops operating.

4. Shorted or improper connections will be the last two wires disconnected.

Grounded Circuit:

Grounded circuits usually result in no component operation or a blown fuse.

M85600 mif

High Resistance or Open Circuit:

High resistance or open circuits usually result in slow, dim or no component operation (i.e. poor, corroded, or disconnected connections). Voltage at the component will be low when the component is in operation. To test for high resistance and open circuits:

1. Check all terminals and grounds of the circuit for corrosion.

2. If terminals are not corroded or loose, the problem is in the component or wiring.

M85601 mif

4 - 6

3/21/97

ELECTRICAL

NOTES

THEORY AND DIAGNOSTIC INFORMATION

3/21/97

4 - 7

ELECTRICAL

COMPONENT LOCATION

E2 Headlights (Optional)

A1 Ignition Module

COMPONENT LOCATION

Stator

Y2 Fuel Shut-Off Solenoid (Optional)

Regulator/Rectifier

PTO Clutch

Spark

Plug

Brake Switch

Starter Motor

Seat Switch

Starter Solenoid

F1 Fuse or

Circuit Breaker STX30 & STX38 (SN —210000)

Neutral Start Switch STX30 & STX38 (SN —210000)

PTO Switch

Light Switch (Optional)

Key Switch

K2 Start Relay STX30 & STX38 (SN —210000)

Battery

M55829

4 - 8

3/21/97

ELECTRICAL

TROUBLESHOOTING

Problem or Symptom

Check or Solution

Engine will not crank.

Engine cranks but will

not start.

Engine starts hard or

will not stay running.

Engine misses or runs

Weak or no spark.

Engine will not shut off.

PTO clutch will not

engage or will not

Battery goes dead,

TROUBLESHOOTING

discharges or

Optional headlights will

not turn on or will not

Optional fuel shut-off

solenoid will not open.

Optional fuel shut-off

solenoid will not close.

Engine dies when shift

lever is engaged.

Engine dies when PTO

switch is engaged.

See power circuit test points. See cranking circuit test

points. Check ground circuit test

points. Test battery and connections. See ignition circuit test

points. See charging circuit test

points. See starter tests. See PTO circuit test points. See optional headlight circuit

test points. See optional fuel shut-off

solenoid circuit test points. Check for shorted circuit.

● ● ●●●●●●●

●

●● ●● ● ●● ●●

● ●●●● ●

●● ●●●● ● ●●●●●

●● ● ●● ●

●

● ● ● ●

●

● ● ● ●

●● ● ●● ● ● ●●●●●

Check for high resistance or open circuit.

Check for correct spark plug and spark plug air gap.

Check for correct ignition module to flywheel magnet air gap.

Check strength of flywheel ignition module magnet and/ or flywheel stator magnets.

See fuel and air system tests and adjustments.

Check for stator shorted to ground.

Check seat switch is plugged in and spring inside connector is good.

3/21/97

●● ● ●● ●●●●●●●

● ●●●

● ●●● ●●

● ●●

● ●

4 - 9

WIRING HARNESS DIAGRAMS

WIRING HARNESS DIAGRAMS STX30 (SN 010001—135159) (SN 595001—750000)

STX38 (SN 010001—139615) (SN 595001—750000)

S2 PTO Switch

S1 Key Switch

500 510

750

510 520

720

520

S5 Headlight Switch (Optional)

941

K2 Start Relay

ELECTRICAL

110

105 110

710 714

100 105

700

S1 Key Switch

941 940

200

714

F2 Fuse

450

1 2

715

S4 Seat Switch

650 800

716

650

500

Diode

715

800 500

716 800

110

100

200

F2 Fuse or Circuit Breaker

Battery Ground

Circuit Number

100 0.5 Blk S1, Battery

105 0.5 Blk K2, S1 110 0.5 Blk K2, K2 120 1.0 Blk Y1, W2 125 1.0 Blk E2, 120 Blk 200 1.0 Red S1, F1 210 1.0 Red K1, X1, N1 450 1.0 Yel/Wht E2, S5 500 0.8 Yel S1, S4 510 1.0 Yel S2, S1 520 1.0 Yel S2, S5

Wire Size

Color

4 - 10

Termination Points

Ground

Circuit Number

650 0.8 Brn S4, Y2 700 0.8 Pur S1, K1 710 0.8 Pur S1, S3 714 0.8 Pur/Blk S1, F2 715 0.5 Pur/Blk F2, Diode 716 0.5 Diode Diode, K2 720 0.8 Pur S3, S2 750 1.0 Blu S2, Y1 800 0.8 Pnk S4, K2 940 0.5 Wht S1, X1 941 0.5 Wht K2, S1

Wire Size

Color

Termination Points

3/21/97

ELECTRICAL

S3 Neutral Start

Switch

710

720

A1 Ignition Module

940

X1 Engine

Connector

210 N1 Regulator/rectifier

WIRING HARNESS DIAGRAMS

Y2 Fuel Shut-off Solenoid

650

700

K1 Starter Solenoid

210

120

K1 Starter Solenoid

W1 Engine Ground

450

125

750

120

E2 Headlights

Y1 PTO Clutch

3/21/97

4 - 11

WIRING HARNESS DIAGRAMS

7 7

STX30 (SN 135160—160000) STX38 (SN 139616—160000)

S2 PTO Switch

750

510 520

S1 Key Switch

720

520

ELECTRICAL

S5 Headlight Switch (Optional)

