Kohler 1500, TP-2509, LV560, 05810334 User Manual

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SERVICE MANUAL

KOHLER® AEGIS

LIQUID-COOLED VERTICAL CRANKSHAFT

™

17,20,23 HP

Contents

Section 1. Safety and General Information ............................................................................

Section 2. Special Tools ..........................................................................................................

Section 3. Troubleshooting .....................................................................................................

Section 4. Air Cleaner and Air Intake System ........................................................................

Section 5. Fuel System and Governor....................................................................................

Section 6. Lubrication System ................................................................................................

Section 7. Cooling System ......................................................................................................

Section 8. Electrical System and Components .....................................................................

Section 9. Disassembly ...........................................................................................................

Section 10. Inspection and Reconditioning ...........................................................................

Section 11. Reassembly...........................................................................................................

Safety and General Information

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LV560, LV625, LV675

Section 1

Safety and General Information

Safety Precautions

To insure safe operations please read the following statements and understand their meaning. Also refer to your equipment manufacturer's manual for other important safety information. This manual contains safety precautions which are explained below . Please read carefully.

WARNING

Warning is used to indicate the presence of a hazard that can cause severe personal injury, death, or substantial property damage if the warning is ignored.

CAUTION

Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the caution is ignored.

Section 1

NOTE

Note is used to notify people of installation, operation, or maintenance information that is important but not hazard-related.

For Y our Safety!

These precautions should be followed at all times. Failure to follow these precautions could result in injury to yourself and others.

WARNING

Accidental Starts can cause severe injury or death.

Disconnect and ground spark plug leads before servicing.

Accidental St arts!

Disabling engine. Accidental starting can cause severe injury or death. Before working on the

engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-) battery cable from battery .

WARNING

Rotating Parts can cause severe injury.

Stay away while engine is in operation.

Rotating Part s!

Keep hands, feet, hair, and clothing away from all moving parts to prevent injury. Never operate the engine with covers, shrouds, or guards removed.

Hot Parts can cause severe burns.

Do not touch engine while operating or just after stopping.

Hot Parts!

Engine components can get extremely hot from operation. To prevent severe burns, do not touch these areas while the engine is running - or immediately after it is turned off. Never operate the engine with heat shields or guards removed.

WARNING

1.1

Section 1 Safety and General Information

WARNING

Explosive Fuel can cause fires and severe burns.

Stop engine before filling fuel tank.

Explosive Fuel!

Gasoline is extremely flammable and its vapors can explode if ignited. Store gasoline only in approved containers, in well ventilated, unoccupied buildings, away from sparks or flames. Do not fill the fuel tank while the engine is hot or running, since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition. Do not start the engine near spilled fuel. Never use gasoline as a cleaning agent.

WARNING

WARNING WARNING

Carbon Monoxide can cause severe nausea, fainting or death.

Do not operate engine in closed or confined area.

Lethal Exhaust Gases!

Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled. Avoid inhaling exhaust fumes, and never run the engine in a closed building or confined area.

WARNING

Hot liquid can cause severe burns.

Do not loosen radiator cap while engine is operating or warm to the touch.

Explosive Gas can cause fires and severe acid burns.

Charge battery only in a well ventilated area. Keep sources of ignition away.

Explosive Gas!

Batteries produce explosive hydrogen gas while being charged. To prevent a fire or explosion, charge batteries only in well ventilated areas. Keep sparks, open flames, and other sources of ignition away from the battery at all times. Keep batteries out of the reach of children. Remove all jewelry when servicing batteries.

Before disconnecting the negative (-) ground cable, make sure all switches are OFF. If ON, a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present.

Cleaning Solvents can cause severe injury or death.

Use only in well ventilated areas away from ignition sources.

Flammable Solvents!

Carburetor cleaners and solvents are extremely flammable. Keep sparks, flames, and other sources of ignition away from the area. Follow the cleaner manufacturer’s warnings and instructions on its proper and safe use. Never use gasoline as a cleaning agent.

1.2

Hot Liquid!

The liquid coolant can get extremely hot from operation. T urning the radiator cap when the engine is hot can allow steam and scalding liquid to blow out and burn you severely .

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

CAUTION

Electrical Shock can cause injury.

Do not touch wires while engine is running.

Electrical Shock!

Never touch electrical wires or components while the engine is running. They can be sources of electrical shock.

Engine Identification Numbers

When ordering parts, or in any communication involving an engine, always give the Model, Specification and Serial Numbers, including letter suffixes if there are any.

The engine identification numbers appear on a decal, or decals, affixed to the engine shrouding. See Figure 1-1. An explanation of these numbers is shown in Figure 1-2.

Section 1

Safety and General Information

Figure 1-1. Engine Identification Decal Location.

A. Model No.

Liquid Cooled Vertical Crankshaf t Displacement/Size (cc)

B. Spec. No.

Engine Model Code Code Model

81 LV560 83 LV625 85 LV675

C. Serial No.

Year Manufactured Code

Code Year

30 2000 31 2001

Figure 1-2. Explanation of Engine Identification Numbers.

L V 675 S

Version Code

S = Electric Start

85 1500

Variation of Basic Engine

30 05810334

Factory Code

1.3

Section 1 Safety and General Information

Oil Recommendations

Using the proper type and weight of oil in the crankcase is extremely important. So is checking oil daily and changing oil regularly . Failure to use the correct oil, or using dirty oil, causes premature engine wear and failure.

Oil T ype Use high-quality detergent oil of API (American Petroleum Institute) Service Class SG, SH, SJ or higher. Select the viscosity based on the air

temperature at the time of operation as shown in the following table.

*Use of synthetic oil having 5W-20 or 5W-30 rating is

acceptable, up to 4°C (40°F). **Synthetic oils will provide better starting in extreme cold below -23°C (-10°F).

NOTE: Using other than service class SG, SH, SJ or

higher oil or extending oil change intervals longer than recommended can cause engine damage.

Refer to Section 6 - “Lubrication System” for detailed procedures on checking the oil, changing the oil and changing the oil filter.

Coolant Recommendations

Use equal parts of ethylene glycol and water only. Distilled or deionized water is recommended, especially in areas where the water contains a high mineral content. Propylene glycol based anti-freeze is not recommended.

This mixture will provide protection from -37º C (-34º F) to 108º C (226º F). For protection and use outside the indicated temperature limits, follow the anti-freeze manufacturer's instructions on the container , but do not exceed 70% anti-freeze.

DO NOT use anti-freeze with stop-leak additive(s), or put any other additives in the cooling system.

Fuel Recommendations

WARNING: Explosive Fuel!

A logo or symbol on oil cont ainers identifies the API service class and SAE viscosity grade. See Figure 1-3.

Figure 1-3. Oil Container Logo.

1.4

General Recommendations

Purchase gasoline in small quantities and store in clean, approved containers. A cont ainer with a capacity of 2 gallons or less with a pouring spout is recommended. Such a container is easier to handle and helps eliminate spillage during refueling.

Do not use gasoline left over from the previous season, to minimize gum deposits in your fuel system and to ensure easy starting.

Do not add oil to the gasoline.

Do not overfill the fuel tank. Leave room for the fuel to expand.

Section 1

Safety and General Information

Fuel Type

For best results, use only clean, fresh, unleaded gasoline with a pump sticker octane rating of 87 or higher. In countries using the Research method, it should be 90 octane minimum.

Unleaded gasoline is recommended, as it leaves fewer combustion chamber deposits. Leaded gasoline may be used in areas where unleaded is not available and exhaust emissions are not regulated. Be aware, however, that the cylinder head will require more frequent service.

Gasoline/Alcohol blends

Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) is approved as a fuel for Kohler engines. Other gasoline/alcohol blends are not approved.

Gasoline/Ether blends

Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved as a fuel for Kohler engines. Other gasoline/ether blends are not approved.

Periodic Maintenance

WARNING: Accident al Starts!

Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-) battery cable from battery .

Maintenance Schedule

These required maintenance procedures should be performed at the frequency stated in the table. They should also be included as part of any seasonal tune-up.

Refer to:

Section 5 Section 6 Section 7 Section 4 Section 4

Section 4 Section 4

Section 7 Section 5

Section 6 Section 8

Section 8 Section 8

Daily or Before

Starting Engine

Every 25 Hours

Every 100 Hours

Annually or

Every 200 Hours

Annually or

Every 500 Hours

Maintenance RequiredFrequency

• Fill fuel tank.

• Check oil level.

• Check coolant level.

• Check air cleaner for dirty1, loose, or damaged parts.

• Check air intake screen, radiator , and cooling areas, clean as necessary1.

• Service precleaner element1.

• Replace air cleaner element1.

• Clean and check cooling areas.

• Replace fuel filter.

• Change oil and oil filter (more frequently under severe conditions).

• Check spark plug condition and gap.

• Have solenoid shift starter disassembled and cleaned2.

• Replace spark plugs.

Every 2 Y ears or

Every 1000 Hours

Perform these maintenance procedures more frequently under extremely dusty, dirty conditions.

Only required for Denso starters. Not necessary on Delco starters. Have a Kohler Engine Service Dealer perform

this service.

• Change engine coolant.

Section 7

1.5

Section 1 Safety and General Information

Storage

If the engine will be out of service for two months or more, use the following storage procedure:

1. Clean the exterior surfaces of the radiator and engine.

2. Change the oil and filter while the engine is still warm from operation. See “Change Oil and Filter” in Section 6.

3. The coolant (anti-freeze) mixture should be in good condition and tested to guard against freezing in cold temperatures. The recommended equal parts mixture will normally provide protection down to temperatures of -37° C (-34° F). If storage temperatures will fall below this, the cooling system should be drained. A note should then be attached to the equipment and/or engine as a reminder to refill the cooling system before starting.

4. The fuel system must be completely emptied, or the gasoline must be treated with a stabilizer to prevent deterioration. If you choose to use a stabilizer , follow the manufacturer’s recommendations, and add the correct amount for the capacity of the fuel system. Fill the fuel tank with clean, fresh gasoline. Run the engine for 2-3 minutes to get stabilized fuel into the carburetor. Close fuel shut-of f valve when unit is being stored or transported.

To empty the system, run the engine until the tank and system are empty .

5. Remove the spark plugs. Add one tablespoon of engine oil into each spark plug hole. Install plugs, but do not connect the plug leads. Crank the engine two or three revolutions.

6. Store the engine in a clean, dry place.

1.6

479.3

Over All

434.1

Cyl. #2

Fuel Pump

Hose

260.6

Cyl. #1

Section 1

Safety and General Information

334.5

167.2

89.8 2x

72.8

Coolant Drain Plug 3/8 N.P.T Inch

Oil Fill & Dipstick

430.6

Mounting Hole ‘‘A’’

40.8

Oil Drain

140.0

135.7

Mounting Hole ‘‘A’’

285.5 Oil Fill

451.0

Oil Drain Plug 3/8 N.P.T inch

Mounting

Surface

73.5

Exhaust

Port #2

93.5

Exhaust Port #1

153.0 Housing Removal

155.5

Spark

Plug

18.2

472.4

Oil Fill &

Dipstick

Oil Fill

50.0 Exhaust Port #1

Starter Motor

4x ø 9.2 (.36) thru

254.0 (10.00) B.C

Fuel Pump

118.3

30º

50.0 Exhaust Port #2

104.0

15.7 Oil Filter Removal

Mounting Hole ‘‘A’’ø 135.0

Oil Filter

13.2

26.8 Oil Drain

Oil Drain Plug 3/8 N.P.T Inch

Mounting Hole ‘‘A’’

89.8

51.2

242.2

Spark Plug

Mounting Surface

135.5

30º

35º

45º

Oil Filter

95.5

86.3 Oil

ø 28.6

Filter

139.8

Center of Gravity

Mounting Hole ‘‘A’’

95.8

Center of Gravity

Figure 1-4. T ypical Engine Dimensions.

