Briggs & Stratton Vanguard 430000, Vanguard 580000 User Manual

POST OFFICE BOX 702 MILWAUKEE, WI 53201 USA

BRIGGS&STRATTON

CORPORATION

MS - 0750 - 5/10

www.ThePowerPortal.com (Dealers) BRIGGSandSTRATTON.COM (consumers)

272147 - Vanguard ™ Single Cylinder OHV Air-Cooled Engines 272144 - Vanguard

™

Twin Cylinder OHV Air-Cooled Engines

275429 - Vanguard

™

Twin Cylinder OHV Liquid-Cooled Engines

MS-1055 - Vanguard

™

3-Cylinder OHV Liquid-Cooled Diesel Engines

Other Briggs & Stratton Commercial Power Repair Manuals:

Briggs & Stratton

VANGUARD

™

3-CYLINDER OHV LIQUID-COOLED GASOLINE ENGINES

5/10

Vanguard

™ 3-Cylinder OHV

Liquid-Cooled Gasoline Engines

Quality Starts With A

Master Service Technician

FORWARD

This manual was written to assist engine technicians and service personnel with the repair and maintenance procedures for Briggs & Stratton® engines. It assumes that persons using this manual have been properly trained in and are familiar with the servicing procedures for these products, including the proper use of required tools and safety equipment and the application of appropriate safety practices. Persons untrained or unfamiliar with these procedures or products should not attempt to perform such work.

Proper maintenance and repair is important to safe, reliable operation of all engines and engine-driven systems. The troubleshooting, testing, maintenance, and repair procedures described in this manual are appropriate for the Briggs & Stratton® engines described herein. Alternative methods or procedures may pose risk to personal safety and the safety and/or reliability of the engine and are not endorsed or recommended by Briggs & Stratton.

All information, illustrations, and specifications contained in this manual were based on the data available at the time of publication. Briggs & Stratton Corporation reserves the right to change, alter, or otherwise improve the product or the product manuals at any time without prior notice.

Briggs & Stratton offers two complementary publications to enhance understanding of engine technology, maintenance, and repair. (Neither publication, however, is a substitution for a recognized training program for engine technicians.)

• For consumers, Small Engine Care & Repair (p/n 274041) provides a comprehensive overview of how small air-cooled engines work, basic troubleshooting, and step-by-step maintenance procedures.

• For engine technicians and consumers alike, an in-depth study of engine theory and operation can be found in the textbook Small Engines (p/n CE8020).

Both publications can be purchased at BRIGGSandSTRATTON.COM or through a local Authorized Briggs & Stratton Service Dealer.

No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying or recording by any information storage and retrieval system, without prior written permission from Briggs & Stratton Corporation.

This engine repair manual includes the following

engine models:

• MODEL 430000

• MODEL 580000

6

SECTION 1 - Safety

SECTION 2 - Cylinder Heads and Valves

SECTION 3 - Governor, Timing Gears, and Gear Case

SECTION 4 - Flywheel and Rear Seal Retainer

SECTION 5 - Cylinder Block Disassembly

SECTION 6 - Cylinder Block Inspection and Repair

SECTION 7 - Crankshaft, Camshaft, and Bearings

1

2

3

4

5

6

7

SECTION 8 - Pistons, Rings, and Connecting Rods

SECTION 9 - Cylinder Block Assembly

SECTION 10 - Fuel System and Related Components

SECTION 11 - Ignition, Electrical System

SECTION 12 - Lubrication System

SECTION 13 - Cooling System

SECTION 14 - Engine Specifications

8

9

10

11

12

13

14

THISPROPER SERVICE AND REPAIR IS IMPORTANT TO THE SAFE, ECONOMICAL AND RELIABLE

SECTION 1 - SAFETY AND MAINTENANCE

SAFETY INFORMATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4

1

3

1

SAFETY INFORMATION

This repair manual contains safety information that is designed to:

• Make you aware of hazards associated with engines.

• Inform you of the risk of injury associated with those hazards.

• Tell you how to avoid or reduce the risk of injury.

Signal Words in Safety Messages

The safety alert symbol is used to identify safety information about hazards that can result in personal injury.

A signal word ( is used with the alert symbol to indicate the likelihood and the potential severity of injury. In addition, a hazard symbol may be used to represent the type of hazard.

DANGER indicates a hazard which, if not

avoided, will result in death or serious injury.

DANGER, WARNING, or CAUTION)

WAR NING

Before attempting to service this equipment, read and understand this manual and the operating instructions of the engine and the equipment it powers.

Failure to follow instructions could result in property damage, serious injury (including paralysis) or even death.

Hazard Symbols and Meanings

FIRE EXPLOSION

ELECTRIC

SHOCK

WARNING indicates a hazard which, if

not avoided, could result in death or serious injury.

CAUTION indicates a hazard which, if

not avoided, could result in minor or moderate injury.

NOTICE indicates a situation that could

result in damage to the product.

Prior to work, read and understand the section(s) of this manual that pertain to the job. Follow all safety warnings.

• Always use fresh gasoline. Stale fuel can cause gum deposits in the carburetor and cause leakage, flow restrictions, or other problems.

• Check fuel lines and fittings frequently for cracks or leaks and replace if necessary.

EXPLOSIVE PRESSURE

ENTANGLEMENT KICKBACK AMPUTATION

TOXIC

FUMES

Battery posts, terminals, and related accessories contain lead and lead compounds - chemicals known to the State of California to cause cancer and reproductive harm. Wash hands after handling.

HOT

SURFACE

READ

MANUAL

WARNING

GOGGLES

CHEMICAL

BURNS

4

WARNING

WAR NING

Certain components in this product and its related accessories contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. Wash hands after handling.

WARNING

Briggs & Stratton does not approve or authorize the use of these engines on 3-wheel All Terrain Vehicles (ATVs), motor bikes, fun/recreational go-karts, aircraft products, or vehicles intended for use in competitive events. Use of these engines in such applications could result in property damage, serious injury (including paralysis), or even death.

WARNING

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

WAR NING

Running engines produce heat. Severe burns can occur on contact.

• Allow muffler, engine cylinder fins, and radiator to cool before touching.

• Remove accumulated combustibles from muffler area and cylinder area.

• It is a violation of California Public Resource Code, Section 4442, to use or operate the engine on any forest-covered, brush-covered, or grass-covered land unless the exhaust system is equipped with a spark arrester, as defined in Section 4442, maintained in effective working order. Other States and Federal jurisdictions may have similar laws. Contact the original equipment manufacturer, retailer, or dealer to obtain spark arrester designed for the exhaust system installed on this engine.

Fuel and its vapors are extremely flammable and explosive. Fire or explosion can cause severe burns or death.

When adding fuel:

• Turn engine OFF and let engine cool for at least 2 minutes before removing the fuel cap.

• Fill fuel tank outdoors or in a well-ventilated area.

• Do not overfill fuel tank. To allow for expansion of the gasoline, do not fill above the bottom of the fuel tank neck.

• Keep gasoline away from sparks, open flames, pilot lights, heat and other ignition sources.

• Check fuel lines, tank, cap, and fittings frequently for cracks or leaks. Replace if necessary.

• If fuel spills, wait until it evaporates before starting engine.

When starting engine:

• Make sure spark plug, muffler, fuel cap, and air cleaner are in place.

• Do not crank engine with spark plug removed.

• If fuel spills, wait until it evaporates before starting engine.

• If engine floods, set choke (if equipped) to OPEN/RUN position. Place throttle (if equipped) in FAST and crank until engine starts.

When operating equipment:

• Do not tip engine or equipment at an angle which would cause fuel to spill.

• Do not choke carburetor to stop engine.

• Never start or run the engine with the air cleaner assembly (if equipped) or the air filter (if equipped) removed.

When changing oil:

• If you drain the oil from the top oil fill tube, the fuel tank must be empty or fuel can leak out and result in a fire or explosion.

When transporting equipment:

• Transport with fuel tank empty or with fuel shut-off valve set to OFF.

When storing gasoline or equipment with fuel in the tank:

• Store away from furnaces, stoves, water heaters, or other appliances that have a pilot light or other ignition source because they can ignite gasoline vapors.

1

5

WAR NING

1

Unintentional sparking can result in fire or electrical shock. Unintentional start-up can result in entanglement, traumatic amputation, or severe lacerations.

Before performing adjustments or repairs:

• Disconnect spark plug wire and keep it away from spark plug.

• Disconnect the negative (-) battery terminal.

When testing for spark:

• Use approved spark plug tester.

• Do not check for spark with spark plug removed.

WAR NING

Engines give off carbon monoxide, an odorless, colorless, poison gas. Breathing carbon monoxide can cause nausea, fainting, or death.

• Start and run engine outdoors.

• Do not start or run engine in an enclosed area, even if doors and windows are open.

WAR NING

Starting engine creates sparking. Sparking can ignite nearby flammable gases. Explosion and fire could result.

• If there is a natural or LP gas leak in the area, do not start engine.

• Do not use pressurized starting fluids because vapors are flammable.

Charging batteries produce hydrogen gas. Do not store or charge a battery near an open flame or device that utilizes a pilot light or can create a spark.

WAR NING

Damaged, worn, or loose fuel components can leak fuel. Explosion or fire could result.

• All fuel components should be in good condition and properly maintained.

• Repairs should only be made with factory approved parts.

• Repair work should be done by a qualified technician.

• Flexible supply lines should be checked regularly to make sure they are in good condition.

WAR NING

Rapid retraction of starter cord (kickback) will pull hand and arm toward engine faster than you can let go. Broken bones, fractures, bruises, or sprains could result.

• When starting engine, pull the starter cord slowly until resistance is felt and then pull rapidly to avoid kickback.

• Remove all external equipment/engine loads before starting engine.

• Direct-coupled equipment components, such as but not limited to blades, impellers, pulleys, and sprockets, must be securely attached.

WAR NING

Rotating parts can contact or entangle hands, feet, hair, clothing, or accessories. Traumatic amputation or severe lacerations can result.

• Operate equipment with guards in place.

• Keep hands and feet away from rotating parts.

• Tie up long hair and remove jewelry.

• Do not wear loose-fitting clothing, dangling drawstrings, or items that could become entangled in the equipment.