450

500

700

10 14

100

510

200

941

F2 Fuse Holder

Circuit Number

100 0.5 Blk S1, W1 105 0.5 Blk K2, W1 110 0.5 Blk K2, K2 120 1.0 Blk Y1, W2 125 1.0 Blk E2, W2 130 0.8 Blk K1, W1 200 1.0 Red S1, F1 201 0.5 Red-

210 1.0 Red K1, X1, N1 450 1.0 Yel/Wht S5, E2 500 0.8 Yel S1, S4

Wire Size

Color

Fuse

Termination Points

F1, G1

510

1 2

715

714

715

714

Circuit Number

510 1.0 Yel S2, S1 520 1.0 Yel S2, S5 650 0.8 Brn S4, Y2 700 0.8 Pur S1, K1 710 0.8 Pur S1, S3 714 0.8 Pur/Blk S1, F2 715 0.5 Pur/Blk F2, Diode, K2 716 0.5 Diode Diode, K2 720 0.8 Pur S2, S3 750 1.0 Blu S2, Y1 800 0.8 Pnk S4, K2 940 0.5 Wht K2, A1, X1 941 0.5 Wht K2, S1

Wire Size

Color

Termination Points

500

650 800

S4 Seat Switch

4 - 12

3/21/97

ELECTRICAL

K2 Start Relay

110

940

941

110

S3 Neutral Start Switch

710

940 A1 Ignition Module

720

WIRING HARNESS DIAGRAMS

X1 Engine

Connector

210 N1 Regulator/rectifier

Y2 Fuel Shut-off Solenoid

650

716

715

800

110

716 800

105 110

W1 Frame Ground

G1 Battery

201

200

F1 Fusible

Link

105

100

700

210

K1 Starter Solenoid

E2 Headlights

125

450

750

120

125

120

PTO Clutch

W2 Engine Ground

3/21/97

4 - 13

WIRING HARNESS DIAGRAMS

STX38 (SN 160001—210000)

750

510 520

S2 PTO Switch

720

520

S5 Headlight Switch (Optional)

450

ELECTRICAL

K2 Start Relay

110

940

941

110

716 800

105 110

710

714

100

700

S1 Key Switch

941

200

500 510

F2 Fuse Holder

714

520

510

1 2 3

715

500

715

716

S4 Seat Switch

714

650 800

Diode

110

715

800

Circuit Number

100 0.5 Blk S1, W1 105 0.5 Blk K2, W1 110 0.5 Blk K2, K2 120 1.0 Blk Y1, W2 125 1.0 Blk E2, W2 130 0.8 Blk K1, W1 200 1.0 Red S1, F1 201 0.5 Red-

210 1.0 Red K1, X1, N1 450 1.0 Yel/Wht S6, S5 500 0.8 Yel S1, S4

Wire Size

Color

Fuse

4 - 14

Termination Points

F1, K1

Circuit Number

Wire Size

Color

Termination Points

3/21/97

ELECTRICAL

S3 Neutral Start

Switch

710

940 A1 Ignition Module

720

WIRING HARNESS DIAGRAMS

X1 Engine

Connector

210 N1 Regulator/rectifier

Y2 Fuel Shut-off

Solenoid

650

K1 Starter Solenoid Ground

K1 Starter Solenoid

700

210

200

4 5

K1 Starter Solenoid

B+

201

F1 Fusible Link

130

100

105

Headlights

450

125

750

120

125

120

PTO Clutch

3/21/97

W1 Frame

Ground

W2 Engine

Ground

4 - 15

WIRING HARNESS DIAGRAMS

STX38 (SN 210001— ) STX46 (SN 240001— )

S2 PTO Switch

705

ELECTRICAL

700

S1 Key Switch

942 941

200

100

400 401

946

941

400 450

750

700

450

S5 Headlight Switch (Optional)

451

K1 Starter Solenoid

450

K1 Starter Solenoid Ground

200

1 2

201

F1 Fusible Link

105

710

220

K1 Starter Solenoid

B+

201

105

100

110

W1 Frame Ground

Circuit Number

100 1.0 Blk S1, W1 105 1.0 Blk K1, W1 110 0.5 Blk W1, S4 120 0.8 Blk E2, W2 125 0.8 Blk Y1, W2 200 0.8 Red S1, F1 201 0.5 Lt Org-

220 0.8 Red K1, X1, N1 400 0.8 Yel S1, S2 401 0.5 Yel Y2, S1

Wire Size

Color

Fuse

4 - 16

Termination Points

F1, K1

Circuit Number

450 0.8 Yel/Wht S5, S2 451 0.8 Yel/Wht E2, S5 700 0.8 Pur S1, S2 705 0.8 Pur/Wht S2, S3 710 0.8 Pur K1, S3 750 0.8 Blu S2, Y1 940 1.0 Wht S3, X1, A1 941 1.0 Wht S2, S1 942 0.5 Wht S3, S1 945 0.5 Wht/Blk S4, S3 946 0.5 Wht/Blk S4, S2

Wire Size

Color

Termination Points

S4 Seat Switch

110

945 946

3/21/97

John Deere stx38 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

INTRODUCTION

METRIC FASTENER TORQUE VALUES

SPECIFICATIONS

ESSENTIAL TOOLS

OTHER MATERIALS

SERVICE PARTS KITS

TROUBLESHOOTING

DIAGNOSIS

SPECIFICATIONS

COMPONENT LOCATION

TROUBLESHOOTING

WIRING HARNESS DIAGRAMS