Center of

Mounting Surface

199.0

Gravity

Dimensions in millimeters.

1.7

Section 1 Safety and General Information

General Specifications

Power (@ 3600 RPM, corrected to SAE J1995)

LV560............................................................................................. 12.7 kW (17 HP)

LV625............................................................................................. 14.9 kW (20 HP)

LV675............................................................................................. 17.1 kW (23 HP)

Peak Torque

L V560 (@ 2400 RPM).................................................................... 32.5 N·m (24 ft. lb.)

L V625 (@ 2400 RPM).................................................................... 41 N·m (30 ft. lb.)

L V675 (@ 2400 RPM).................................................................... 44 N·m (32 ft. lb.)

Bore LV560.......................................................................................... 73 mm (2.87 in.)

LV625.......................................................................................... 77 mm (3.03 in.)

LV675.......................................................................................... 80 mm (3.14 in.)

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

Displacement

LV560............................................................................................. 561 cc (34.2 cu. in.)

LV625............................................................................................. 624 cc (38.1 cu. in.)

LV675............................................................................................. 674 cc (41.1 cu. in.)

Compression Ratio ............................................................................. 8.2:1 (LV560)

8.5:1 (L V625, LV675)

Dry Weight .......................................................................................... 49.8 kg (110 lb.)

Oil Capacity (with filter)......................................................................... 1.9 L (2.0 U.S. qt.)

Coolant Capacity (equal parts of water and ethylene glycol)................. 1.4 L (1.5 U.S. qt.)

Angle of Operation - Maximum (at full oil level) All Directions............... 20°

Lower Blower Housing

M5 Fasteners Torque............................................................................ 4.0 N·m (35 in. lb.)

M6 Fasteners Torque............................................................................ 6.8 N·m (60 in. lb.)

Rectifier Fastener Torque ..................................................................... 4.0 N·m (35 in. lb.)

Camshaft

End Play (With Shim) ........................................................................... 0.076/0.127 mm (0.0030/0.0050 in.)

Running Clearance............................................................................... 0.025/0.063 mm (0.0010/0.0025 in.)

Bore I.D.

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

Max. Wear Limit............................................................................. 20.038 mm (0.7889 in.)

Camshaft Bearing Surface O.D.

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

Max. Wear Limit............................................................................. 19.959 mm (0.7858 in.)

V alues are in Metric units. Values in parentheses are English equivalents. Lubricate threads with engine oil prior

to assembly .

1.8

Section 1

Safety and General Information

Carburetor and Intake Manifold

Intake Manifold Mounting Fasteners Torque ......................................... 6.2 N·m (55 in. lb.)

Carburetor Mounting Fasteners Torque ................................................ 6.2 N·m (55 in. lb.)

Connecting Rod

Cap Fastener Torque (torque in increments) ........................................ 11.3 N·m (100 in. lb.)

Connecting Rod-to-Crankpin Running Clearance

New................................................................................................ 0.043/0.068 mm (0.0016/0.0026 in.)

Max. Wear Limit............................................................................. 0.083 mm (0.0032 in.)

Connecting Rod-to-Crankpin Side Clearance ....................................... 0.26/0.63 mm (0.0102/0.0248 in.)

Connecting Rod-to-Piston Pin Running Clearance ............................... 0.015/0.028 mm (0.0006/0.001 1 in.)

Piston Pin End I.D.

New................................................................................................ 17.015/17.023 mm (0.6699/0.6702 in.)

Max. Wear Limit............................................................................. 17.036 mm (0.6707 in.)

Crankcase

Governor Cross Shaft Bore I.D.

New................................................................................................ 8.025/8.075 mm (0.3159/0.3179 in.)

Max. Wear Limit............................................................................. 8.088 mm (0.3184 in.)

Breather Cover Fasteners Torque......................................................... 10.7 N·m (95 in. lb.) Into new as-cast hole

7.3 N·m (65 in. lb.) Into used hole

Oil Drain Plugs...................................................................................... 13.6 N·m (120 in. lb.)

Crankshaft

End Play (free)...................................................................................... 0.070/0.590 mm (0.0028/0.0232 in.)

Crankshaft Bore (in crankcase)

New................................................................................................ 40.974/40.987 mm (1.6131/1.6136 in.)

Max. Wear Limit............................................................................. 41.000 mm (1.6141 in.)

Crankshaft Bore (in oil pan)

New................................................................................................ 40.974/41.000 mm (1.6131/1.6141 in.)

Max. Wear Limit............................................................................. 41.038 mm (1.6156 in.)

Crankshaft Bore (in oil pan)-to-Crankshaft

Running Clearance - New .............................................................. 0.039/0.087 mm (0.0015/0.0034 in.)

Main Bearing Journals

O.D. - New ..................................................................................... 40.913/40.935 mm (1.6107/1.6116 in.)

O.D. - Max. Wear Limit .................................................................. 40.84 mm (1.608 in.)

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

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

Crankshaft Bore (in crankcase)-to-Crankshaft

Running Clearance - New .............................................................. 0.039/0.074 mm (0.0015/0.0029 in.)

1.9

Section 1 Safety and General Information

Crankshaft (Cont'd.)

Connecting Rod Journal

O.D. - New ..................................................................................... 35.955/35.973 mm (1.4156/1.4163 in.)

O.D. - Max. Wear Limit .................................................................. 35.94 mm (1.415 in.)

Max. Taper ..................................................................................... 0.018 mm (0.0007 in.)

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

Crankshaft T.I.R.

PTO End, Crank in Engine............................................................. 0.15 mm (0.0059 in.)

Entire Crank, in V-Blocks ............................................................... 0.10 mm (0.0039 in.)

Cylinder Bore

Cylinder Bore I.D.

New

LV560.......................................................................................... 73.006/73.031 mm (2.8742/2.8752 in.)

LV625.......................................................................................... 77.000/77.025 mm (3.0315/3.0325 in.)

LV675.......................................................................................... 80.000/80.025 mm (3.1496/3.1506 in.)

Max. Wear Limit

LV560.......................................................................................... 73.070 mm (2.8767 in.)

LV625.......................................................................................... 77.063 mm (3.0340 in.)

LV675.......................................................................................... 80.065 mm (3.1522 in.)

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

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

Cylinder Head

Cylinder Head Fastener Torque (torque in 2 increments)...................... 16.9, 33.9 N·m (150, 300 in. lb.)

Max. Out-of-Flatness............................................................................ 0.076 mm (0.003 in.)

Rocker Pivot Fastener Torque, if Screw................................................ 1 1.3 N·m (100 in. lb.)

Rocker Pivot Fastener Torque, if Nut .................................................... 15.8 N·m (140 in. lb.)

Electric Starter

St arter Mounting Fastener Torque ........................................................ 15.3 N·m (135 in. lb.)

Fan/Flywheel

Fan Fastener Torque ............................................................................ 13.6 N·m (120 in. lb.)

Flywheel Retaining Screw Torque ......................................................... 66.4 N·m (49 ft. lb.)

Governor

Governor Cross Shaft to Crankcase Running Clearance...................... 0.025/0.126 mm (0.0009/0.0049 in.)

Governor Cross Shaft O.D.

New................................................................................................ 7.949/8.000 mm (0.3129/0.3149 in.)

Max. Wear Limit............................................................................. 7.936 mm (0.3124 in.)

Governor Gear Shaft O.D.

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

Max. Wear Limit............................................................................. 5.977 mm (0.2353 in.)

Governor Gear Shaft-to-Governor Gear Running Clearance................ 0.090/0.160 mm (0.0035/0.0063 in.)

1.10

Section 1

Safety and General Information

Ignition

Sp ark Plug Type (Champion® or equivalent) ......................................... RC14YC (Kohler Part No. 66 132 01-S)

Sp ark Plug Gap .................................................................................... 0.76 mm (0.030 in.)

Sp ark Plug Torque ................................................................................ 24.4-29.8 N·m (18-22 ft. lb.)

Ignition Module Air Gap ........................................................................ 0.2/0.3 mm (0.008/0.012 in.)

Ignition Module Fastener Torque .......................................................... 6.2 N·m (55 in. lb.) Into new as-cast hole

3.9 N·m (35 in. lb.) Into used hole

Muffler

Muffler Retaining Nuts Torque .............................................................. 24.4 N·m (216 in. lb.)

Oil Filter/Oil Pan

Oil Filter Torque .................................................................................... 8.1-9.4 N·m (72-84 in. lb.)

Oil Pan Fastener Torque ....................................................................... 24.4 N·m (216 in. lb.)

Piston, Piston Rings, and Piston Pin

Piston-to-Piston Pin .............................................................................. 0.006/0.018 mm (0.0002/0.0007 in.)

Piston Pin Bore I.D.

New................................................................................................ 17.006/17.013 mm (0.6695/0.6698 in.)

Max. Wear Limit............................................................................. 17.025 mm (0.6703 in.)

Piston Pin O.D.

New................................................................................................ 16.995/17.000 mm (0.6691/0.6693 in.)

Max. Wear Limit............................................................................. 16.994 mm (0.6691 in.)

Top Compression Ring-to-Groove Side Clearance

LV560............................................................................................. 0.040/0.096 mm (0.0016/0.0037 in.)

LV625............................................................................................. 0.040/0.086 mm (0.0016/0.0034 in.)

LV675............................................................................................. 0.050/0.096 mm (0.0012/0.0030 in.)

Middle Compression Ring-to-Groove Side Clearance

LV560............................................................................................. 0.030/0.080 mm (0.0012/0.0031 in.)

LV625............................................................................................. 0.040/0.086 mm (0.0016/0.0034 in.)

LV675............................................................................................. 0.030/0.076 mm (0.0012/0.0030 in.)

Oil Control Ring-to-Groove Side Clearance

LV560............................................................................................. 0.046/0.201 mm (0.0018/0.0079 in.)

LV625............................................................................................. 0.046/0.196 mm (0.0018/0.0077 in.)

LV675............................................................................................. 0.046/0.196 mm (0.0018/0.0077 in.)

1.11

Section 1 Safety and General Information

Piston, Piston Rings, and Piston Pin (Cont'd.)

Top and Middle Compression Ring End Gap

LV560

New Bore

Top Ring .................................................................................. 0.180/0.380 mm (0.0071/0.0150 in.)

Middle Ring ............................................................................. 0.180/0.440 mm (0.0071/0.0173 in.)

Used Bore (Max.)........................................................................ 0.76 mm (0.029 in.)

LV625

New Bore

Top Ring .................................................................................. 0.180/0.380 mm (0.0071/0.0150 in.)

Middle Ring ............................................................................. 0.250/0.450 mm (0.0098/0.0177 in.)

Used Bore (Max.)........................................................................ 0.77 mm (0.030 in.)

LV675

New Bore

Top Ring .................................................................................. 0.180/0.430 mm (0.0071/0.0169 in.)

Middle Ring ............................................................................. 0.250/0.460 mm (0.0098/0.0181 in.)

Used Bore (Max.)........................................................................ 0.80 mm (0.0315 in.)