6

WAR NING

Prolonged or repeated contact with used motor oil could cause injury.

• Used motor oil has been shown to cause skin cancer in certain laboratory animals.

• Thoroughly wash exposed areas with soap and water.

SECTION 2 - CYLINDER HEAD AND VALVES

REMOVE CYLINDER HEAD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

DISASSEMBLE CYLINDER HEAD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -10

REMOVE VALVES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -11

INSPECT CYLINDER HEAD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -12

DISASSEMBLE ROCKER ARM SHAFT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -15

ASSEMBLE ROCKER ARM SHAFT- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -16

ASSEMBLE CYLINDER HEAD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -17

INSTALL CYLINDER HEAD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -18

ADJUST VALVES- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -20

2

7

2

8

Remove Cylinder Head

1. Drain cooling system and disconnect radiator hoses and bypass hose at water pump.

2. Remove the alternator adjusting bracket screw (A, Figure 1), V-belt (B), and fan (C), from the engine.

Figure 1

3. Remove the water pump pulley (A, Figure 2), water pump (B), and exhaust manifold (C) from the engine.

2

Figure 3

6. Remove the ignition coil bracket (Figure 4) and the ignition coils.

NOTE: Remove the exhaust system before removing exhaust manifold.

Figure 2

4. Remove the fuel line (A, Figure 3) and governor link and spring (B).

5. Remove the intake manifold (C) and spark plug wires and spark plugs (D).

Figure 4

7. Remove the valve cover (Figure 5).

Figure 5

8. Set the Number 1 piston at Top Dead Center (TDC).

9

9. Rotate crankshaft pulley until timing mark on pulley is aligned with reference point (A, Figure 6) on timing cover (B).

Disassemble Cylinder Head

1. Loosen cylinder head bolts in the order shown (Figure 8).

2

Figure 6

• If intake and exhaust valves have clearance, the Number 1 piston is at TDC (compression stroke).

• If intake and exhaust valves do not have clearance, turn crankshaft pulley one complete revolution. Valves will then have clearance.

10. Remove rocker arm assembly (A, Figure 7) and push rods.

11. Remove valve stem caps (B).

NOTE: Mark push rods so that they may be reassembled in their original position.

2

Figure 8

Figure 7

10

Remove Valves

2. Refer to the following cylinder head components (Figure 9) when proceeding to the next part of the disassembly process:

• (A) - Cylinder Head Assembly

• (B) - Cylinder Head Gasket

• (C) - Valve Stem Cap

• (D) - Valve Spring Retainer Locks

• (E) - Valve Spring Retainer

• (F) - Valve Spring

• (G) - Valve

• (H) - Valve Spring Seat

• (J) - Valve Stem Seal

• (K) - Valve Guide

2

Figure 10

NOTE: Place a shop rag or short section of fuel line under valves inside combustion chamber to hold valve in place while compressing spring.

4. Use Valve Spring Compressor #19417 to compress valve springs. Remove the following parts:

• Valve Spring Retainer Locks

• Valve Spring Retainer

• Valve Spring

• IN and EX valve

• Valve spring seats

5. Remove and discard valve stem seals (Figure 11).

Figure 9

3. Remove valves (Figure 10).

11

Figure 11

2

Inspect and Repair

Inspect Cylinder Head

NOTE: Be sure all gasket material is removed from

surfaces before checking. Use a gasket scraper if necessary.

1. Inspect cylinder head for cracks or damage.

2. Use a straight edge (A, Figure 12) to check cylinder head lower surface for distortion.

• Replace if damaged or if reject gauge enters valve guide.

2

Figure 14

6. Use Bushing Driver #19367, and press out valve guide bushing from combustion chamber (Figure 15).

Figure 12

3. If mounting surfaces are distorted more than

0.1 mm (0.004 in), the cylinder head must be replaced (Figure 13).

Figure 13

NOTE: It is not recommended that cylinder head mounting surfaces be resurfaced.

4. Inspect intake and exhaust manifold mounting surfaces in the same manner. Use same specifications as cylinder head.

5. Inspect valve guide bushing for damage. Check valve guide bushings for wear using Reject Gauge #19382, (A, Figure 14).

Figure 15

7. Check valve guide bushing OD. Then compare with the following specifications:

• Standard Bushing OD: 11.05 mm (0.435 in.)

• Replacement Bushing OD: 11.08 mm (0.4362 in.)

8. If bushing OD measurement indicates that a replacement bushing has already been installed, the cylinder head must be replaced.

9. Using Bushing Driver #19416, press in new valve guide bushing until tool bottoms on cylinder head (Figure 16).

12

2

Figure 16

10. Valve faces may be resurfaced to 30°. Check valve seat dimensions before resurfacing. (A, Figure 17) should be 0.05 - 0.06” (1.2 -

1.6mm) and (B) should be at least 0.0312”.

Figure 17

• Lap valves and seats with Valve Lapping Tool #19258 and Valve Lapping Compound #94150.

11. Valve seats may be reconditioned using Valve Seat Cutter #19446.

Figure 18

• Use a 45° (B) cutter to narrow seat from bottom.

• Use a 15° (C) cutter to narrow seat from top.

NOTE: If valve seat is loose or cracked, replace cylinder head.

12. Measure valve stem diameter at specified distance from end of valve (A, Figure 19).

• Replace IN if less than 0.2343 in. (5.952 mm).

• Replace EX if less than 0.2342 in. (5.948 mm).

NOTE: Inspect valve guide bushings first. If valve guides are worn, they must be replaced before refacing valve seats.

If valve seat is wider than 0.05 - 0.06” (1.2 - 1.6mm) (A, Figure 18), a narrowing cutter should be used to ensure that contact area of valve seat is centered on face of valve.

13

Figure 19

13. Inspect valve stem cap for wear (Figure 20). Replace if cap is worn recessed.

2

Figure 20

14. Inspect valve springs for squareness and free length (Figure 21).

Figure 21

• Replace if out of square more than 0.040 in. (1.0 mm).

• Replace if free length is less than 0.150 in. (29.2 mm).

14

Disassemble Rocker Arm Shaft

Remove snap rings (A, Figure 22) from ends of rocker arm shaft (B). Remove set screw (C) from center rocker arm support (D). Disassemble rocker arm assembly. Note position of rocker arms (E), thrust washers (F) and springs (G).

2

Figure 22

1. Check rotor arms and shaft (Figure 23).

Figure 23

2. Check rocker arm bearing. Replace if greater than 0.395 in. (10.03 mm).

3. Check rocker arm shaft. Replace if less than

0.392 in. (9.957 mm).

4. Check rocker arm studs for stripped threads and replace if required.

15

Assemble Rocker Arm Shaft

1. Oil all components before assembling.

2. Small grooves in rocker shaft (A) next to oil holes (B) must face down.

3. Assemble rocker arm (G) components, noting order of assembly shown in Figure 24.

2

Figure 24

4. Note position of three thrust washers (F), springs (D), snap rings (H)

5. Install set screw (C) in center rocker arm shaft support (E).

16

Assemble Cylinder Head

Cylinder Head Components (Figure 25)

• (A) - Cylinder Head

• (B) - Cylinder Head Gasket

• (C) - Valve Stem Cap

• (D) - Valve Spring Retainer Locks

• (E) - Valve Spring Retainer

• (F) - Valve Spring

• (G) - Valve

• (H) - Valve Spring Seat

• (J) - Valve Stem Seal

• (K) - Valve Guide

• (L) - Push Rod

• (M) - Rocker Arm Assembly

• (N) - Rocker Arm Stud

2

Figure 25

1. Install new valve stem seals (A, Figure 26). Oil inner surface and lip of seal before installing. Press seal on to valve guide bushing until it bottoms.

Figure 26

2. Install valve spring seats (Figure 27).

17

2

Figure 29

Figure 27

NOTE: Lightly coat valve stems with Valve Guide Lubricant #93963, before installing valves.

3. Install valves.

4. Install valve springs (Figure 28) with Valve Spring Compressor #19417.

Figure 28

NOTE: After installing valve spring retainer locks, tap valve spring retainer lightly with a soft hammer to ensure locks are seated.

Install Cylinder Head

1. Place cylinder head gasket over alignment dowels on cylinder block (Figure 29).

NOTE: Make sure coolant, oil passages, and head bolt holes are aligned.

2. Install cylinder head assembly.

3. Lubricate threads of cylinder head bolts with engine oil.

4. Torque head bolts in 10 ft. lbs. (13.0 Nm) increments in sequence shown (Figure 30).

Figure 30

NOTE: Current style head bolts are 9 mm diameter. Early style head bolts are 8 mm diameter. Torque specifications are different. Torque bolts to values listed in Section 14 - Engine Specifications.

5. Lubricate push rods with engine oil then install with recessed end up.

6. Install valve stem caps on valve stems. Install rocker arm assembly (Figure 31).

18

Figure 33

2

Figure 31

7. Install washers and torque nuts to values listed in Section 14 - Engine Specifications.

NOTE: Make sure rocker adjustments studs are seated in recessed end of push rods.

Install ignition coil bracket and ignition coils (Figure

32). Torque screws to values listed in Section 14 Engine Specifications.

8. Install ignition coil bracket and ignition coils (Figure 32). Torque screws to values listed in Section 14 - Engine Specifications.

10. Insert governor spring into original hole in governor lever.

NOTE: Normal spring position is in center hole in the governor lever (Figure 34).

NOTE: Governor spring must be installed in correct hole in governor control lever by engine model.

• Model 430400 - Top Hole

• Model 580400 - Bottom Hole

Figure 32

9. Install intake manifold with new gasket. Install governor link and spring (Figure 33). Torque screws to values listed in Section 14 - Engine Specifications.

19

Figure 34

11. Install exhaust manifold with new gasket (Figure 35). Torque screws to values listed in Section 14 - Engine Specifications.

2

Figure 35

12. Install water pump with new gasket (Figure

36). Torque screws and nuts to values listed in Section 14 - Engine Specifications.

Figure 36

13. Install water pump pulley (Figure 37). Install fan (if equipped). Torque screws to values listed in Section 14 - Engine Specifications.

Figure 38

NOTE: Belt deflection limit is 3/8-1/2 in./22 lb. (10.0-

12.0 mm/10 kg).