Piston Thrust Face O.D.²

LV560

New ............................................................................................ 72.966/72.984 mm (2.8727/2.8734 in.)

Max. Wear Limit.......................................................................... 72.839 mm (2.8677 in.)

LV625

New ............................................................................................ 76.967/76.985 mm (3.0302/3.0309 in.)

Max. Wear Limit.......................................................................... 76.840 mm (3.0252 in.)

LV675

New ............................................................................................ 79.963/79.981 mm (3.1481/3.1488 in.)

Max. Wear Limit.......................................................................... 79.831 mm (3.1430 in.)

Piston Thrust Face-to-Cylinder Bore² Running Clearance

LV560............................................................................................. 0.022/0.065 mm (0.0009/0.0026 in.)

LV625............................................................................................. 0.014/0.057 mm (0.0005/0.0022 in.)

LV675............................................................................................. 0.019/0.062 mm (0.0007/0.0024 in.)

Speed Control

Speed Control Bracket Assembly Fastener Torque............................... 10.7 N·m (95 in. lb.) Into new as-cast hole

7.3 N·m (65 in. lb.) Into used hole

Stator

St ator Mounting Screw Torque.............................................................. 6.2 N·m (55 in. lb.)

Throttle/Choke Controls

Governor Control Lever Fastener Torque ............................................. 9.9 N·m (88 in. lb.)

Valve Cover/Rocker Arms

V alve Cover Fastener Torque ............................................................... 6.2 N·m (55 in. lb.)

Valves and Valve Lifters

Hydraulic V alve Lifter to Crankcase Running Clearance....................... 0.0124/0.0501 mm (0.0004/0.0020 in.)

Intake V alve S tem-to-Valve Guide Running Clearance ......................... 0.038/0.076 mm (0.0015/0.0030 in.)

Exhaust V alve S tem-to-Valve Guide Running Clearance...................... 0.050/0.088 mm (0.0020/0.0035 in.)

²Measure 6 mm (0.236 in.) above the bottom of the piston skirt at right angles to the piston pin.

1.12

Safety and General Information

Valves and Valve Lifters (Cont'd.)

Intake V alve Guide I.D.

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

Max. Wear Limit............................................................................. 7.134 mm (0.2809 in.)

Intake V alve Stem Diameter

New................................................................................................ 6.982/7.000 mm (0.2749/0.2756 in.)

Exhaust V alve Guide I.D.

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

Max. Wear Limit............................................................................. 7.159 mm (0.2819 in.)

Exhaust V alve Stem Diameter

New................................................................................................ 6.970/6.988 (0.2744/0.2751 in.)

V alve Guide Reamer Size

St andard......................................................................................... 7.048 mm (0.2775 in.)

0.25 mm O.S.................................................................................. 7.298 mm (0.2873 in.)

Intake V alve Minimum Lift..................................................................... 8.88 mm (0.3496 in.)

Section 1

Exhaust V alve Minimum Lift.................................................................. 8.88 mm (0.3496 in.)

Nominal V alve Seat Angle..................................................................... 45°

General Torque Values

Metric Fastener T orque Recommendations for St andard Applications

Tightening Torque: N·m (in. lb.) + or - 20%

Property Class

Noncritical

4.8

Size M4 1.2 (1 1) 1.7 (15) 2.9 (26) 4.1 (36) 5.0 (44) 2.0 (18) M5 2.5 (22) 3.2 (28) 5.8 (51) 8.1 (72) 9.7 (86) 4.0 (35) M6 4.3 (38) 5.7 (50) 9.9 (88) 14.0 (124) 16.5 (146) 6.8 (60) M8 10.5 (93) 13.6 (120) 24.4 (216) 33.9 (300) 40.7 (360) 17.0 (150)

5.8

8.8

10.9

12.9

Fasteners

Into Aluminum

Tightening Torque: N·m (ft. lb.) + or -20%

Property Class

Noncritical

4.8

M10 21.7 (16) 27.1 (20) 47.5 (35) 66.4 (49) 81.4 (60) 33.9 (25) M12 36.6 (27) 47.5 (35) 82.7 (61) 1 16.6 (86) 139.7 (103) 61.0 (45) M14 58.3 (43) 76.4 (55) 131.5 (97) 184.4 (136) 219.7 (162) 94.9 (70)

5.8

8.8

10.9

12.9

Fasteners

Into Aluminum

1.13

Section 1 Safety and General Information

English Fastener Torque Recommendations for Standard Applications

Tightening Torque: N·m (in. lb.) + or - 20%

Bolts, Screws, Nuts and Fasteners Assembled Into Cast Iron or Steel

Grade 2 Grade 5 Grade 8

Size 8-32 2.3 (20) 2.8 (25) --------- 2.3 (20) 10-24 3.6 (32) 4.5 (40) --------- 3.6 (32) 10-32 3.6 (32) 4.5 (40) --------- --------- 1/4-20 7.9 (70) 13.0 (115) 18.7 (165) 7.9 (70) 1/4-28 9.6 (85) 15.8 (140) 22.6 (200) --------- 5/16-18 17.0 (150) 28.3 (250) 39.6 (350) 17.0 (150) 5/16-24 18.7 (165) 30.5 (270) --------- --------- 3/8-16 29.4 (260) --------- --------- --------- 3/8-24 33.9 (300) --------- --------- ---------

Grade 2 or 5 Fasteners Into Aluminum

Tightening Torque: N·m (ft. lb.) + or - 20%

Size 5/16-24 --------- ---------- 40.7 (30) --------3/8-16 --------- 47.5 (35) 67.8 (50) --------3/8-24 --------- 54.2 (40) 81.4 (60) --------7/16-14 47.5 (35) 74.6 (55) 108.5 (80) --------7/16-20 61.0 (45) 101.7 (75) 142.4 (105) --------1/2-13 67.8 (50) 108.5 (80) 155.9 (115) --------1/2-20 94.9 (70) 142.4 (105) 223.7 (165) --------9/16-12 101.7 (75) 169.5 (125) 237.3 (175) --------9/16-18 135.6 (100) 223.7 (165) 31 1.9 (230) --------5/8-11 149.2 (1 10) 244.1 (180) 352.6 (260) --------5/8-18 189.8 (140) 311.9 (230) 447.5 (330) --------3/4-10 199.3 (150) 332.2 (245) 474.6 (350) --------3/4-16 271.2 (200) 440.7 (325) 637.3 (470) ---------

1.14

Torque

Conversions

N·m = in. lb. x 0.1 13 N·m = ft. lb. x 1.356 in. lb. = N·m x 8.85 ft. lb. = N·m x 0.737

Section 2

Go Back

Section 2

LV560, LV625, LV675

Special Tools

These quality tools are designed to help you perform specific disassembly , rep air , and reassembly procedures. By using tools designed for the job, you can service engines easier, faster, and safer! In addition, you’ll increase your service capabilities and customer satisfaction by decreasing engine downtime.

Camshaft End play Plate ................................................................................. KO1031*

Flywheel Puller Kit ........................................................................................... NU3226*

Hose Clamp Pliers........................................................................................... KO1043*

V alve Guide Reamer........................................................................................ KO1026*

Hydraulic Lifter Removal Tool .......................................................................... KO1044*

Rocker Arm Spanner Wrench .......................................................................... (Obtain locally)

Water Manometer............................................................................................ 25 761 02-S

V acuum Gauge................................................................................................ 25 761 22-S

Cylinder Leakdown Tester................................................................................ 25 761 05-S

Ignition System Tester ..................................................................................... 24 455 02-S

St arter Ring Tool .............................................................................................. 25 761 18-S

*These items can be ordered through your Kohler distributor or purchased directly from SPX Corp. by phoning 1-800-533-0492.

Ignition System Tester

Use Kohler Part No. 24 455 02-S to test the CD ignition modules on the AEGIS™ engines.

Cylinder Leakdown Tester

Kohler Part No. 25 761 05-S Cylinder Leakdown Tester is a valuable alternative to a compression test. By pressurizing the combustion chamber from an external air source, this tool can determine if valves or rings are leaking. Instructions for using this tester are found on pages 3.3 and 3.4 of this manual.

Figure 2-1. Hose Clamp Pliers.

2.1

Section 2 Special Tools

Special Tools You Can Make

Flywheel Holding T ool

Flywheel removal and reinstallation becomes a ‘‘snap’’ using a handy holding tool you can make out of a piece of an old ‘‘junk’’ flywheel ring gear as shown in Figure 2-2. Using an abrasive cut-off wheel, cut out a six tooth segment of the ring gear as shown. Grind off any burrs or sharp edges. The segment can be used in place of a strap wrench. Invert the segment and place it between the ignition module bosses on the #1 cylinder so that the tool teeth engage the ring gear teeth on the flywheel. The bosses will ‘‘lock’’ the tool and flywheel in position for loosening, tightening, or removing with a puller.

RTV Silicone Sealant

RTV (Room Temperature Vulcanizing) silicone sealant is used as a gasket between the crankcase and oil pan.

Only oxime-based, oil resistant RTV sealants, such as those listed below, are approved for use. Loctite® Nos. 5900 and 5910 are recommended for best sealing characteristics.

Loctite® Ultra Blue 587 Loctite® Ultra Copper Loctite® Ultra Black 598 Loctite® 5900 (Heavy Body) Loctite® 5910

NOTE: Always use fresh sealant. Using outdated

sealant can result in leakage.

Figure 2-2. Flywheel Holding T ool.

2.2

Section 3

Go Back

Troubleshooting

Troubleshooting Guide

When troubles occur, be sure to check the simple causes which, at first, may seem too obvious to be considered. For example, a starting problem could be caused by an empty fuel tank.

Section 3

LV560, LV625, LV675

Troubleshooting

6. Faulty spark plugs.

7. Low compression.

8. Weak spark.

9. Fuel pump malfunction causing lack of fuel.

10. Engine overheated-cooling system problem.

Some common causes of engine troubles are listed below. Use these to locate the causing factors.

Engine Cranks But Will Not Start

1. Empty fuel tank.

2. Fuel shut-off valve closed.

3. Dirt or water in the fuel system.

4. Clogged fuel line.

5. Sp ark plug lead(s) disconnected.

6. Key switch or kill switch in “off” position.

7. Faulty spark plugs.

8. Faulty ignition module.

9. Carburetor solenoid malfunction.

10. Diode in wiring harness failed in open circuit

mode.

11. Vacuum fuel pump malfunction, or oil in vacuum

hose.

12. Vacuum hose to fuel pump leaking/cracked.

13. Battery connected backwards.

Engine Start s But Does Not Keep Running

1. Restricted fuel tank cap vent.

2. Dirt or water in the fuel system.

3. Faulty choke or throttle controls.

4. Loose wires or connections that short the kill terminal of ignition module to ground.

5. Faulty cylinder head gasket.

6. Faulty carburetor.

7. V acuum fuel pump malfunction, or oil in vacuum hose.

8. Leaking/cracked vacuum hose to fuel pump.

Engines Start s Hard

1. PTO drive is engaged.

2. Dirt or water in the fuel system.

3. Clogged fuel line.

4. Loose or faulty wires or connections.

5. Faulty choke or throttle controls.

Engine Will Not Crank

1. PTO drive is engaged.

2. Battery is discharged.

3. Safety interlock switch is engaged.

4. Loose or faulty wires or connections.

5. Faulty key switch or ignition switch.

6. Faulty electric starter or solenoid.

7. Seized internal engine components.

Engine Runs But Misses

1. Dirt or water in the fuel system.

2. Spark plug lead disconnected.

3. Loose wires or connections that intermittently short the kill circuit of ignition system to ground.

4. Engine overheated-cooling system problem.

5. Faulty ignition module.

6. Faulty spark plugs.

7. Carburetor adjusted incorrectly .

8. Faulty interlock switch.

Engine Will Not Idle

1. Restricted fuel tank cap vent.

2. Dirt or water in the fuel system.

3. Faulty spark plugs.

4. Idle speed (RPM) adjusting screw improperly set.

5. Low compression.

6. Stale fuel and/or gum in carburetor.

7. Fuel supply inadequate.

8. Engine overheated-cooling system problem.

Engine Overheats

1. Air intake/grass screen, radiator , or cooling shrouds clogged.

2. Excessive engine load.

3. Low crankcase oil level.

4. High crankcase oil level.

5. Faulty carburetor.

6. Low coolant level.

3.1

Section 3 Troubleshooting

Engine Overheats (cont'd.)

7. Radiator cap faulty or loose.

8. Lean fuel mixture.

9. Water pump belt failed/off.

10. Water pump malfunction.

Engine Knocks

1. Excessive engine load.

2. Low crankcase oil level.

3. Old or improper fuel.

4. Internal wear or damage.

5. Hydraulic lifter malfunction.

Engine Loses Power

1. Low crankcase oil level.

2. High crankcase oil level.

3. Dirty air cleaner element.

4. Dirt or water in the fuel system.

5. Excessive engine load.

6. Engine overheated.

7. Faulty spark plugs.

8. Low compression

9. Exhaust restriction.

10. Low battery.

• Check for buildup of dirt and debris on the

radiators, crankcase, cooling fins, grass screen, blower housing and other external surfaces. Dirt or debris on these areas are causes of higher operating temperatures and overheating.

• Check for obvious fuel, oil, and coolant leaks, or

damaged components. Excessive oil leakage can indicate a clogged or improperly assembled breather, worn or damaged seals and gasket s, or loose or improperly torqued fasteners. Coolant leaks can cause higher operating temperatures and overheating.

• Check the air cleaner and base for damage or

indications of improper fit and seal.

• Check the air cleaner element. Look for holes,

tears, cracked or damaged sealing surfaces, or other damage that could allow unfiltered air into the engine. Also note if the element is dirty or clogged. These could indicate that the engine has been underserviced.

Engine Uses Excessive Amount Of Oil

1. Incorrect oil viscosity/type.

2. Clogged or improperly assembled breather.

3. Worn or broken piston rings.

4. Worn cylinder bore.

5. Worn valve stems or valve guides.

6. Crankcase overfilled.

Oil Leaks from Oil Seals, Gaskets

1. Crankcase breather is clogged or inoperative.

2. Loose or improperly torqued fasteners.

3. Piston blowby or leaky valves.

4. Restricted exhaust.

Engine Loses or Uses Coolant

1. Overheating-See ‘‘Engine Overheats’’ section.

2. External leakage-from a joint connection, or a component of the cooling system.

3. Internal leakage-from a head gasket, or cooling system water jacket (passage) leak.

External Engine Inspection

Before cleaning or disassembling the engine, make a thorough inspection of its external appearance and condition. This inspection can give clues to what might be found inside the engine (and the cause) when it is disassembled.

• Check the carburetor throat for dirt. Dirt in the

throat is further indication that the air cleaner is not functioning properly .

• Check the oil level. Note if the oil level is within

the operating range on the dipstick, or if it is low or overfilled.

• Check the coolant level within the reservoir and in the neck of radiator cap adapter. A low or improperly filled cooling system can cause overheating, excessive fuel consumption, and a lack of power.

• Check the condition of the oil. Drain the oil into a

container - the oil should flow freely . Check the appearance (color) of the oil, and for metal chips or foreign particles. A milky, opaque color denotes the presence of engine coolant in the crankcase oil.

Sludge is a natural by-product of combustion; a small accumulation is normal. Excessive sludge formation could indicate overrich carburetion, weak ignition, overextended oil change intervals or wrong weight or type of oil was used, to name a few.

3.2

Section 3

Troubleshooting

NOTE: It is good practice to drain oil at a location

away from the workbench. Be sure to allow ample time for complete drainage.

Cleaning the Engine

After inspecting the external condition of the engine, clean the engine thoroughly before disassembling it. Also clean individual components as the engine is disassembled. Only clean parts can be accurately inspected and gauged for wear or damage. There are many commercially available cleaners that will quickly remove grease, oil, and grime from engine parts. When such a cleaner is used, follow the manufacturer’s instructions and safety precautions carefully.

Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation. Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil.

Basic Engine Tests

Crankcase Vacuum Test

A p artial vacuum should be present in the crankcase when the engine is operating. Pressure in the crankcase (normally caused by a clogged or improperly assembled breather) can cause oil to be forced out at oil seals, gaskets, or other available spots.

Crankcase vacuum is best measured with either a water manometer (Kohler Part No. 25 761 02-S) or a vacuum gauge (Kohler Part No. 25 761 22-S). Complete instructions are provided in kits.

2. Start the engine and run at no-load high idle speed (3200 to 3750 RPM).

3. Open the clamp and note the water level in the tube.

The level in the engine side should be a minimum of 10.2 cm (4 in.) above the level in the open side.

If the level in the engine side is less than specified (low/no vacuum), or the level in the engine side is lower than the level in the open side (pressure), check for the conditions in the table below .

4. Close the shut-off clamp before stopping the engine.

Compression T est

A compression test is best performed on a warm engine. Clean any dirt or debris away from the base of the spark plugs before removing them. Be sure the choke is off, and the throttle is wide open during the test. Compression should be at least 160 psi and should not vary more than 15% between cylinders.

Cylinder Leakdown T est

A cylinder leakdown test can be a valuable alternative to a compression test. By pressurizing the combustion chamber from an external air source you can determine if the valves or rings are leaking, and how badly .

Test the crankcase vacuum with the manometer as follows:

1. Insert the stopper/hose into the oil fill hole. Leave the other tube of manometer open to atmosphere. Make sure the shut-off clamp is closed.

No Crankcase Vacuum/Pressure in Crankcase

Possible Cause Solution

1. Crankcase breather clogged or inoperative.

2. Seals and/or gaskets leaking. Loose or improperly torqued fasteners.

3. Piston blowby or leaky valves. (Confirm by inspecting components.)

4. Restricted exhaust.

Kohler Part No. 25 761 05-S is a relatively simple, inexpensive leakdown tester for small engines. The tester includes a quick disconnect for attaching the adapter hose and a holding tool.

1. Replace breather assembly (valve cover).

2. Replace all worn or damaged seals and gaskets. Make sure all fasteners are tightened securely . Use appropriate torque values and sequences when necessary .

3. Recondition piston, rings, cylinder bore, valves, and valve guides.

4. Repair/replace restricted muffler/exhaust system.

3.3

Section 3 Troubleshooting

Leakdown T est Instructions

1. Run engine 3-5 minutes to warm it up.

2. Remove spark plugs, dipstick, and air filter from engine.

3. Rotate crankshaft until piston (of cylinder being tested) is at top dead center (TDC) of compression stroke. You will need to hold the engine in this position while testing. The holding tool supplied with the tester can be used if the PTO end of the crankshaft is accessible. Slide the holding tool onto the crankshaft and adjust the set screw to fit in the key slot. Install a 3/8" breaker bar into the square hole of the holding tool, so it is perpendicular to both the holding tool and crankshaft PTO. If the flywheel end is more accessible, you can use a breaker bar and socket on the flywheel nut/screw to hold it in position. You may need an assistant to hold the breaker bar during testing.

Leakdown T est Results

Air escaping at oil fill tube .............................................................Defective rings, worn cylinder walls, or blown

Air escaping from exhaust outlet ..................................................Defective exhaust valve.

Air escaping from carburetor inlet.................................................Defective intake valve.

Gauge reading in ‘‘low’’ (green) zone............................................Piston rings and cylinder in good condition.

Gauge reading in ‘‘moderate’’ (yellow) zone..................................Engine is still usable, but there is some wear

Gauge reading in ‘‘high’’ (red) zone .............................................. Rings and/or cylinder have considerable wear.

If the engine is mounted in a piece of equipment, you may be able to hold it by clamping or wedging a driven component. Just be certain that the engine cannot rotate off of TDC in either direction.

4. Install the adapter hose into the spark plug hole, but do not attach it to the tester at this time.

5. Connect an adequate air source to the tester.

6. Turn the regulator knob in the increase (clockwise) direction until the gauge needle is in the yellow “set” area at the low end of the scale.

7. Connect tester quick-disconnect to the adapter. Note the gauge reading and listen for escaping air at the carburetor intake, exhaust outlet, and oil fill/ dipstick tube.

8. Check your test results against the table below:

head gasket.

present. Customer should start planning for overhaul or replacement.

Engine should be reconditioned or replaced.

Cooling Leakage T est

A pressure test can be performed as a simple means of determining whether the cooling system may have a problem. The test procedure, possible results, and recommended corrective action are covered in Section 7.

3.4

Air Cleaner and Air Intake System

Go Back

Air Intake System

Air Cleaner and Air Intake System

Section 4

LV560, LV625, LV675

General

All intake air , for both cooling and combustion, is drawn in through the screen in the upper blower housing.

Service Check the air intake screen daily or before starting the engine. Check for a buildup of dirt or debris on

the screen. A small accumulation can be brushed or vacuumed off with the screen in place. See Figure 4-1. For a heavier buildup, loosen the four rubber retaining straps and remove the upper blower housing/screen assembly from the engine. See Figure 4-2. Take the housing assembly outdoors or to a trash container and brush off the screen, or use compressed air and blow it off from the back side. Also check that the screen and housing are not cracked or damaged.

Figure 4-2. Removing Upper Blower Housing and Screen Assembly .

In addition to the daily check, the intake screen should have a thorough cleaning every 100 hours (more frequently under extremely dusty or dirty conditions). If necessary , the screen assembly may be separated from the upper blower housing by unsnapping it from the underside. See Figure 4-3 and 4-4.

Figure 4-1. Cleaning Air Int ake Screen.

Figure 4-3. Unsnapping Screen Assembly .

4.1

Section 4 Air Cleaner and Air Intake System

Figure 4-4. Cleaning Separated Screen Assembly.

Always reinstall the upper blower assembly after it has been removed for service. Do not operate the engine with the upper blowing housing or screen removed.

Air Cleaner

General

These engines are equipped with a replaceable, highdensity paper air cleaner element surrounded by an oil, foam precleaner, located under the upper blower housing. See Figures 4-5 and 4-6.

Service Daily or before starting the engine, remove the

upper blowing housing and check the air cleaner system. See Figures 4-5 and 4-6. Again, check for dirt or debris and clean it away . Make sure the precleaner is not damaged, ripped, or missing. The air cleaner elements must be fastened with the retainer strap, and the bottom of the element must be sealed against the air cleaner base. Make sure the base is secured tightly to the carburetor and not cracked of damaged. Also make sure the breather hose is secured to the air cleaner base and to the breather outlet fitting on the valve cover.

Figure 4-5. Air Cleaner Assembly .

Foam Precleaner

Air Cleaner Element

Retainer Strap

Air Cleaner Base

Figure 4-6. Air Cleaner System Component s.

NOTE: Damaged, worn or loose breather hose or air

cleaner components can allow unfiltered air into the engine causing premature wear and failure. Tighten or replace all loose or damaged components.