Adjust Valves

1. Before adjusting valves, make sure that the Number 1 cylinder is at Top Dead Center (TDC) - Compression Stroke (Figure 39).

Figure 39

Figure 37

14. Install V-belt (Figure 38). Install alternator adjusting bolt. Torque bolt to values listed in Section 14 - Engine Specifications.

20

2. Adjust valves and check (Figure 40).

• Valve Clearance (cold) IN and EX - 0.007 in. (0.18 mm).

• Torque adjusting screws and jam nuts to values listed in Section 14 - Engine Specifications.

Figure 40

3. With Number 1 piston at TDC of compression stroke, check and adjust valve clearances for cylinders (Figure 41).

4. Rotate crankshaft one complete turn 360° clockwise to check and adjust remaining valves.

5. Install valve cover (Figure 41).Torque cover nuts to values listed in Section 14 - Engine Specifications.

2

Figure 41

6. Install spark plugs. Torque spark plugs to values listed in Section 14 - Engine Specifications.

21

2

22

SECTION 3 - GOVERNOR, TIMING GEARS, AND GEAR CASE

REMOVE TIMING GEAR COVER AND GEARS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -24

INSPECT GEARS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -25

REMOVE GEAR CASE- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -26

DISASSEMBLE GOVERNOR SHAFT ASSEMBLY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -27

REPLACE TIMING GEAR COVER OIL SEAL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -27

ASSEMBLE GOVERNOR SHAFT ASSEMBLY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -27

ASSEMBLE TIMING GEAR CASE AND GEARS- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -28

ADJUST GOVERNOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -31

TROUBLESHOOTING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -31

ELECTRONIC GOVERNOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -32

INSPECT GOVERNOR ACTUATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -33

3

REMOVE GOVERNOR ACTUATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -33

INSTALL GOVERNOR ACTUATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -33

23

3

TIMING GEARS, GEAR CASE, ELECTRONIC GOVERNOR

3

Remove Timing Gear Cover and Gears

NOTE: Make sure the Number 1 cylinder is at Top

Dead Center (TDC), compression stroke. See Section 2.

1. Remove V-belt and fan (if equipped).

2. Drain oil from engine.

NOTE: Before removing governor spring, note hole position of governor spring in governor lever.

3. Remove governor link spring (A, Figure 1)

and governor link from carburetor.

4. Remove governor spring from governor lever (B).

5. Loosen nut (C) and remove governor lever from governor shaft.

24

Figure 1

6. Remove oil pan screws and nuts.

7. Remove oil pan and discard gasket.

8. Remove oil pick-up tube (A, Figure 2) and strainer. Discard gasket.

Figure 2

9. Remove bell housing adapter screw (if equipped) and install Flywheel Holder #19418 (A, Figure 3).

3

Figure 4

12. Remove governor gear (A, Figure 5), governor cup (B), E-ring (C), governor gear (D), and thrust washer (E).

13. Remove oil pump drive gear (F).

NOTE: Leave tool installed.

10. Remove crankshaft pulley using Tool #19420 (B).

Figure 3

11. Remove trigger (A, Figure 4) and wire. Remove timing gear cover (B) and discard timing gear gasket.

Figure 5

14. Check governor gear and oil pump drive gear for damaged teeth.

Inspect Gears

1. Inspect gear teeth for wear or damage.

2. Check gear back lash between idler gear (A, Figure 6) and crankshaft gear (B) using a dial indicator.

• Set tip of indicator on gear tooth, then rock idler gear back and forth noting indicator reading.

• Crankshaft must not turn while checking.

25

7. If gears are worn, it is recommended that they be replaced as a set.

3

Figure 6

3. If back lash exceeds 0.008 in. (0.2 mm) check idler gear bearing and shaft for wear (Figure 7).

Reject dimensions for Idler Gear:

• ID - 0.345 in. (34.17 mm)

• OD - 1.335 in. (33.91 mm)

Figure 7

3

Figure 8

Remove Gear Case

1. Remove three screws (A, Figure 9) and camshaft retainer.

2. Remove remaining five screws (B).

4. If idler gear bearing and shaft are within specification, replace with new idler gear and recheck.

5. If back lash exceeds 0.008 in. (0.2 mm) with NEW idler gear, crankshaft gear is worn.

NOTE: If crankshaft gear is worn the crankshaft must be replaced.

6. Hold idler gear and check gear backlash between camshaft timing gear (A, Figure 8) and idler gear (B) using a dial indicator.

NOTE: Idler gear must not turn while checking.

26

Figure 9

3. Remove timing gear case and discard gasket.

4. Remove oil pump rotor (Figure 10) from cylinder block.

Figure 12

3

Figure 10

Disassemble Governor Shaft Assembly

1. Remove cotter pin (A, Figure 11) and washer (B). Discard cotter pin.

2. Remove screws (C) and governor paddle (D) using Torx® Driver #19445. Discard screws.

NOTE: Governor paddle screws are Torx® tamper proof screws.

3. Remove shaft (E) and spacer (F).

4. Remove and discard oil seal (G).

Figure 11

Replace Timing Gear Cover Oil Seal

1. Drive out oil seal.

2. Use Seal Driver #19423 to install new oil seal (Figure 12).

Assemble Governor Shaft Assembly

1. Install thrust washer (A, Figure 13) on shaft followed by the governor gear (B), E-ring (C), and governor cup (D).

Figure 13

NOTE: Lubricate governor shaft with engine oil before installing.

2. Install new oil seal (A, Figure 14) with seal lips in.

3. Install governor shaft (B) and spacer (C).

4. Install governor paddle (D) using new screws (E). Use Torx® Driver #19445. Torque to values listed in Section 14 - Engine Specifications.

5. Install washer (F) and new cotter pin (G).

NOTE: Governor shaft must rotate freely.

27

3

Figure 14

Assemble Timing Gear Case and Gears

1. Clean and lubricate oil pump rotor (A, Figure

15) with engine oil and install on cylinder block.

NOTE: ID mark (B) on rotor must face cylinder block.

Figure 16

NOTE: It may be necessary to rotate oil pump drive to engage oil pump rotors.

NOTE: Position camshaft retainer so that the center hole does not interfere with the camshaft.

3. Note position, length, and number of screws (Figure 16).

• M6 x 1.1 in. (M6 x 28 mm): 4 (A)

• M6 x 0.7 in. (M6 x 18 mm): 3 (B)

• M6 x 0.6 in. (M6 x 16 mm): 1 (C)

4. Torque screws to values listed in Section 14 Engine Specifications.

5. Make sure crankshaft key is at the 12 o’clock position (A, Figure 17).

Figure 15

2. Install timing gear case with new gasket. Install camshaft retainer (A, Figure 16).

28

Figure 17

6. Assemble idler gear shaft with arrow up (A, Figure 18).

Figure 18

3

Engine models 430000 and 580000 built after date code 990111007 are equipped with right angle helical timing gears. Timing marks are identified by letters (A, AA, B, BB, etc.), instead of numbers. The timing procedure is the same.

7. With crankshaft key at the12 o’clock position, assemble idler gear so that timing mark 11 (AA) is aligned with timing mark 1 (A) on crankshaft gear, timing mark 22 (BB) is aligned with timing mark 2 (B) on camshaft gear (Figure 19).

Figure 20

10. Install timing gear cover with new gasket. Note position, length, and number of screws (Figure 21). Torque screws to values listed in Section 14 - Engine Specifications.

• M6 x 2.5 in. (M6 x 65 mm): 2 (A)

• M6 x 2.1 in. (M6 x 55 mm): 3 (B)

• M6 x 1.1 in. (M6 x 30 mm): 7 (C)

• M6 Nut: 2 (D)

Figure 19

8. Install oil pump gear.

9. Torque screws to values listed in Section 14 Engine Specifications. Camshaft gear (A, Figure 20), idler gear (B), and oil pump gear (C).

29

Figure 21

11. Install crankshaft pulley with timing mark at 12 o’clock position (No. 1 cylinder) (Figure

22).

NOTE: Ensure alignment pin in crankshaft gear is seated in hole in pulley.

12. Remove flywheel holder (A) and install trigger assembly and wire (B).

3

Figure 22

13. Install oil pick-up tube and strainer with new gasket.

14. Apply a small bead of Permatex® No. 2 or other similar sealant (A, Figure 23).

3

Figure 24

19. Insert governor spring into original hole in governor lever.

NOTICE: Governor spring must be installed in correct hole in governor control lever by engine model (Figure 25).

• Model 430400 - Top Hole (A)

• Model 580400 - Bottom Hole (B)

Figure 23

15. Install oil pan with new gasket. Torque screws and nuts to values shown in Section 14 - Engine Specifications.

16. Install V-belt and fan (if equipped).

17. Install governor lever (A, Figure 24) on to governor shaft. Do not tighten governor nut at this time.

18. Install governor link with spring (B).

30

Figure 25

Adjust Governor

1. Move governor control lever (A, Figure 26) up to end of travel and hold in this position (throttle wide open).

2. Rotate governor shaft (B) clockwise to end of travel.

3. Torque governor nut (C) to value listed in Section 14 - Engine Specifications.

3

Figure 27

• If dimension is greater than 1 mm, perform governor adjustment.

• If engine continues to hunt at top no load speed, decrease governor sensitivity by moving governor spring to next hole on governor lever (Figure 28).

Figure 26

Troubleshooting

If engine hunts at top no load speed, check governor adjustment as follows:

1. Stop engine.

2. Move equipment control to “FAST” position.

3. Disconnect governor link spring and link.

4. Rotate throttle wide open position.

NOTE: Position of governor link must be within 1 mm of center of hole in throttle (Figure 27).

NOTE: Moving spring away from governor shaft pivot point decreases sensitivity. Moving spring towards governor shaft pivot point increases sensitivity.

Figure 28

31

Electronic Governor

The ignition module and related wiring for the electronic governor is supplied by the equipment manufacturer.

NOTE: Engines equipped with an electronic governor do not have mechanical governor components.

3

A - Governor Actuator B - Governor Link C - Governor Link Spring D - Wiring Harness

32

Inspect Governor Actuator

1. Disconnect harness at connector (A, Figure

29).