4.2

Precleaner Service If so equipped, wash and reoil the precleaner every 25 hours of operation (more often under extremely dusty

or dirty conditions). To service the precleaner perform the following steps.

1. Unhook the four retaining straps and remove the upper blower housing and screen assembly . See Figure 4-2.

Section 4

Air Cleaner and Air Intake System

2. Remove the precleaner from the paper element. See Figure 4-7.

Figure 4-7. Removing Precleaner from Paper Element.

3. Wash the precleaner in warm water with detergent. Rinse the precleaner thoroughly until all traces of detergent are eliminated. Squeeze out excess water (do not wring). Allow the precleaner to air dry .

4. Saturate the precleaner with new engine oil. Squeeze out all excess oil.

5. Reinstall the serviced precleaner over the paper element, outside the filter element retaining strap.

6. Clean the air cleaner base area, upper blower housing, and screen assembly of any debris accumulation.

7. Reinstall the upper blower housing/screen assembly , and secure with the four ret aining straps.

8. When precleaner replacement is necessary , order Kohler Part No. 66 083 03-S.

3. Unhook the filter element retaining strap and remove the paper element from the air cleaner base. See Figure 4-8.

Figure 4-8. Unhooking Retainer Strap.

4. Do not wash the paper element or use pressurized air, this will damage the element.

Replace a dirty , bent, or damaged element with a genuine Kohler element. Handle new elements carefully; do not use if the sealing surfaces are bent or damaged.

5. Clean the air cleaner base area, upper blower housing, an screen assembly of any debris accumulation.

6. Install the new paper element; Kohler Part No. 66 083 01-S and secure with the filter element retainer strap.

Disassembly/Reassembly - Standard Type

If the air cleaner base has to be removed, proceed as follows.

1. Unhook the four retaining straps and remove the upper blower housing and screen assembly . See Figure 4-2.

Paper Element Service (Standard Type)

Every 100 hours of operation (more often under extremely dusty or dirty conditions), replace the paper element.

1. Unhook the four retaining straps and remove the upper blower housing and screen assembly . See Figure 4-2.

2. Remove the precleaner from the paper element. See Figure 4-7.

2. Remove the precleaner and air cleaner element from base. See Figures 4-7 and 4-8.

3. Remove the two hex. flange nuts securing air cleaner base and mounting clamp for vacuum (fuel pump) hose onto carburetor studs. See Figure 4-9.

4.3

Section 4 Air Cleaner and Air Intake System

4. Disconnect the breather hose from the air cleaner base.

Fuel Pump Vacuum Line

Breather Hose

Figure 4-9. Base Plate Removal on Standard Type.

5. Slide the clamp and air cleaner base off the stud.

6. Reverse procedure to reassemble components. Torque the hex. flange nuts to 9.9 N·m (88 in. lb.).

Radiator Cleaning

Every time the upper blower housing assembly is removed to check or service the air cleaner, the condition of the radiators should also be checked. If the cleaning is necessary , follow the instructions in Section 7 Cooling System, found on page 7.2, "Cooling System Maintenance and Service."

4.4

Fuel System and Governor

Go Back

LV560, LV625, LV675

Section 5

Fuel System and Governor

Section 5

Description

WARNING: Explosive Fuel!

Fuel System Components

The typical fuel system and related components include the following:

• Fuel Tank

• In-line Fuel Filter

• Fuel Pump

• Carburetor

• Fuel Lines

Operation

The fuel from the tank is moved through the in-line filter and fuel lines by the fuel pump. On engines not equipped with a fuel pump, the fuel tank outlet is located above the carburetor inlet allowing gravity to feed fuel to the carburetor.

Fuel then enters the carburetor float bowl and is moved into the carburetor body . There, the fuel is mixed with air. This fuel-air mixture is then burned in the engine combustion chamber.

• Do not use gasoline left over from the previous season, to minimize gum deposits in your fuel system and to ensure easy starting.

• Do not add oil to the gasoline.

• Do not overfill the fuel tank. Leave room for the fuel to expand.

Fuel T y pe

For best results, use only clean, fresh, unleaded gasoline with a pump sticker octane rating of 87 or higher. In countries using the Research fuel rating method, it should be 90 octane minimum.

Unleaded gasoline is recommended, as it leaves less combustion chamber deposits. Leaded gasoline may be used in areas where unleaded is not available and exhaust emissions are not regulated. Be aware however, that the cylinder head will require more frequent service.

Gasoline/Alcohol blends

Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) is approved as a fuel for Kohler engines. Other gasoline/alcohol blends are not approved.

Gasoline/Ether blends

Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved as a fuel for Kohler engines. Other gasoline/ether blends are not approved.

Fuel Recommendations

General Recommendations

Purchase gasoline in small quantities and store in clean, approved containers. A container with a capacity of 2 gallons or less with a pouring spout is recommended. Such a container is easier to handle and helps eliminate spillage during refueling.

Fuel Filter

Most engines are equipped with an in-line fuel filter. Periodically inspect the filter and replace when dirty with a genuine Kohler filter.

5.1

Section 5 Fuel System and Governor

Fuel System T est s

When the engine starts hard, or turns over but will not start, it is possible that the problem is in the fuel system. To find out if the fuel system is causing the problem, perform the following tests.

Troubleshooting – Fuel System Related Causes

T est Conclusion

1. Check the following: a. Make sure the fuel tank contains clean, fresh,

proper fuel. b. Make sure the vent in fuel tank cap is open. c. Make sure the fuel valve is open. d. Make sure vacuum and fuel lines to fuel

pump are secured and in good condition.

2. Check for fuel in the combustion chamber. a. Disconnect and ground spark plug leads. b. Close the choke on the carburetor. c. Crank the engine several revolutions. d. Remove the spark plug and check for fuel at

the tip.

3. Check for fuel flow from the tank to the fuel pump. a. Remove the fuel line from the inlet fitting of

fuel pump.

b. Hold the line below the bottom of the tank.

Open the shut-off valve (if so equipped) and observe flow.

4. Check the operation of fuel pump. a. Remove the fuel line from the inlet fitting of

carburetor.

b. Crank the engine several times and observe

flow.

2. If there is fuel at the tip of the spark plug, fuel is reaching the combustion chamber.

If there is no fuel at the tip of the spark plug, check for fuel flow from the fuel tank (Test 3).

3. If fuel does flow from the line, check for faulty fuel pump (Test 4).

If fuel does not flow from the line, check the fuel tank vent, fuel pickup screen, in-line filter, shut-of f valve, and fuel line. Correct any observed problem and reconnect the line.

4. If fuel does flow from the line, check for faulty carburetor. (Refer to the "Carburetor" portions of this section).

If fuel does not flow from the line, check for a clogged fuel line. If the fuel line is unobstructed, check for overfilled crankcase and/or oil in pulse line. If none of the checks reveal the cause of the problem, replace the pump.

5.2

Section 5

Fuel System and Governor

Fuel Pump

General

These engines are equipped with an external pulse fuel pump. The pumping action is created by the oscillation of positive and negative pressures within the crankcase. This pressure is transmitted to the pulse pump through a rubber hose connected between the pump and crankcase. The pumping action causes the diaphragm on the inside of the pump to pull fuel in on its downward stroke and to push it into the carburetor on its upward stroke. Two check valves prevent fuel from going backward through the pump.

Performance

Minimum fuel delivery rate must be 7.5 L/hr. (2 gal./hr.) with a pressure at .3 p si and a fuel lif t of 24". A 1.3 L/hr . (.34 gal./hr.) fuel rate must be maintained at 5 Hz.

Replacing the Fuel Pump

Replacement pumps are available through your source of supply . To replace the pulse pump follow these steps. Note orientation of pump before removing.

1. Disconnect the fuel lines from the inlet and outlet fittings.

2. Remove the hex. flange screws (securing pump to blower housing) and fuel pump.

3. Remove the vacuum line that connects the pump to the crankcase.

4. Install a new pump using the hex. flange screws. NOTE: Make sure the orientation of the new

pump is consistent with the removed pump. Internal damage may occur if installed incorrectly .

5. Connect vacuum line between pulse pump and crankcase. Route line so there are no low spots where oil could collect.

6. Tighten the hex. flange screws to 2.3 N·m (20 in. lb.).

7. Connect the fuel lines to the inlet and outlet fittings.

Carburetor

General

Engines in this series are equipped with fixed main jet carburetors. Most applications also utilize a fuel shutoff solenoid, which is installed in place of the fuel bowl retaining screw. All carburetors feature the selfrelieving choke components shown in the exploded view on page 5.9. These carburetors include three main circuits which function as follows.

Figure 5-1. Fuel Pulse Pump Connections.

Float Circuit: Fuel level in the bowl is maintained by

the float and fuel inlet needle. The buoyant force of the float stops fuel flow when the engine is at rest. When fuel is being consumed, the float will drop and fuel pressure will push the inlet needle away from the seat, allowing more fuel to enter the bowl. When demand ceases, the buoyant force of the float will again overcome the fuel pressure and stop the flow.

5.3

Section 5 Fuel System and Governor

Slow Circuit: (Figure 5-2) At low speeds the engine operates only on the slow circuit. As a metered amount of air

is drawn through the slow air bleed jet, fuel is drawn through the main jet and further metered through the slow jet. Air and fuel are mixed in the body of the slow jet and exit to the transfer port. From the transfer port this air fuel mixture is delivered to the idle progression chamber. From the idle progression chamber the air fuel mixture is metered through the idle port passage. At low idle when the vacuum signal is weak, the air fuel mixture is controlled by the metered idle fuel passage. This mixture is then mixed with the main body of air and delivered to the engine. As the throttle plate opening increases, greater amount s of air fuel mixture are drawn in through the fixed and metered idle progression holes. As the throttle plate opens further the vacuum signal becomes great enough so the main circuit begins to work.

Air

Idle Speed (RPM) Adjustment Screw

Fuel Inlet

Fuel

Mixture

Float Valve Seat

Float Valve

Main Jet

Accelerator Pump Nozzle

Check Valve Spring

Leak Jet

Outlet Check Valve

Adjustment Screw

Diaphragm Spring

Pump Diaphragm

Inlet Check Valve

Float

Main Emulsion Hole

Slow Air Bleed Jet

Main Air Bleed Jet

Choke Valve

Bowl Vent

ACCELERAT OR PUMP

ASSEMBLY

(Some Carburetors)

Idle Progression Chamber

Slow Jet

Idle Limiter

Idle Port

Throttle Valve

Main Nozzle

Slow Passage Pipe

Main Jet

Fuel Shut-Off Solenoid with Main Jet

Jet

Capped/Preset Low (Idle) Mixture Setting

Idle Progression Holes

Figure 5-2. Slow Circuit.

5.4

Section 5

Fuel System and Governor

Main Circuit: (Figure 5-3) At high speeds the engine operates mostly on the main circuit. As a metered amount

of air is drawn through the main air bleed jet, fuel is drawn through the main jet. The air and fuel are mixed in the main nozzle and then enter the main body of air flow, where further mixing of the fuel and air t akes place. This mixture is then delivered to the combustion chamber. The carburetor has a fixed main circuit. There is no adjustment feature present.