2. Touch test leads (B) to terminals of a known good 12 volt battery.

• Actuator lever (C) should quickly move the throttle to a wide open position (D).

3. Remove test leads from battery terminals.

• Actuator lever should quickly move throttle lever to idler position.

4. Replace actuator if not to specification.

Install Governor Actuator

1. Assemble governor link spring and link to actuator lever (Figure 31).

NOTE: Open ends of spring must face cylinder head.

2. Assemble actuator to mounting bracket loosely. Do not tighten screws.

3

Figure 31

Figure 29

Remove Governor Actuator

1. Disconnect governor link spring and link (A, Figure 30).

2. Remove two screws (B) and actuator (C).

3. Rotate throttle lever clockwise to end of travel and hold in this position.

4. Slide actuator until governor link is positioned slightly to rear of hole in throttle lever bushing (Figure 32).

5. Torque mounting screws to values listed in Section 14 - Engine Specifications.

6. Assemble governor link and spring to throttle lever.

Figure 30

33

Figure 32

3

34

SECTION 4 - FLYWHEEL AND REAR SEAL RETAINER

REMOVE OIL PAN AND FLYWHEEL- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -36

REMOVE REAR SEAL RETAINER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -36

REPLACE OIL SEAL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -36

INSTALL REAL SEAL RETAINER AND FLYWHEEL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -37

INSTALL OIL PAN - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -37

4

35

4

Removing Pan and Flywheel

1. Drain oil from engine.

2. Remove oil pan screws and nuts (Figure 1).

3. Remove oil pan and discard gasket.

Figure 1

4. Install Flywheel Holder #19418 (A, Figure 2). Remove flywheel screws and flywheel.

Remove Rear Seal Retainer

1. Remove rear seal retainer and discard gasket (Figure 3).

Figure 3

Replacing Oil Seal

1. Remove oil seal (Figure 4).

Figure 2

5. Inspect flywheel for cracks or damage. Inspect flywheel ring gear for worn, chipped, or cracked teeth.

NOTE: If ring gear is worn or damaged, the flywheel must be replaced.

36

Figure 4

2. Lubricate outside diameter of oil seal.

3. Using a Seal Driver #19424, install new seal (Figure 5).

4

Figure 5

Installing Rear Seal Retainer and Flywheel

1. Install real seal retainer with new gasket (Figure 6). Torque screws to values listed in Section 14 - Engine Specifications.

Figure 6

Figure 7

3. Torque flywheel screws to values listed in Section 14 - Engine Specifications.

4. Remove flywheel holder.

Install Oil Pan

1. Install oil pan with new gasket.

2. All small bead of Permatex® No. 2 or similar sealant to crankcase areas (A, Figure 8).

2. Install flywheel (Figure 7).

NOTE: Apply Permatex® No. 2 or similar sealant to flywheel screws.

37

Figure 8

3. Torque screws and nuts to values listed in Section 14 - Engine Specifications.

4

38

SECTION 5 - CYLINDER BLOCK DISASSEMBLY

CYLINDER BLOCK

CYLINDER BLOCK DISASSEMBLY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -40

5

39

5

Cylinder Block Disassembly

An automotive type engine stand is recommended when complete engine disassembly is required. See drawings below for dimensions to make an engine stand mounting fixture. The engine stand shown below is manufactured by Snap-On®.

40

1. Remove cylinder head. See Section 2.

2. Remove oil pan, timing cover, gears, and case. See Section 3.

3. Remove flywheel and rear seal retainer. See Section 4.

4. Remove starter motor (Figure 1).

Figure 1

5. Remove alternator bracket and alternator (Figure 2).

5

Figure 3

7. Remove camshaft (Figure 4).

NOTE: Use care when removing camshaft to prevent damaging cam bearing, journals, and lobes.

Figure 2

6. Remove valve lifters (Figure 3).

NOTE: Number lifters so that they may be reinstalled in the same position.

41

Figure 4

8. Remove oil pick-up tube and strainer (Figure

5). Discard gasket.

5

NOTE: Main bearing caps are numbered 1 through

4.

Figure 5

9. Remove connecting rod and piston assemblies (Figure 6).

NOTE: Remove carbon or ridge from cylinder and number connecting rod/piston assemblies before removing from cylinders.

• Remove connecting rod cap with lower bearing.

• Push connecting rod and piston out through top of cylinder.

• Reassemble connecting rod cap to connecting rod to prevent interchanging components.

Figure 7

11. Remove crankshaft (A, Figure 8).

• Remove crankshaft thrust washers (#3 main bearing).

• Remove upper main bearings from saddles and place with respective bearing caps.

Figure 8

Figure 6

10. Remove crankshaft main bearing caps, keeping main bearings with their respective caps (Figure 7).

42

SECTION 6 - CYLINDER BLOCK INSPECTION AND REPAIR

CHECK CYLINDER BLOCK - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -44

CHECK CYLINDER BORE FOR WEAR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -44

REPLACE CAMSHAFT BEARINGS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -45

REPLACE CAMSHAFT PLUG - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -45

6

43

Inspect Cylinder Block

1. Remove all traces of sealant and gasket material from mounting surfaces. Inspect cylinder block for damage, cracks, and stripped threads.

2. Inspect cylinder block deck for distortion (Figure 1).

• Distortion Limit - 0.003 in. (0.08 mm).

6

Figure 1

3. If cylinder block exceeds limits shown, it may be resurfaced (Figure 2).

6

Figure 3

NOTE: Always resize to exactly 0.010 in. (0.25mm) over standard bore size. If this is done accurately, the service oversize rings and pistons will fit perfectly and proper clearances will be maintained.

3. Check valve lifter bore (Figure 4).

• Standard Dimension - 0.709 in. (18.02 mm)

• Reject Dimension - 0.711 in. (18.05 mm)

4. Check valve lifter (Figure 4).

• Standard Dimension - 0.708 in. (17.98 mm)

• Reject Dimension - 0.705 in. (17.91 mm)

Figure 2

Inspect Cylinder Bore for Wear:

1. Measure cylinder bore in 6 points at right angles (Figure 3).

2. If cylinder bore is worn more than 0.003 in. (0.075 mm) or more than 0.0015 in. (0.035 mm) out of round, it must be resized.

44

Figure 4

5. Check Camshaft bearing (Figure 5).

• Replace if greater than 1.42 in. (36.06 mm)

Figure 5

Replace Camshaft Bearing

1. Using Camshaft Bearing Puller #19421, remove camshaft bearing (Figure 6).

Replace Camshaft Plug

1. Remove rear camshaft plug (Figure 8).

NOTICE: Use a wood dowel or brass rod to prevent damage to the camshaft bearing.

6

Figure 8

2. Using Camshaft Bearing Driver #19422, install new camshaft plug flush with cylinder block (Figure 9).

Figure 6

2. Using Camshaft Bearing Driver #19422. install camshaft bearing (Figure 7).

Figure 7

45

Figure 9

NOTE: If cylinder block is being resized, the following parts should be removed so that the cylinder block can be thoroughly cleaned.

3. Remove oil pressure switch (A, Figure 10), water gallery plug (B), and oil filter adapter (C).

6

Figure 10

4. Remove timing gear oil nozzle (A, Figure 11).

Figure 11

5. When reinstalling oil nozzle, oil hole must be positioned at a 45° angle, pointing towards the idler gear (A, Figure 12).

Figure 12

46

SECTION 7 - CRANKSHAFT, CAMSHAFT AND BEARINGS

INSPECT CRANKSHAFT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -48

CHECK MAIN BEARING CLEARANCES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -49

CHECK CONNECTING ROD BEARING CLEARANCES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -50

CHECK CRANKSHAFT END PLAY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -50

INSPECT CAMSHAFT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -51

7

47

Inspect Crankshaft

1. Inspect crankshaft journals for grooves or signs of scoring. If found, crankshaft must be re-ground or replaced.

2. Check the main bearing and crankpin journals for wear and taper (Figure 1).

7

Figure 1

• Standard Size (Main) - 1.6525 - 1.6535 in. (41.976 - 42.000 mm)

• Standard Size (Crankpin) - 1.4557 - 1.4567 in. (36.976 - 37.000 mm)

• Maximum out of round and taper - 0.0008 in. (0.02 mm)

3. If crankshaft journals are not within specification, the crankshaft may be reground and 0.010 in. (0.25 mm) undersize bearings installed. See illustrated parts list for part numbers.

4. Check the crankshaft for run-out at #3 main bearing journal (Figure 2).

7

Figure 2

• Maximum Run-out - 0.0023 in. (0.06 mm)

NOTE: If run-out exceeds specification shown, the crankshaft must be replaced.

5. Check crankshaft timing gear teeth for damage (Figure 3). If timing gear teeth are damaged or worn, the crankshaft must be replaced.

NOTE: See Section 3 for procedure to check crankshaft timing gear for wear.

48

Figure 3

Check Main Bearing Clearances

NOTE: If main bearings show signs of flaking or

scoring, bearings must be replaced.

NOTE: Main bearing saddles in cylinder block, main bearing caps, main bearings, and crankshaft journals must be clean and free of oil.

1. With upper main bearings installed, install crankshaft.

2. Lay a strip of plastigage lengthwise on journal (A, Figure 4).

NOTE: Do not lay plastigage across hole in crankshaft journal.

Figure 4

7

Figure 5

4. Remove the bearing cap. Measure the plastigage at its widest point (A, Figure 6). If the clearance is not within specification, replace the bearings.

• Standard Main Bearing Clearance -

0.0008 - 0.0017 in. (0.020 - 0.044 mm)

• Reject Main Bearing Clearance - 0.0028 in. (0.07 mm)

3. Assemble main bearing cap with bearing (Figure 5) and torque to values listed in Section 14 - Engine Specifications.

NOTE: Do not allow crankshaft to rotate.

Figure 6

5. Repeat procedure for each main bearing.

49

7

Check Connecting Rod Bearing Clearances

NOTE: If connecting rod bearings show signs of

flaking or scoring, bearings must be replaced.

NOTE: Connecting rod bearings and crankpin journals must be clean and free of oil.

1. With upper bearing assembled to the connecting rod, install the connecting rod.

2. Lay a strip of plastigage lengthwise on journal (A, Figure 7).

NOTE: Do not lay plastigage across hole in crankshaft journal.

4. Remove the connecting rod cap. Measure the plastigage at its widest point (A, Figure 9). If the clearance is not within specification, replace the bearings.

• Standard Main Bearing Clearance -

0.0008 - 0.0017 in. (0.020 - 0.044 mm)

• Reject Main Bearing Clearance - 0.0028 in. (0.07 mm)

7

Figure 9

Figure 7

3. Assemble connecting rod cap with bearing and torque to values listed in Section 14 (Figure 8).

NOTE: Do not allow crankshaft to rotate.

5. Repeat procedure for each main bearing.

Check Crankshaft End Play

1. With thrust washers installed, check crankshaft end play at #3 main bearing (Figure 10).

• Standard Crankshaft End Play - 0.0008 -

0.009 in. (0.020 - 0.23 mm)

• Limit Crankshaft End Play - 0.012 in. (0.30 mm)

2. If end play exceeds limit,0.005 in. (0.13 mm), over size thrust washers are available. See illustrated parts list for part numbers.

Figure 8

50

Figure 12

7

Figure 10

Inspect Camshaft

1. Measure camshaft lobe height (Figure 11). If lobes are not to specification, replace the camshaft.

• Standard Intake/Exhaust - 1.183 - 1.186 in. (30.065 - 30.135 mm)

• Reject Intake/Exhaust - 1.179 in. (29.965 mm)

Figure 11

3. Measure camshaft run-out (Figure 13).

• Maximum Run-out - 0.0012 in. (0.03 mm)

4. If a run-out exceeds specification, the camshaft must be replaced.

Figure 13

2. Measure camshaft journals (Figure 12).

51

7

52

SECTION 8 - PISTON, RINGS AND CONNECTING ROD

DISASSEMBLE PISTON AND CONNECTING ROD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -54

INSPECT PISTONS AND RINGS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -54

CHECK PISTON PIN AND CONNECTING ROD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -55

ASSEMBLE PISTON AND CONNECTING ROD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -56

ASSEMBLE PISTON RINGS TO PISTON - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -56

8

53

Disassemble Piston and Connecting Rod

1. Remove compression rings using Ring Expander #19340 (Figure 1).

8

Figure 1

2. Oil ring may be removed by hand by spiraling top scraper into center ring groove, then into top groove and off piston. Repeat for bottom scraper, then remove expander.

3. Disassemble piston from connecting rod using Piston Pin Fixture #19419.

NOTE: Piston pin stop (A, Figure 2) must be removed from support (B) when disassembling piston and connecting rod.

If the cylinder bore is to be resized there is no reason to check the piston as a new oversized piston will be used.

If the cylinder is not going to be resized, and the piston shows no signs of scoring, the piston should be checked.

1. Check side clearance of ring grooves using NEW rings (A, Figure 3). If a 0.0045 in. (0.11 mm) feeler gauge can be inserted, the ring groove is worn. The piston must be replaced.

Figure 3

4. Insert threaded driver (C) through piston pin from FRONT side of piston and thread into pilot.

5. Place piston with driver onto support with arrow on piston facing up.

6. Press out piston pin.

Figure 2

2. Check ring end gap (Figure 4).

3. Clean carbon from end of rings and insert approximately 1.0 in. (25 mm) into cylinder.

Figure 4

4. Check piston pin bore (Figure 5).

Inspect Piston and Rings

54

3. Check crankpin bearing end of connecting rod (Figure 8).

8

Figure 5

• Replace if greater than 0.710 in. (18.03 mm) or 0.0004 in. (0.01 mm) out of round.

Check Piston Pin and Connecting Rod

1. Check piston pin (Figure 6).

Figure 6

• Replace if less than 0.708 in. (17.98 mm) or 0.0004 in. (0.01 mm) out of round.

2. Check piston pin bearing (Figure 7).

Figure 8

• Maximum out of round: 0.0008 in. (0.02 mm)

• If out of round exceeds specification shown, the connecting rod must be replaced.

4. Check for bent or twisted connecting rod (Figure 9).

Figure 9

NOTE: Thrust faces must be free of any burrs or nicks or connecting rod will not lay flat on surface plate.

• With connecting rod on a surface plate, any distortion will be evident by a rocking motion.

• If a 0.002 in. (0.05 mm) feeler gauge can be inserted at piston pin end of connecting rod, the rod must be replaced.

Figure 7

• Replace if greater than 17.98 mm (0.708 in.) or 0.01 mm (0.004 in.) out of round.

55

8

Assemble Piston and Connecting Rod

1. Assemble piston to connecting rod using Piston Pin Fixture #19419.

NOTE: Arrow on piston (A, Figure 10) and ID mark (B) on rod must face same side.

2. Lubricate piston pin with engine oil. Then, insert threaded driver (C) through piston pin (D) and thread into pilot (E).

3. With arrow on piston and ID mark on rod facing up, insert pilot through piston and connecting rod.

Assemble Piston Rings to Piston

1. Install oil ring expander first.

2. Spiral bottom oil control ring into top ring groove, center ring groove, and then into position below expander (Figure 12).

3. Repeat for upper oil control ring.

Figure 12

Figure 10

4. Insert piston pin stop (A, Figure 11) in bottom of piston support (B).

Figure 11

5. With arrow on piston up, place assembly onto support.

6. Press in piston pin until pilot bottoms on stop.

7. After assembly, make sure the piston rotates freely on connecting rod.

4. Using ring expander, install center compression ring then, top compression ring with ID marks up (Figure 13).

5. Stagger ring end gaps.

6. Rotate oil control ring ends 180° from each other.

Figure 13

56

SECTION 9 - CYLINDER BLOCK ASSEMBLY

INSTALL CRANKSHAFT- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -58

INSTALL PISTONS AND CONNECTING RODS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -59

GENERAL ASSEMBLY- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -59

INSTALL TIMING GEAR CASE, CAMSHAFT, AND GEARS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -60

INSTALL OIL PAN - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -62

INSTALL ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -62

GENERAL ASSEMBLY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -62

9

57

9

Install Crankshaft

1. Install main bearings in cylinder block.

NOTE: Upper bearing has an oil groove (A, Figure 1) and oil holes (B).

Figure 1

2. Install upper main bearings in their respective saddles.

3. Ensure bearing is seated in saddle and tang in bearing is aligned with notch in saddle. Lubricate bearings with engine oil.

4. Install lower main bearings in bearing caps (Figure 2).

Figure 3

9. Install main bearing caps. Lubricate threads of screws with engine oil.

10. Install bearing caps in their respective positions with arrows facing front.

11. Start with Number 3 bearing cap (Figure 4) and torque bearing caps one at a time in sequence shown to values listed in Section 14 - Engine Specifications.

Figure 2

5. Be sure bearing is seated in bearing cap and tang in bearing is aligned with notch in bearing cap.

6. Lubricate bearings with engine oil.

7. Install crankshaft with gear facing front of cylinder block (Figure 3). Take care not to damage journals or bearings.

8. Install crankshaft shims on No. 3 main bearings web with grooves facing out. Lubricate journals with engine oil.

58

Figure 4

12. Recheck crankshaft end play.

• Crankshaft end play - 0.001 - 0.009 in. (0.025 - 0.23 mm)

NOTE: After torquing bearing cap, make sure crankshaft rotates freely before proceeding to next bearing cap.

Install Pistons and Connecting Rods

1. Install connecting rod bearings. Be sure tang on bearing is seated in notch (A, Figure 5) in connecting rod and cap.

2. Install a piece of vinyl tubing (B) over each connecting rod screw to prevent damage to screw threads or crankpin when installing piston and connecting rod.

Figure 5

3. Rotate crankshaft so that crankpin is at bottom of stroke. Lubricate cylinder walls, pistons and rings, bearings, and crankpins.

4. Using Tool Ring Compressor #19070, install piston and connecting rod assemblies with arrow on piston facing front.

5. Install connecting rod cap with ID mark (A, Figure 6) facing front. Lubricate threads and torque nuts to values listed in Section 14

- Engine Specifications.

General Assembly

1. Install gasket, oil pick-up tube and strainer (Figure 7). Torque screws to values listed in Section 14 - Engine Specifications.

9

Figure 7

2. Install gasket and rear seal retainer (A, Figure 8). Torque screws to values listed in Section 14 - Engine Specifications.

3. Install starter motor (B) and torque screws to values listed in Section 14 - Engine Specifications.

Figure 6

NOTE: After torquing rod cap, make sure crankshaft rotates freely before proceeding to next cylinder.

59

Figure 8

4. Install flywheel and flywheel holder (A, Figure 9).

5. Apply sealant to flywheel screws and torque to values listed in Section 14 - Engine Specifications.

9

Figure 9

Figure 11

Install Timing Gear Case, Camshaft, and Gears

1. Lubricate oil pump rotor (A, Figure 10) with engine oil and install in cylinder block.

• ID mark (B) on rotor must face cylinder block.

Figure 10

2. Install timing gear case with new gasket (Figure 11).It may be necessary to rotate oil pump drive to engage oil pump rotors.

3. Note position, length, and quantity of screws as shown.

• M6 x 1.1 in. (M6 x 28mm): 4 (A).

• M6 x 1.5 in. (M6 x 16mm): 1 (B).

4. Torque screws to values listed in Section 14 Engine Specifications.

5. Lubricate and install camshaft in cylinder block. Take care not to damage lobes or cam bearing.

6. Install camshaft retainer (A, Figure 12).

7. Install three screws (B) and torque to values listed in Section 14 - Engine Specifications.

NOTE: Position camshaft retainer so that the center hole does not interfere with camshaft.

Figure 12

8. Rotate crankshaft so that they key is at the 12 o’clock position (A, Figure 13).

60

9

Figure 13

9. Assemble idler gear shaft (A, Figure 14) with ID mark (B) up.

Figure 14

Engine models 430000 and 580000 after date code 990111007 are equipped with right angle helical timing gears. Timing marks are identified by letters (A, AA, B, BB, etc.), instead of numbers. The timing procedure is the same.

10. With the crankshaft key at the 12 o’clock position, assemble idler gear so that timing mark 11 (AA) is aligned with timing mark 1 (A) in crankshaft gear, timing mark 22 (BB) is aligned with timing mark 2 (B) on camshaft gear (Figure 15).