Air

Idle Speed (RPM) Adjustment Screw

Fuel Inlet

Fuel

Mixture

Float Valve Seat

Float Valve

Main Jet

Accelerator Pump Nozzle

Check Valve Spring

Leak Jet

Outlet Check Valve

Adjustment Screw

Diaphragm Spring

Pump Diaphragm

Inlet Check Valve

Float

Main Emulsion Hole

Main Air Bleed Jet

Choke Valve

Bowl Vent

ACCELERAT OR PUMP

ASSEMBLY

(Some Carburetors)

Throttle Valve

Main Nozzle

Main Jet

Fuel Shut-Off Solenoid with Main Jet

Figure 5-3. Main Circuit.

5.5

Section 5 Fuel System and Governor

Troubleshooting – Carburetor Related Causes

Condition Possible Cause/Probable Remedy

1. Engine starts hard, runs roughly or stalls at idle speed.

2. Engine runs rich (indicated by black, sooty exhaust smoke, misfiring, loss of speed and power, governor hunting, or excessive throttle opening).

1a. Low idle speed improperly adjusted. Adjust the low idle speed

screw.

b. Low idle fuel mixture circuit blocked/restricted. Clean carburetor as

required.

2a. Clogged air cleaner. Clean or replace.

b. Choke partially closed during operation. Check the choke lever/

linkage to ensure choke is operating properly .

c. Float level too high. Separate fuel bowl from carburetor body . Free

(if stuck), or replace float.

d. Dirt under the fuel inlet needle. Remove needle; clean needle and

seat and blow with compressed air.

e. Bowl vent or air bleeds plugged. Clean vent, ports, and air bleeds.

Blow out all passages with compressed air .

f. Leaky, cracked, or damaged float. Submerge float to check for

leaks.

3. Engine runs lean (indicated by misfiring, loss of speed and power, governor hunting, or excessive throttle opening).

4. Fuel leaks from carburetor.

Troubleshooting Checklist

When the engine starts hard, runs roughly or stalls at low idle speed, check the following areas before adjusting or disassembling the carburetor.

3a. Float level too low. Separate fuel bowl from carburetor body. Free

(if stuck), or replace float.

b. Idle holes plugged; dirt in fuel delivery channels. Clean main fuel

jet and all passages; blow out with compressed air.

4a. Float stuck. See Remedy 2d.

b. Dirt under fuel inlet needle. See Remedy 2e.

c. Bowl vents plugged. Blow out with compressed air.

d. Carburetor bowl gasket leaks. Replace gasket.

• Make sure the fuel tank is filled with clean, fresh

gasoline.

• Make sure the fuel tank cap vent is not blocked

and that it is operating properly .

• Make sure the air cleaner base and carburetor

are securely fastened to the engine using gaskets in good condition.

• Make sure the air cleaner element is clean and all

air cleaner components are fastened securely.

• Make sure the ignition system, governor system,

exhaust system, and throttle and choke controls are operating properly .

• Make sure fuel is reaching the carburetor. This

includes checking the fuel shut-off valve, fuel tank filter screen, in-line fuel filter, fuel lines and fuel pump for restrictions or faulty components as necessary.

5.6

If the engine is hard-starting or runs roughly, or stalls at low idle speed, it may be necessary to service the carburetor.

Section 5

Fuel System and Governor

Fuel Shut-off Solenoid

Carburetors are equipped with a fuel shut-off solenoid, which also contains the main jet. The solenoid has a spring loaded pin which retracts when the key switch is ‘‘on’’, allowing the engine to function normally. When the key switch is turned ‘‘off’’, the pin extends and prevents fuel from entering the engine.

Below is a simple test made with the engine off, that can determine if the solenoid is functioning properly:

1. Shut off the fuel and remove the solenoid from the carburetor. When the solenoid is loosened and removed, gas will leak out of the carburetor. Have a container ready to catch the fuel.

2. Wipe the tip of the solenoid with a shop towel or blow it off with compressed air , to remove any remaining fuel. Take the solenoid to a location with good ventilation and no fuel vapors present. You will need a 12 volt power source that can be switched on and off.

3. Be sure the power source is switched off. Connect the negative power source lead to the black solenoid lead, and connect the positive power source lead to the red lead of the solenoid. Turn on the power source, while observing the pin in the center of the solenoid.

4. If the pin retracted when the power source was turned on, the solenoid is good. If the power source is turned off, the pin should return to its original position.

Adjustments

General

In compliance with government emission standards, the carburetor is calibrated to deliver the correct air-tofuel mixture to the engine under all operating conditions. Both the low and the high speed mixture circuits are pre-established and cannot be adjusted. The low idle speed (RPM) is the only adjustment available.

NOTE: Low idle speed (RPM) adjustment should be

made only after the engine has warmed up.

Adjusting Low Idle Speed (RPM) Setting

1. Start the engine and run at half throttle for 5 to 10 minutes to warm up. The engine must be warm before making final low idle speed (RPM) adjustment. Check that the throttle and choke plates can fully open.

2. Place the throttle control into the ‘‘idle’’ or ‘‘slow’’ position.

3. Set the low idle speed to 1200 RPM* (±75 RPM) by turning the low idle speed adjusting screw in

or out. Check the speed using a tachometer. *NOTE: The actual low idle speed depends on

the application. Refer to the equipment manufacturer’s recommendations. The low idle speed for basic engines is 1200 RPM. To ensure best results when setting the low idle fuel needle, the low idle speed should be 1200 RPM (± 75 RPM).

Figure 5-4. Carburetor and Solenoid.

5.7

Section 5 Fuel System and Governor

Float Replacement

If symptoms described in the carburetor troubleshooting guide indicate float level problems, remove the carburetor from the engine to check and/or replace the float. Use a Carburetor Overhaul Kit (see page 5.10) if float replacement is necessary.

1. Remove the upper blower housing and air intake components from the carburetor , as described in Section 4.

2. Disconnect the fuel inlet line from the carburetor.

3. Disconnect the governor, choke and throttle linkages from the carburetor.

4. Disconnect the lead wires from the carburetor solenoid.

5. Gently lift up on the lower blower housing directly above the carburetor and slide the carburetor off the mounting studs. Remove the fuel shut-off solenoid and drain any remaining fuel into a safe container. Remove the bowl from the carburetor body .

7. Pull the float hinge pin and remove the float, with the inlet needle attached, to inspect these parts and the needle seat. If dirty , blow out with compressed air. Replace float components as needed with kit.

8. Using new bowl gaskets, reinstall and tighten the bowl with the fuel shut-off solenoid. T ighten to

5.1-6.2 N·m (45-55 in. lb.).

9. Reinstall carburetor to engine, reconnecting the fuel line, control linkages and solenoid leads. Reinstall the air intake components, and upper blower housing assembly . Retest operation.

Disassembly

Use the following procedure to disassemble the carburetor after removing it from the engine. Refer to Figure 5-6 for identification of the component parts.

1. Remove the fuel shut-off solenoid assembly , then remove the fuel bowl and bowl gasket.

2. Pull the float hinge pin. Remove float with inlet needle attached.

16.5 mm (0.65 in.)

Turn Carburetor Upside Down

Figure 5-5. Proper Float Level.

6. Turn the carburetor upside down and check the level of the float, as shown in Figure 5-5. With the float needle valve fully seated, 16.5 mm (.65 in.) should be measured from the body to the float as indicated. Don’t attempt to adjust by bending the tab. Install a new float if level is wrong.

3. Remove the set screws holding the throttle plate to the throttle shaft. Check for any burrs on the shaft and remove them. Pull the throttle shaft from the carburetor body .

5. Remove the set screws securing the choke plate to the choke shaft assembly. Check for any burrs on the shaft and remove them. Pull the choke shaft assembly out of the carburetor body . Disassemble self-relieving parts from shaft as needed.

6. Remove the three screws holding the passage cover to the body . Remove the cover and gasket.

7. Remove the slow speed adjusting needle and spring. Except for the slow jet nozzle, main jet, and emulsion tubes, which are considered non-serviceable, the carburetor is now completely disassembled and ready for thorough inspection and cleaning.

5.8

Section 5

Fuel System and Governor

Choke Shaft

Air Filter

Choke Plate

Collar

Spring

Ring

Choke Lever

Idle Speed Spring

Set Screws

Idle Speed Screw

Throttle Shaft/ Lever

Passage Cover

Cover Retaining Screw

Fuel Bowl Gasket

Inlet Needle

Float

Shut-Off Solenoid Assembly

Red

Black

Figure 5-6. Carburetor - Exploded View.

Inspection/Repair

To clean vent ports, internal circuits etc., use a good commercially available carburetor solvent, such as Gumout™, and clean, dry compressed air to blow out internal channels and ports. Use a suitable shop rag to prevent debris from hitting someone.

Carefully inspect all components and replace those that are worn or damaged.

• Inspect the carburetor body for cracks, holes and other wear or damage.

• Inspect the float for cracks, holes, and missing or damaged float tab. Check the float hinge and pin for wear or damage.

Float Pin

Fuel Bowl

Bowl Retaining Screw Gasket

• Inspect the fuel inlet needle and seat for wear or damage.

• The choke plate is spring loaded. Check to make sure it moves freely on the shaft.

Always use new gaskets when servicing or reinstalling carburetors. Repair kits are available which include new gaskets and other components. These kits are described on the next page.

Refer to the Parts Manual for the engine being serviced to ensure the correct repair kits and replacement parts are used. The Kohler part number is stamped on the top of the carburetor mounting flange.

5.9

Section 5 Fuel System and Governor

Overhaul Kit Contains: Reassembly Procedure

Qty.

1 1 1 1 1 1 1 1 1 1 1 1

Choke Repair Kit Contains:

Qty.

1 1 2 1 1 1 1 1 1 1

Gasket Kit Contains:

Qty.

1 1 1 1 1

Solenoid Replacement Kit Contains:

Qty.

1 1 1 1 1 1

Gasket, air cleaner base Gasket, carburetor Screw, throttle adjusting Gasket, chamber screw Screw, idle adjusting Float Pin, float Inlet Needle Gasket, float chamber Spring, throttle adjusting screw Spring, idle adjusting screw Gasket, passage cover

Gasket, air cleaner base Gasket, carburetor Screw, valve set V alve, choke Filter, choke shaf t Spring, choke arm return Ring, choke lever Collar, choke Shaft, choke assembly Lever, choke assembly

Gasket, air cleaner base Gasket, carburetor Gasket, chamber screw Gasket, float chamber Gasket, passage cover

Gasket, air cleaner base Gasket, carburetor Gasket, solenoid Gasket, chamber screw Holder, solenoid V alve, solenoid

Description

Reassembly is essentially the reverse of the disassembly procedure. Use new gaskets, springs, and adjusting screws as provided in the repair kit. Also use new carburetor and intake manifold gaskets.

Governor

General

The engine is equipped with a centrifugal flyweight mechanical governor. It is designed to hold the engine speed constant under changing load conditions. The governor gear/flyweight mechanism is mounted inside the oil pan and is driven off the gear on the camshaft. The governor works as follows:

• Centrifugal force acting on the rotating governor gear assembly causes the flyweights to move outward as speed increases. Governor spring tension moves them inward as speed decreases.

• As the flyweights move outward, they cause the regulating pin to move outward.

• The regulating pin contacts the tab on the cross shaft causing the shaft to rotate.

• One end of the cross shaft protrudes through the crankcase. The rotating action of the cross shaft is transmitted to the throttle lever of the carburetor through the external linkage. See Figure 5-7.

• When the engine is at rest, and the throttle is in the “fast” position, the tension of the governor spring holds the throttle plate open. When the engine is operating, the governor gear assembly is rotating. The force applied by the regulating pin against the cross shaft tends to close the throttle plate. The governor spring tension and the force applied by the regulating pin balance each other during operation, to maintain engine speed.