Figure 15

11. Install camshaft gear (A, Figure 16), idler gear (B), and oil pump gear (C). Torque screws to values listed in Section 14 - Engine Specifications.

Figure 16

12. Install timing gear cover with new gasket.

13. Note position, length, and number of screws (Figure 17).

• M6 x 2.5 in. (M6 x 65 mm): 2 (A).

• M6 x 2.1 in. (M6 x 55 mm): 3 (B).

• M6 x 1.1 in. (M6 x 30 mm): 7 (C).

• M6 Nuts: 2 (D).

61

9

Figure 17

14. Torque screws to values listed in Section 14 Engine Specifications.

15. Install crankshaft pulley with timing mark at 12 o'clock position (Number 1 cylinder).

NOTE: Be sure alignment pin in crankshaft gear is seated in hole in pulley.

16. Torque screw to values listed in Section 14 Engine Specifications.

17. Remove flywheel holder.

18. Install trigger assembly (A, Figure 18) and wire.

Figure 19

3. Torque screws to values listed in Section 14 Engine Specifications.

Install Alternator

1. Install alternator bracket and alternator (Figure 20).

Figure 20

2. Torque screws to values listed in Section 14 Engine Specifications.

Figure 18

Install Oil Pan

1. Install oil pan with new gasket.

2. Apply a small bead of sealant to crankcase areas (A, Figure 19).

62

General Assembly

1. Lubricate tappets with engine oil and install in cylinder block.

2. See Section 2 for installation of cylinder head and related components.

3. See Section 3 for governor adjustment procedure.

SECTION 10 - CARBURETOR AND RELATED COMPONENTS

MANUAL CHOKE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -66

REMOVE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -66

DISASSEMBLE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -66

CLEAN CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -68

INSPECT CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -68

CHECK THROTTLE, CHOKE SHAFT, AND BODY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -68

ASSEMBLE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -69

INSTALL THROTTLE SHAFT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -69

INSTALL CHOKE VALVE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -69

INSTALL FLOAT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -70

INSTALL CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -70

10

INITIAL CARBURETOR ADJUSTMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -71

FINAL CARBURETOR ADJUSTMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -71

AUTOMATIC CHOKE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -73

REMOVE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -73

DISASSEMBLE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -73

CLEAN CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -75

INSPECT CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -75

CHECK THROTTLE, CHOKE SHAFT, AND BODY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -76

ASSEMBLE CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -76

CHECK VACUUM CHOKE BREAK - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -78

ADJUST CHOKE PRE-LOAD LEVER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -78

CHECK P.T.C. HEATER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -79

INSTALL CARBURETOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -79

INSTALL VACUUM LIMITER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -79

63

INITIAL CARBURETOR ADJUSTMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -280

FINAL CARBURETOR ADJUSTMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 280

ELECTRIC FUEL PUMP - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -81

CHECK FUEL PUMP OUTPUT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -82

TEST EQUIPMENT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -82

10

TEST FUEL PUMP WIRING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -82

ANTI-AFTERFIRE SOLENOID - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -83

TEST ANTI-AFTERFIRE SOLENOID - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -83

TEST SOLENOID- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -83

FUEL FILTER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -84

CARBURETOR MAIN JETS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -84

ELECTRONIC FUEL INJECTION SYSTEM - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -85

EFI COMPONENTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -85

TROUBLESHOOTING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -89

ELECTRICAL SYSTEM - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -89

FAULT CODES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -90

FLASH CODE ON MIL INDICATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -91

TROUBLESHOOTING CHARTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -92

64

10

MANUAL CHOKE CARBURETOR

AUTOMATIC CHOKE CARBURETOR

65

10

Manual Choke Carburetor

Remove Carburetor

1. Disconnect fuel line (A, Figure 1).

2. Remove air cleaner tube from carburetor air horn. Disconnect fuel solenoid wire, if equipped.

Figure 1

6. Remove choke link (A, Figure 3) from choke lever.

Figure 3

7. Remove nuts, air horn (A, Figure 4), carburetor (B), and insulator (C). Discard gaskets (D).

3. Unhook governor link spring (B) from throttle lever and disconnect governor link (C).

4. Disconnect choke link (D) at choke lever. Proceed to Step 7.

NOTE: Early style choke links were manufactured with a “Z” bend (Figure 3). To remove choke link the governor control bracket must be removed. Proceed to Steps 5 and 6.

5. Disconnect governor spring (A, Figure 2). Remove two screws and governor control bracket (B) from intake manifold.

Figure 4

Disassemble Carburetor

1. Remove anti-afterfire solenoid (A, Figure 5), bowl screw (B), washer (C), and carburetor bowl (D).

Figure 2

66

Figure 5

4. Remove fixed high speed jet (A, Figure 8).

5. Remove emulsion tube (B).

10

2. Drive out float hinge pin (A, Figure 6) from choke plate side of carburetor (B) with a small punch. Remove float (C) and fuel inlet valve (D).

Figure 6

3. Remove carburetor bowl gasket (A, Figure 7).

Figure 8

NOTE: Consult the illustrated parts list for correct part number for special high altitude jet, if required.

6. Remove idle jet (A, Figure 9).

Figure 9

7. If idle mixture screw (A, Figure 10) is equipped with adjustment limiter cap, use pliers to remove it before removing idle mixture valve.

8. Remove idle mixture screw and spring (B).

Figure 7

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10

Figure 10

9. Remove screw and choke plate (A, Figure 11).

10. Remove choke shaft (B) and spring (C).

Figure 11

NOTE: If engine is equipped with an electronic governor system, DO NOT remove throttle plate or throttle shaft. This is a precision assembly and should not be disassembled.

Figure 12

Clean Carburetor

Remove gasket material from mounting surfaces. Gummy or dirty carburetors should be cleaned in a carburetor cleaner. DO NOT soak rubber, neoprene, or plastic parts in cleaner.

NOTICE: If engine is equipped with an electronic governor system, DO NOT clean carburetor in carburetor cleaner. The carburetor is equipped with sealed ball bearings for the throttle shaft, which will be damaged if the carburetor is immersed in carburetor cleaner. Ball bearings are not replaceable.

Inspect Carburetor

Inspect all parts for wear, cracks, nicks, and burrs. Inspect float for leaks. Replace all damaged parts.

Inspect Throttle, Choke Shaft, and Body for Wear

1. Lay carburetor on flat surface and check throttle and choke shaft clearance (Figure 13).

11. If engine is not equipped with an electronic governor, proceed to step 12.

12. Mark throttle plate (A, Figure 12) before removing so that it may be reinstalled in the same position. Sides of throttle plate are beveled.

13. Remove two screws, throttle plate, throttle shaft (B) with collar (C) and seal (D). Discard seal.

68

NOTE: Throttle shaft and choke shaft clearance must not exceed 0.010 in. (.25 mm).

10

Figure 13

2. Inspect throttle shaft and choke shaft for wear (Figure 14).

Figure 14

• Replace if worn.

• If carburetor body is worn, replace carburetor.

Assemble Carburetor

Figure 15

Install Choke Valve

1. Assemble spring (A, Figure 16) to choke shaft (B) and insert in body.

2. Rotate shaft clockwise to pre-load spring.

3. Install choke plate with hole facing fuel inlet side of body (C).

Figure 16

4. Assemble the emulsion tube (A, Figure 17), the fixed high speed jet (B), and the idle jet (C).

NOTE: When assembling carburetor, use new seals and gaskets.

Install Throttle Shaft

1. Install seal (A, Figure 15) with grooved side out.

2. Assemble collar (B) to throttle shaft and insert in body.

3. Install throttle plate and screws (C).

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10

4. Install idle mixture screw (A, Figure 20) and spring (B).

Figure 17

Install Float

1. Assemble inlet valve (A, Figure 18) to float.

2. Install float hinge pin (B) from throttle side of carburetor.

Figure 18

3. Install gasket (A, Figure 19) and float bowl (B).

Figure 20

NOTE: DO NOT tighten idle mixture screw.

Install Carburetor

1. Assemble insulator (A, Figure 21) with gaskets, carburetor (B), and air horn (C) with gasket (D) to intake manifold.

Figure 21

Figure 19

70

2. Torque nuts to values listed in Section 14 Engine Specifications.

3. Install governor link, spring, and choke link.

NOTE: Proceed to Step 5 if choke link is early style with “Z” bend.

4. Reinstall air cleaner tube and fuel line.

5. Install choke link. Assemble governor control bracket to intake manifold. Torque screws to values listed in Section 14 - Engine Specifications.

6. Assemble governor spring (A, Figure 22) to governor control lever (B).

NOTE: Governor spring must be installed in correct hole in governor control lever by engine model.

• Model 430400 - Top Hole

• Model 580400 - Bottom Hole

Figure 22

Initial Carburetor Adjustment

1. Turn idle mixture screw clockwise until it just seats. DO NOT FORCE. Turn screw counterclockwise 1/2 turn (Figure 23). This setting will permit engine to start.

NOTE: Final adjustment will be made with engine running.

Final Carburetor Adjustment

NOTICE: All carburetor adjustments must be made

with the air cleaner installed.

1. Start and run engine at low speed for approximately five minutes. Or, if equipped with a temperature gauge, until needle moves from C or COLD position.

2. With control lever on equipment in SLOW position, hold throttle lever (A, Figure 24) against idle speed screw and adjust idle speed to 1200 RPM.

Figure 24

3. SLOWLY turn idle mixture screw clockwise until engine speed just starts to slow (lean mixture).

4. Then SLOWLY turn idle mixture screw counter-clockwise until engine speed just starts to slow (rich mixture).

5. Turn idle mixture screw (A, Figure 25) to mid point between rich and lean.

10

Figure 23

71

Figure 25

6. Hold throttle lever against idle speed screw and readjust idle speed to 1500 RPM, or equipment manufacturer’s specification.

NOTE: If carburetor is equipped with an idle mixture limiter cap, install at this time.

7. Position limiter cap (B) so that stop(s) on the limiter cap are at mid point between stop(s) on carburetor body and press into position.