• When load is applied and the engine speed and governor gear speed decreases, the governor spring tension moves the governor arm to open the throttle plate wider. This allows more fuel into the engine, increasing engine speed. As speed reaches the governed setting, the governor spring tension and the force applied by the regulating pin will again offset each other to hold a steady engine speed.

5.10

Section 5

Fuel System and Governor

1. Governor Lever Hex. Nut

2. Governor Cross Shaft

3. Governor Lever

4. Throttle Lever Linkage

5. Choke Linkage

6. Choke Actuating Lever

7. Governor Spring

8. Speed Control Bracket

9. Governor Lever (Holes for Sensitivity Adjustment)

Figure 5-7. Governor Controls and Linkage (External).

Adjustments

General

The governed speed setting is determined by the position of the throttle control. It can be variable or constant, depending on the engine application.

Initial Adjustment

Make this adjustment whenever the governor lever is loosened or removed from the cross shaft. See Figure 5-7 and adjust as follows:

1. Make sure the throttle linkage is connected to the governor lever and the throttle lever on the carburetor.

2. Loosen the hex. nut holding the governor lever to the cross shaft.

4. Insert a nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn. Tighten hex. nut to 9.9 N·m (88 in. lb.).

Sensitivity Adjustment

Governor sensitivity is adjusted by repositioning the governor spring in the holes on the governor lever. If speed surging occurs with a change in engine load, the governor is set too sensitive. If a big drop in speed occurs when normal load is applied, the governor should be set for greater sensitivity . See Figure 5-7 and adjust as follows:

1. To increase the sensitivity, move the spring closer to the governor cross shaft.

2. To decrease the sensitivity, move the spring away from the governor cross shaft.

3. Move the governor lever towards the carburetor as far as it will move (wide open throttle) and hold in position.

5.11

Section 5 Fuel System and Governor

High Idle RPM Speed Adjustment (See Figure 5-8.)

1. With the engine running, move the throttle control to fast. Use a tachometer to check the RPM speed.

2. Loosen the lock nut on the high idle adjusting screw. T urn screw outward to decrease, or inward to increase RPM speed. Check RPM with a tachometer.

Left Side Pull

Kill

Choke Control Cable

Throttle Control Cable

Kill Switch Adjusting Screw

Switch

3. When the desired RPM speed is obtained, retighten the lock nut.

NOTE: Upon establishing the high idle RPM speed,

check for a gap between the high idle control and the choke control. The gap may be greater, but no less than .5 mm (.02 in).

Choke Control Lever #1

Throttle Control Lever #2

Choke Linkage

Z Bend

Throttle Control Cable

Dual Control High Idle Lever Stop Screw "Do Not Remove"

Figure 5-8. Governor Control Connections.

High Idle Adjusting Screw

Choke Control

Cable High Idle Control Lever

Right Side Pull

5.12

Section 6

Go Back

Lubrication System

Section 6

Lubrication System

LV560, LV625, LV675

General

This engine uses a full pressure lubrication system. This system delivers oil under pressure to the crankshaft, camshaft and connecting rod bearing surfaces. In addition to lubricating the bearing surfaces, the lubrication system supplies oil to the hydraulic valve lifters.

A high-ef ficiency gerotor pump is located in the oil p an. The oil pump maintains high oil flow and oil pressure, even at low speeds and high operating temperatures. A pressure relief valve in the oil p an limits the maximum pressure of the system.

Service

The oil pan must be removed to service the oil pickup, the pressure relief valve, and the oil pump. Refer to the appropriate procedures in Sections 9 and 10.

Oil Recommendations

Using the proper type and weight of oil in the crankcase is extremely important; so is checking oil daily and changing the oil and filter regularly .

Use high-quality detergent oil of API (American

Petroleum Institute) service class SG, SH, SJ, or higher. Select the viscosity based on the air

temperature at the time of operation as shown in the following table.

NOTE: Using other than service class SG, SH, SJ, or

higher oil or extending oil change intervals longer than recommended can cause engine damage.

A logo or symbol on oil cont ainers identifies the API service class and SAE viscosity grade. See Figure 6-1.

Figure 6-1. Oil Container Logo.

The top portion of the symbol shows service class such as API SERVICE CLASS SJ. The symbol may show additional categories such as SH, CC, or CD. The center portion shows the viscosity grade such as SAE 10W-30. If the bottom portion shows ‘‘Energy Conserving,’’ it means that oil is intended to improve fuel economy in passenger car engines.

*Use of synthetic oil having 5W-20 or 5W-30 rating is acceptable, up to 4°C (40°F). **Synthetic oils will provide better starting in extreme cold below -23°C (-10°F).

Checking Oil Level

The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized. Check oil BEFORE EACH USE as follows:

1. Make sure the engine is stopped, level, and cool so the oil has had time to drain into the sump.

2. Clean the area around the oil fill cap/dipstick before removing it. This will help to keep dirt, grass clippings, etc., out of the engine.

6.1

Section 6 Lubrication System

3. Unthread and remove the oil fill cap/dipstick; wipe oil off. Reinsert the dipstick into the tube and rest the cap on the tube. Do not thread the cap onto the tube. See Figure 6-2.

Figure 6-2. Oil Fill Cap/Dipstick.

4. Remove dipstick and check oil level. The level should be between the FULL and ADD marks. If low, add oil of proper type up to the FULL mark. Reinstall oil fill cap/dipstick and thread tight.

Changing Oil and Oil Filter

Change oil and oil filter after every 200 hours or annually , whichever comes first (more often under

severe conditions). Refill with service class SG, SH, SJ or higher oil, as specified in the ‘ ‘Viscosity Grades’’ t able on previous page. Always use a genuine Kohler oil filter. Use chart below to determine part number to order.

Oil Filter Part No.

277233-S 12 050 01-S 52 050 02-S

Change the oil while the engine is still warm. The oil will flow freely and carry away more impurities. Make sure the engine is level when filling or checking oil.

Length

5" 2-1/2" 3-3/8"

‘‘Full’’ Mark

Operating

Range

Figure 6-3. Oil Level Marks on Dipstick.

NOTE: To prevent extensive engine wear or

damage, always maintain the proper oil level in the crankcase. Never operate the engine with the oil level below the ‘‘ADD’’ mark or above the ‘‘FULL’’ mark on the dipstick.

Oil Drain Plug

Oil Filter

Figure 6-4. Oil Drain Plugs and Oil Filter.

Change the oil and oil filter as follows (See Figure 6-4.):

1. To keep dirt, debris, etc., out of the engine, clean the area around the oil fill cap/dipstick before removing it.

2. Remove one of the oil drain plugs and the oil fill cap/dipstick. Be sure to allow ample time for complete drainage.

Oil Drain Plug

6.2

Section 6

Lubrication System

3. Before removing the oil filter, clean the surrounding area to keep dirt and debris out of the engine. Remove the old filter and wipe/clean the surface where the filter mounts.

4. Reinstall the drain plug. Make sure it is tightened to 13.6 N·m (10 ft. lb.).

5. Place a new oil filter in a shallow pan with the open end up. Pour new oil, of the proper type, in through the threaded center hole. Stop pouring when the oil reaches the bottom of the threads. Allow a minute or two for the oil to be absorbed by the filter material.

6. Put a drop of oil on your fingertip and wipe it on the rubber gasket.

7. Install the new oil filter to the filter adapter . Turn the oil filter clockwise until the rubber gasket contacts the surface, then tighten the filter an additional 2/3-1 turn.

8. Fill the crankcase with new oil of the proper type, to the ‘‘FULL’’ mark on the dipstick. Refer to ‘‘Oil Type’ ’ and ‘ ‘Check Oil Level’ ’ on p ages 6.1 and

6.2. Always check the level with the dip stick before adding more oil.

9. Reinstall the oil fill cap/dipstick and tighten securely by turning to the right.

Oil Sentry

General

Some engines are equipped with an optional Oil Sentry™ oil pressure switch monitor. If the oil pressure decreases below an acceptable level, the Oil Sentry will either shut off the engine or activate a warning signal, depending on the application.

The pressure switch is designed to break contact as the oil pressure increases, and make contact as the oil pressure decreases. At oil pressure above approximately 3.0/5.0 psig, the switch contacts open. Below this pressure, the switch contacts close.

On stationary or unattended applications (pumps, generators, etc.), the pressure switch can be used to ground the ignition module to stop the engine. On vehicular applications (lawn tractors, mowers, etc.) the pressure switch can only be used to activate a warning light or signal.

NOTE: Make sure the oil level is checked BEFORE

Installation

The Oil Sentry™ pressure switch is installed on the breather cover. See Figure 6-5.

™

EACH USE and is maintained up to the ‘‘FULL ’’ mark on the dipstick. This includes engines equipped with Oil Sentry™.

NOTE: To prevent extensive engine wear or

damage, always maintain the proper oil level in the crankcase. Never operate the engine with the oil level below the ‘‘ADD’’ mark or above the ‘‘FULL’’ mark on the dipstick.

Angle of Operation

This engine will operate continuously at angles up to 20º. Check oil level to assure crankcase oil level is at the ‘‘FULL ’’ mark on the dipstick.

Refer to the operating instructions of the equipment this engine powers. Because of equipment design or application, there may be more stringent restrictions regarding the angle of operation.

NOTE: Do not operate this engine continuously at

angles exceeding 20º in any direction. Engine damage could result from insufficient lubrication.

Figure 6-5. Oil Sentry™ Location.

On engines not equipped with Oil Sentry™ the installation hole is sealed with a 1/8-27 N.P.T .F. pipe plug.

6.3

Section 6 Lubrication System

To install the switch, follow these steps:

1. Apply Loctite® No. 592 Pipe Sealant with

Teflon® (or equivalent) to the threads of the

switch.

2. Install the switch into the tapped hole in the breather cover. See Figure 6-5.

3. Torque the switch to 4.5 N·m (40 in. lb.).

Testing

Compressed air, a pressure regulator, pressure gauge and a continuity tester are required to test the switch.

Breather Reed

Figure 6-6. Reed/Breather Assembly in Crankcase.

1. Connect the continuity tester to the blade terminal and the metal case of the switch. With 0 psig pressure applied to the switch, the tester should indicate continuity (switch closed).

2. Gradually increase the pressure to the switch. As pressure increases through the range of 3.0/5.0

psig, the tester should indicate a change to no continuity (switch open). The switch should

remain open as the pressure is increased to 90 psig maximum.

3. Gradually decrease the pressure through the range of 3.0/5.0 psig. The tester should indicate a change to continuity (switch closed) down to 0 psig.

4. Replace the switch if it does not operate as specified.

Crankcase Breather System

The crankcase breather system is a necessary complement to the lubrication system. To help prevent the engine oil from weeping out past shafts, seals, and gaskets during operation, it is desirable to have a low vacuum inside the crankcase. A typical crankcase breather system incorporates a simple one-way valve to provide the desired vacuum.

When the pistons move downward, crankcase air is pushed past the reeds into the cylinder head cavities. On the #2 cylinder, the upper end of the head is completely sealed by the valve cover, so a low, positive pressure is created in the head cavity . The valve cover on the #1 cylinder has an integral breather assembly to vent the air entering that head cavity . The breather inlet hole (see Figure 6-7) is positioned so most of the oil mist has already dropped out before the air enters the breather. A series of baffles and a screen separate the remaining oil as the air moves through the inside. A hose connects the breather outlet to the air cleaner base. The vented breather air is mixed with the combustion air, on it s way to the combustion chamber.