10

Automatic Choke Carburetor

The automatic choke consists of a vacuum choke break and a thermostat. The Intake manifold vacuum activates the vacuum choke break which partially opens the choke plate, to prevent over choking while the engine is being started. A vacuum limiter, located in the vacuum line, regulates vacuum to the vacuum choke break.

The thermostat contains a Positive Temperature Coefficient heater (P.T.C.) and a bi-metal spring which opens the choke plate gradually as the engine is running. When the keyswitch is turned “ON,” the battery current activates the P.T.C. heater which heats the bi-metal spring.

The P.T.C. Heater is a heat sensitive semiconductor porcelain. As the P.T.C. heater temperature rises, resistance increases, which regulates battery current to the heater and maintains the proper temperature for the bi-metal spring.

72

Automatic Choke Carburetor

Remove Carburetor

1. Disconnect fuel line and remove air cleaner tube from carburetor air horn. Disconnect vacuum line (A, Figure 26) from vacuum choke break. Disconnect wires from fuel shut off solenoid and automatic choke.

2. Unhook governor link spring (B) from throttle lever and disconnect governor link (C).

Disassemble Carburetor

1. Remove fuel shut off solenoid (A, Figure 28) and gasket (B). Remove float bowl (C) and bowl shim gasket (D).

10

Figure 28

NOTE: The float hinge pin (A, Figure 29) is swaged in one side. When removing, drive hinge pin from side opposite swage.

Figure 26

3. Remove two nuts and ground wire (A, Figure 27) from solenoid, air horn (B), carburetor (C), and insulator (D). Discard gaskets.

Figure 27

2. Drive out float hinge pin with a small punch. Remove float and fuel inlet valve (B).

3. Remove idle passage plug (C).

Figure 29

4. Remove rubber float bowl gasket (A, Figure 30).

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10

7. Remove screw and choke pre-load lever (A, Figure 33).

Figure 30

5. Remove fixed main jet (A, Figure 31) and gasket (B). Discard gasket.

Figure 33

8. Remove two screws, choke plate (B) and choke shaft (C).

9. Remove two screws and vacuum choke break (A, Figure 34).

Figure 31

6. Remove three screws, thermostat retainer (A, Figure 32) and ground wire (B). Discard thermostat gasket (C).

Figure 32

Figure 34

10. Remove idle jet plug (A, Figure 35) and idle jet (B).

74

Figure 37

10

Figure 35

11. Remove idle mixture screw (A, Figure 36) and o-ring (B). Discard o-ring.

Figure 36

NOTE: If engine is equipped with an electronic governor system, DO NOT remove throttle plate or throttle shaft. This is a precision assembly and should not be disassembled.

Clean Carburetor

Remove gasket material from mounting surfaces. Gummy or dirty carburetors should be cleaned in a carburetor cleaner. DO NOT soak rubber, neoprene, or plastic parts in cleaner.

NOTICE: If engine is equipped with an electronic governor system, DO NOT clean carburetor in carburetor cleaner. The carburetor is equipped with sealed ball bearings for the throttle shaft, which will be damaged if the carburetor is immersed in carburetor cleaner. Ball bearings are not replaceable.

Inspect Carburetor

Inspect all parts for wear, cracks, nicks, and burrs. Inspect float for leaks. Replace all damaged parts.

If engine is not equipped with an electronic governor, proceed to Step 12.

12. Mark throttle plate (A, Figure 37) before removing so that is may be reinstalled in the same position. The sides of the throttle plate are beveled.

13. Remove two screws, throttle plate, throttle shaft (B), and seal (C). Discard seal.

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10

Inspect Throttle, Choke Shaft, and Body

1. Lay carburetor on flat surface and check throttle and choke shaft clearance (Figure

38).

NOTE: Throttle shaft and choke shaft clearance must not exceed 0.010 in. (0.25 mm).

Figure 40

2. Install idle mixture screw (A, Figure 41) with new o-ring (B).

NOTE: Do not tighten idle mixture screw.

Figure 38

2. Inspect throttle shaft and choke shaft for wear (Figure 39).

Figure 41

3. Install idle jet (A, Figure 42) and plug (B).

Figure 39

• Replace if worn.

• If carburetor body is worn, replace carburetor.

Assemble Carburetor

When assembling the carburetor, use new seals and gaskets.

1. Install throttle shaft (A, Figure 40) and new seal (B). Install throttle plate and screws (C).

76

Figure 42

4. Assemble vacuum choke break (A, Figure 43) to bracket. Note correct position of pivot arm (B).

Figure 43

10

Figure 45

10. Hold choke plate closed and rotate thermostat until match marks are aligned (Figure 46). Tighten screws.

5. Install choke shaft through pivot arm bushing and into carburetor body (Figure 44).

NOTE: Specification between arms: 0.094 in. (2.5 mm).

Figure 44

6. Install choke plate.

7. Install thermostat with new gasket (A, Figure 45).

8. Insert hook (B) on thermostat spring between arms on choke shaft.

9. Assemble thermostat retainer leaving screws loose.

NOTE: Make sure choke plate remains closed while pre-loading thermostat spring.

Figure 46

11. Assemble choke pre-load lever (A, Figure

47) to choke shaft.

77

Figure 47

10

12. Install float. Assemble inlet valve to float (A, Figure 48).

13. Install float hinge pin (B), idle passage plug (C), fixed main jet with new gasket (D), and new bowl gasket (E).

Figure 48

14. Install float bowl with new gaskets (Figure

49).

Figure 50

1. Connect vacuum pump to choke break and activate pump to specification shown.

• Specification - 4.0 -5.5 in. Hg. vac. (10.0-

14.0 cm. Hg. vac.).

Choke plate should partially open and pump gauge should maintain vacuum.

2. Check dimension from edge of choke plate to edge of carburetor throat (Figure 51).

Figure 49

Check Vacuum Choke Break

A Mityvac® vacuum pump or equivalent is required when checking and adjusting the vacuum choke break.

78

Figure 51

• Specification - 0.550-.590 in. (14.0-15.0 mm).

If dimension is not to specification, the choke preload lever must be adjusted.

Adjust Choke Pre-Load Lever

1. Release vacuum pump so that the choke closes.

2. Manually open choke to end of travel and hold in this position.

3. Carefully bend pre-load lever (A, Figure 52).

• Bend lever to left in increase dimension (B).

• Bend lever to right to decrease dimension (C).

4. Recheck and adjust as necessary.

Figure 52

Check P.T.C. Heater

The Digital Multimeter # 19464 is required to test the P.T.C. heater.

1. Set the multimeter to the Ω position.

2. Check resistance between tab terminal on thermostat and ground wire as shown (Figure

53).

• Specification - 2.0-4.0 Ω @ (70° F)

3. Replace thermostat if not to specification.

Install Carburetor

1. Assemble insulator with gaskets, carburetor and air horn to intake manifold.

NOTE: Attach thermostat ground wire (A, Figure

54) to air horn.

10

Figure 54

2. Torque nuts to specifications shown in Section 14 - Engine Specifications.

3. Install governor link and governor link spring.

4. Reinstall air cleaner tube, vacuum line, harness connectors, and fuel line.

Figure 53

Install Vacuum Limiter

To install a vacuum limiter on engines not originally equipped with one, proceed as follows:

1. Cut vacuum line approximately 2.0 in. (50 mm) from vacuum break side and install vacuum limiter with blue end facing intake manifold (Figure 55).

Figure 55

79

10

Initial Carburetor Adjustment

1. Turn idle mixture screw clockwise until it just seats. DO NOT FORCE. Turn screw counterclockwise 1/2 turn (Figure 56). This setting will permit engine to start.

NOTE: Final adjustment will be made with engine running.

Figure 56

3. SLOWLY turn idle mixture screw clockwise until engine speed just starts to slow (lean mixture).

4. Then SLOWLY turn idle mixture screw counter-clockwise until engine speed just starts to slow (rich mixture).

5. Turn idle mixture screw to mid point between rich and lean (Figure 58).

Figure 58

Final Carburetor Adjustment

NOTICE: All carburetor adjustments must be made

with the air cleaner installed.

1. Start and run engine at low speed for approximately five minutes. Or, if equipped with a temperature gauge, until needle moves from C or COLD position.

2. With control lever on equipment in SLOW position, hold throttle lever (A, Figure 57) against idle speed screw and adjust idle speed to 1200 RPM.

6. Hold throttle lever against idle speed screw and readjust idle speed to 1500 RPM, or equipment manufacturer’s specification.

NOTE: If carburetor is equipped with an idle mixture limiter cap, install at this time.

7. Position limiter cap so that stop(s) on the limiter cap are at mid point between stop(s) on carburetor body and press into position.

Figure 57

80

Electric Fuel Pump

NEW STYLE PUMP

OLD STYLE PUMP

10

81

10

Check Fuel Pump Output

NOTE: A graduated container is required when

testing the fuel pump.

1. Disconnect fuel line at carburetor.

2. Turn ignition switch to ON position and note fuel flow into graduated container.

Figure 60

Test Fuel Pump Wiring

1. With keyswitch in OFF position, disconnect fuel pump equipment wiring harness connector.

2. Insert meter test leads into wiring harness connector (Figure 61).

Figure 59

3. If fuel flow is less than specification, replace fuel pump.

NOTE: A plugged fuel filter and/or low battery voltage may cause insufficient fuel flow.

4. If there is no fuel flow when keyswitch is in ON position, check fuel pump wiring.

Test Equipment

The Digital Multimeter #19464 is required to test the fuel pump.

The fuel pump test will be performed with the meter in the V== (DC Volts) position (Figure 60).

Figure 61

3. Turn the keyswitch to the ON position.

4. Meter should display battery voltage at connector.

5. If meter does not display battery voltage, problem is with wiring harness and/or fuel pump relay (as supplied by equipment manufacturer), and/or ignition module. Check for loose or broken wires.

82

Anti-Afterfire Solenoid

Some carburetors are equipped with an antiafterfire solenoid controlled by the equipment ignition switch. When the equipment switch is in the OFF position, the solenoid valve plunger closes, stopping fuel flow through the fixed main jet or high speed nozzle. When the switch is in the ON and START position, the solenoid valve opens, allowing normal fuel flow. The solenoid is operating properly if a click is heard when equipment ignition switch is turned ON and OFF. If solenoid is not working (defective solenoid or equipment wiring), the engine will not start or run.

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NOTE: Anti-afterfire solenoid requires a minimum of 9 volts DC to function.

NOTICE: Engines equipped with an anti-afterfire solenoid are equipped with an air horn gasket with a ground clip imbedded in the gasket (A, Figure 62). An Anti-afterfire solenoid will not function if ground clip is removed or damaged.

Figure 62

Figure 63

2. With keyswitch in OFF position, disconnect equipment wiring harness connector from solenoid.

3. Insert red meter test lead into wiring harness connector and attach black test lead to ground (Figure 64).

Figure 64

Test Anti-Afterfire Solenoid

If solenoid does not click, the problem may be in the equipment wiring. To determine whether the problem is with wiring, perform this test.

1. Set multimeter to the V== (DC volts) position (Figure 63).

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4. Turn keyswitch to ON position.

5. Meter should display battery voltage at connector. Test solenoid.

6. If meter does not display battery voltage, problem is with wiring harness, Check for loose or broken wires.

Test Solenoid

1. Remove solenoid from carburetor.

2. Place either terminal of a 9 volt transistor battery on the solenoid connector and other terminal on body of solenoid or ground wire (Figure 65).

3. Plunger should retract freely.

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4. When battery is removed, plunger should return freely.

5. Replace solenoid if plunger sticks or doesn’t move.

Figure 65

Fuel Filter

Carburetor Main Jets

The carburetor main jet orifice size is stamped in the body of the jet (Figure 67).

Figure 67

Figure 66

• Replace in-line fuel filter every 600 hours.

• In-line fuel filter has an arrow to indicate fuel flow direction, Always install arrow towards carburetor.

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ELECTRONIC FUEL INJECTION (EFI) SYSTEM

WARNING

The EFI fuel system remains under high pressure, even when the engine has stopped. Failure to release pressure before servicing could result in fire or explosion.

• Before attempting to service any part of the fuel system, the pressure must be relieved.

• Remove the spark plug.

• Disconnect negative battery cable.

• Ensure the engine is cold.

EFI Components

The system includes the following components:

• Air Temperature Sensor

• Crankshaft Position Sensor

• Crankshaft Reluctor Wheel

• Engine Control Unit (ECU)

• Engine Coolant Temperature Sensor

• Fuel Pump

• Fuel Filter

• Fuel Rail

• Fuel Injectors

• Heated Oxygen Sensor

• Ignition Coils

• Malfunction Indicator Light (MIL)

• Manifold Absolute Pressure (MAP) Sensor

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The EFI system controls two aspects of engine operation:

• The amount of fuel delivered to the engine

• The amount of ignition timing advance

The end result is optimum engine performance and maximum fuel economy while maintaining exhaust emission standards.

The Kiehn EFI system is equipped with an engine control unit (ECU) with a self-diagnostic function. If a malfunction in the system occurs, the ECU will identify the source and store the corresponding fault code(s).

A malfunction indicator lamp (MIL) will illuminate, indicating that the system needs service. The MIL will remain illuminated until the fault code(s) are read and the memory is reset.

The EFI system also employs a fail-safe function (limp home mode). If a major system malfunction were to occur, the engine would continue running at reduced capacity, based on parameters within the ECU, to prevent damage and avoid leaving the operator stranded.

Air Temperature Sensor

The air temperature sensor (Figure 1) provides continuous updates to the ECU on the air temperature entering the intake manifold. The ECU makes small corrections, based on certain temperature ranges, to increase or decrease the amount of fuel injected above the base injection time.

Figure 1

NOTICE: If an abnormal crankshaft pulse is detected, the ECU will shut the engine down to prevent damage from occurring.

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Crankshaft Position Sensor

The crankshaft position sensor (Figure 2) provides the ECU the signals needed to calculate RPM. This sensor controls the timing for the system to inject fuel as each intake valve opens, and controls when to apply voltage to the spark plug for the proper ignition-timing advance.

Engine Control Unit (ECU)

The Engine Control Unit (ECU) (Figure 4) collects information from the intake manifold pressure sensor, engine RPMs and various other sensors to determine the amount of compensation needed to the base injection time.

The ECU ensures the proper amount of fuel and ignition timing advance is delivered under various engine loads and RPMs. The fuel injection time is synchronized to the intake valve opening sequence.

Figure 2

Crankshaft Reluctor Wheel

The reluctor wheel (Figure 3) is attached to the back of the crankshaft accessory drive pulley. This wheel works with the Crankshaft Position Sensor to provide a momentary interruption in the magnetic field, producing the voltage spike used by the ECU to determine RPM. The large gap in the reluctor wheel identifies top dead center on the number 1 cylinder. The ECU sequences through the firing order until the last injector has been opened.

Figure 4

Engine Coolant Temperature Sensor

The coolant temperature sensor (Figure 5) provides the engine’s current operating temperature to the ECU. Under cold start conditions, the ECU makes corrections to the base injection time to keep the injectors open longer, delivering more fuel during warm up.

Figure 3

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Figure 5

Fuel Pump

An electric fuel pump (Figure 6) transfers fuel in the EFI system. Depending on the application, the pump may be inside the fuel tank, or in the fuel line near the tank. Through a relay, the ECU activates the fuel pump to pressurize the system. The fuel pump remains on while the engine is running.

Figure 6

Fuel Rail

The fuel rail (Figure 8) is a formed tube assembly that feeds fuel to the top of the injectors. A valve in the rail allows for testing the operating pressure or relieving fuel system pressure when servicing. When the rail is assembled to the manifold, formed cups in the rail lock the injectors into place. A small retaining clip provides a secondary lock.

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Figure 8

Fuel Filter

EFI engines use a high volume, high-pressure, inline fuel filter (Figure 7).

Figure 7

Fuel Injectors

The fuel injector (Figure 9) is an electromagnetic device that opens when voltage is delivered from the ECU. The longer the voltage is applied, the longer the injector will stay open. The injector sprays a fine mist of highly atomized fuel at the back of the intake valve through the intake port.

Figure 9

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Heated Oxygen Sensor

The oxygen sensor (Figure 10) is the last in-line device to the ECU, providing information about the effectiveness of the ECU’s output commands. The oxygen sensor is placed in the exhaust system to detect whether the engine is operating in a rich or lean state.

The sensor creates an electrical signal when it senses a difference in the level of oxygen in the exhaust compared to the outside atmosphere.

An integral heating element brings the sensor up to operating temperature quickly.

Figure 10

Ignition Coil

The ECU triggers the ignition coil (Figure 11) to fire, sending voltage to each spark plug when needed.

Malfunction Indicator Light (MIL)

If the self-diagnostic feature detects a fault, the fault code is displayed on the malfunction indicator lamp (MIL) (Figure 12) and is recorded in the ECU. The fault is stored until the memory is reset.

Figure 12

Manifold Absolute Pressure (MAP) Sensor

The manifold absolute pressure (MAP) sensor (Figure 13) measures the amount of vacuum in the intake manifold. This sensor uses a constant absolute pressure to eliminate the effects of changing atmospheric conditions.

The sensor uses a 5 volt input reference and, as pressure changes, it increases or decreases the amount of voltage returned to the ECU, which mathematically determines the engine load and regulates the amount of fuel to be injected.

Figure 11

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Figure 13

Troubleshooting

When troubleshooting an engine with EFI, basic engine operating problems must be addressed before turning to the EFI system components.

Engine starts hard or fails to start when cold

1. Fuel pump inoperative

2. Engine temperature sensor inoperative

3. Insufficient fuel pressure

4. Crankshaft position sensor inoperative

5. Crankshaft position sensor offset incorrect

6. Old/stale fuel

7. Low system voltage

8. Injectors clogged or restricted

9. Coils inoperative

10. Spark plugs fouled, worn, or damaged

Engine starts hard or fails to start when hot

1. Fuel pressure low

2. Fuel pump inoperative

3. Insufficient fuel pressure

4. Crankshaft position sensor inoperative

5. Crankshaft position sensor offset incorrect

6. Injectors clogged or restricted

7. Spark plugs fouled, worn, or damaged

Electrical System

The EFI system is 12VDC with negative ground. A fully-charged 12 volt battery with a minimum of 350 cold cranking amps is required to maintain reliable system operation. Battery condition and state of charge should always be checked first when troubleshooting the EFI system.

EFI-related problems are more likely caused by the wiring harness or connections than by the EFI components. Even small amounts of corrosion or oxidation on the terminals can interfere with the milliamp currents used in system operation. Cleaning the connectors and grounds will solve problems in many cases.

If a fault code indicates a problem with an EFI component, disconnect the ECU connector and test for continuity between the component connector terminals and the corresponding terminals in the ECU connector.

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Engine misses, hesitates, or stalls under load

1. Fuel injectors/fuel filter/fuel line dirty or restricted

2. Air cleaner dirty

3. Fuel pressure or fuel volume insufficient

4. Vacuum (intake air) leak

5. Governor setting incorrect

6. Spark plugs fouled, worn or incorrect gap

7. Plug wires loose or worn

Low Power

1. Air cleaner dirty

2. Fuel pressure insufficient

3. Governor setting incorrect

4. Exhaust system plugged or restricted

5. Injector(s) dirty or clogged

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FAULT CODES

10

FAULT CODE

02 Crankshaft Position Sensor

09 Intake Manifold Pressure

12 Water Temperature Sensor

13 Intake Air Temperature

17 Oxygen Sensor

24 Battery Voltage

27 VCC Circuit

33 Fuel Injector #1

COMPONENT MIL Flashes

Sensor

Long Flash Short Flash

34 Fuel Injector #2

35 Fuel Injector #3

37 Ignition Coil #1

38 Ignition Coil #2

39 Ignition Coil #3

41 Fuel Pump Relay

45 Heated Oxygen Sensor

58 Water Temperature

Warning Lamp

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Fault Code on MIL Indicator

The MIL will display sequences of flashes that indicate a fault within the EFI system.

The number of flashes represents the number of the code.

For example, if there was an issue with battery voltage, the fault code 24 would be displayed on the MIL.This is represented by two long flashes followed by four short flashes, as shown below.

If more than one fault condition has occurred, a twosecond pause will occur between each of the code flashes.

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