Inlet Hole

Breather Design and Function

The breather system on these engines is designed to serve two functions; prevent excess oil from accumulating in the rocker arm chambers, and maintain the desired vacuum in the crankcase. The system utilizes a spring steel reed and stop mounted in each bank of the crankcase, between the lifter bores. See Figure 6-6.

6.4

Figure 6-7. Inlet Hole in #1 Valve Cover.

The upward travel of the pistons closes the reeds and creates a low vacuum in the lower crankcase. The combination of low pressure above and low vacuum below forces any accumulated oil out of the #2 head area into the crankcase. On the #1 side, atmospheric pressure above and vacuum below, draws any oil toward the crankcase.

Section 7

Go Back

Cooling System

LV560, LV625, LV675

Section 7

Cooling System

WARNING: Explosive release of fluids from pressurized cooling system can cause serious burns!

When it is necessary to open cooling system at radiator cap, shut off engine and remove filler cap only when cool enough to touch with bare hands. Slowly loosen cap to first stop to relieve pressure before removing

completely .

This section covers the operation and servicing of the liquid cooling system.

Cooling System Components

The cooling system consists of the following components:

• Patented Circular Radiator

• Hoses

• Patented Coolant Pump with Rubber Drive Belt

• Thermostat

• Intake Manifold with Thermostat Housing

• Radiator Cap

• Radial Cooling Fan

• Overflow Reservoir

• Crankcase and Heads with Integral Cooling

Passages

Operation

The engine coolant is pumped through the cooling system by a pump, belt-driven off the camshaft. The coolant coming out of the pump is divided, and moves simultaneously through separate parallel circuits within each head and the corresponding sides of the crankcase. As the coolant moves through these passages in the engine, it absorbs heat from the engine parts. After traveling through the engine, the coolant from the two separate circuits is united and moves through the intake manifold to the lower side of the thermostat. During warm-up, the thermostat is closed, preventing circulation through the radiators. The coolant circulates through the engine only and is returned to the pump via the bypass hose. When engine heat brings the coolant up to a temperature of

79.4º C (175º F), the thermostat will begin to open, allowing coolant to circulate through the radiators. The thermostat is completely open at 90.5º C (195º F), allowing full coolant flow through the radiators. The rotation of the cooling fan, attached to the flywheel, draws in ambient air and blows it through the radiators to carry away the heat being dissipated from the coolant. After getting ‘ ‘cooled’ ’ in the radiator, the coolant is drawn into the pump from the hoses connected to the bottom of each of the radiators and circulation starts all over again.

Figure 7-1. Cooling System.

7.1

Section 7 Cooling System

Coolant Recommendations

Use equal parts of ethylene glycol (anti-freeze) and water only . Distilled or deionized water is recommended, especially in areas where the water contains a high mineral content. Propylene glycol based anti-freeze is not recommended.

DO NOT use anti-freeze with stop-leak additive(s), or put any other additives in the cooling system.

Cooling System Maintenance and Service

Maintenance

Maintaining the correct coolant level and cleaning any debris accumulation from the inlet screen and the radiator surfaces, is critical to insuring long life, proper system performance, and preventing overheating. To ensure proper air circulation, make sure the grass screen, radiators, cooling fins, and other external surfaces of the engine are kept clean at all times. Check the coolant level and clean away any debris accumulation daily or before each use. At the same time inspect the hoses and all system connections for signs of leakage.

Servicing

Every 100 hours of operation (more often under extremely dusty , dirty conditions), remove the upper blower housing. Clean the air intake screen as instructed in Section 4 and clean the external surfaces of the engine. Clean the cooling fins of the radiator with a soft brush or blow out using clean compressed air. See Figure 7-2. To avoid damaging the cooling fins, do not use a pressure washer. Make sure all parts are reinstalled before starting.

Figure 7-2. Cleaning Radiator Cooling Fins. Engine coolant should be changed every two years or

1000 hours, whichever comes first. When changing

the engine coolant, the system should also be flushed, to remove any contaminants left behind during draining. Following are recommended procedures for checking, draining, flushing, and filling the cooling system.

Checking Coolant Level

The coolant level should be checked at the overflow reservoir, located under the upper blower housing assembly.

1. Unhook the retaining straps and remove the upper blower housing and screen assembly . See Figure 7-3.

7.2

Figure 7-3. Removing Upper Blower Housing and Screen Assembly .

2. Check the coolant level in the overflow reservoir. Coolant level should be between the ‘‘Max. Level’’ and ‘‘Min. Level’’ marks on the reservoir. See Figure 7-4. Do not operate the engine with the coolant level below the ‘‘Min. Level’’ mark. Add coolant to the overflow reservoir as required.

Figure 7-4. Coolant Levels on Reservoir.

NOTE: Do not operate the engine without coolant in

the system. Do not remove the radiator cap when hot. Engine coolant is hot and under pressure and can cause severe burns. To prevent engine overheating and damage, do not exceed more than 70% anti-freeze in the cooling system.

Section 7

Cooling System

Drain the coolant into a suitable container . After the coolant has drained, apply pipe sealant with

Teflon reinstall the plugs. Torque the plugs to 13.5 N·m (120 in. lb.). Some early production engines contained steel plugs. Always use brass (sof t) plugs (Kohler Part. No. 66 139 01-S) when service is performed.

5. Loosen the two screws holding the overflow reservoir retainer bracket to the radiators. See Figure 7-6.

(not Teflon tape) to the threads and

Draining Cooling System

1. Stop the engine and let the engine cool sufficiently.

2. Unhook the retainer straps, and remove the upper blower housing and screen assembly .

3. When it is cool enough to touch with bare hands, slowly remove the radiator cap.

4. Locate and remove the coolant drain plug in the lower side of both cylinder heads. See Figure 7-5.

Coolant Drain Plugs

Figure 7-6. Loosening Retainer Bracket Mounting Screws.

6. Remove the reservoir cap. Carefully lift the top bracket up slightly , and pull the reservoir out between the bracket and fan. See Figures 7-7 and 7-8. Pour out the contents of the reservoir and wash or clean as required. Dispose of all the old coolant properly , according to local regulations.

Figure 7-5. Location of Coolant Drain Plugs.

NOTE: To avoid thread damage, do not attempt

to remove plugs when engine is hot.

Figure 7-7. Tipping Bracket A way af ter Removing Reservoir Cap.

7.3

Section 7 Cooling System

6. Fill the cooling system (See Filling the Cooling System).

7. Reinstall the upper blower housing and screen assembly.

Filling Cooling System

NOTE: To prevent engine damage, do not use anti-

freeze mixture greater than 70% ethylene glycol in the cooling system. Do not use antifreeze with stop-leak additive(s) or mix/add other additives to the cooling system. Use only ethylene glycol anti-freeze.

Figure 7-8. Removing Overflow Reservoir.

7. Reinstall the reservoir , inserting the two lower molded protrusions into the mounting holes in the lower support bracket. Engage the top bracket around the upper protrusion of the reservoir. Hold it in this position and torque the two screws to 7.3 N·m (65 in. lb.).

8. Reinstall the reservoir cap. Do not kink/pinch the hose.

9. Flush the cooling system (See Flushing Cooling System).

Flushing Cooling System

NOTE: To prevent engine damage, do not pour

water into a hot engine. Do not operate engine without coolant.

With system properly drained:

1. Fill the cooling system with clean water and a cooling system cleaner recommended for aluminum engines. Follow the directions on the container.

2 Reinstall and tighten the radiator cap.

3. Reinstall the upper blower housing assembly and secure with the retaining straps.

4. St art and run the engine five minutes, or until it reaches operating temperature.

5. Remove the upper blower housing and drain the cooling system immediately , before contaminants settle (refer to ‘‘Draining Cooling System’’).

Cooling system capacity is approximately 1.4 liters (1.47 qts.)

1. Unhook the retainer straps, and remove the upper blower housing and screen assembly .

2. Check the condition of cooling system hoses, clamps, and associated components. Replace as required.

3. Mix 50% ethylene glycol with 50% distilled or deionized water (See Coolant Recommendation). For extremely cold temperature applications or protection outside the limits listed in the Coolant Recommendation Section, refer to the anti-freeze manufacturer's instructions on the container.

4. Fill the cooling system through neck for radiator cap with the coolant mix, allow coolant to drain into the lower areas. Fill the overflow reservoir midway between the ‘‘Min. Level’’ and ‘ ‘Max. Level’’ marks, then install the radiator and reservoir caps.

5. Install the upper blower housing and screen assembly . Start engine, run for five minutes and let cool.

6. Remove the blower housing and recheck coolant level in reservoir. Coolant level should be between the ‘‘Max. Level’’ and ‘ ‘Min. Level’ ’ marks. See Figure 7-4. Add coolant if required.

7. Reinstall the upper blower housing and screen assembly.

7.4

Section 7

Cooling System

Hoses and Tubes

Hoses and tubes are used to connect the components within the cooling system. To guard against coolant loss and hose failure, the hoses, tubes and their connections should be checked regularly for leaks or damage. Loss of coolant can result in serious engine damage. Over time, engine vibration can affect hose/ joint connections, and the hoses themselves can be affected by heat and the coolant. Swelling, hardening, and/or deterioration can occur depending on the operating environment involved. Deterioration usually takes place more rapidly from the inside, making outside inspections incomplete and not always dependable. Regular outside inspection and careful inside inspection whenever connections are opened, can minimize a possible ‘‘in-service’’ problem.

Use new clamps whenever replacing a hose or a joint connection is opened, to assure proper retention and avoid leakage as a result of insufficient tension.

When making hose connections, a light coating of rubber lubricant will make assembly easier.

Thermostat Testing and Servicing

The thermostat is mounted in the intake manifold, beneath the thermostat housing. See Figure 7-9. It controls the rapid warm-up and operating temperature of the engine. If a problem is encountered which is thought to be the fault of the thermostat, it can be checked to determine its operating condition. Before removing and testing the thermostat, make sure all other possible causes such as debris accumulation, obstruction, leaks, coolant level, and damaged components are eliminated as possible causes.

To Test

Remove the thermostat from the system. Hang or suspend the thermostat by its frame in a container of water, so the thermost at does not touch the bottom of the container . Heat the water and measure the temperature (an oven thermometer can be used). The spring-loaded valve of the thermostat should begin to open at 79.4º C (175º F), and can be completely open at 90º C (195º F). If the valve opens at a temperature more than 10 degrees below the specified opening or fails to open at a temperature 10 to 15 degrees above the specified opening, the thermostat should be replaced. If the valve in the thermostat can be moved or pushed off its seat with a slight effort when the thermostat is cold, the unit may be considered defective and should be replaced. The thermostat should be replaced if operation is found to be questionable or faulty.

Installation

1. Thoroughly clean the sealing surfaces of the intake manifold and thermostat housing with an aerosol gasket remover. Make sure the sealing surfaces are clean and free of nicks or damage. Make sure the notch in the intake manifold is clean.

2. Install a new thermostat into the intake manifold, so the larger spring end is down into the well of the intake manifold. Position a new thermostat gasket on the intake manifold.

3. Install the thermostat housing so the outlet faces away from the mounting surfaces of the intake manifold.

Figure 7-9. Intake/Thermost at.

4. Install and torque the two hex. flange screws to

9.9 N·m (88 in. lb.).

5. Reconnect the radiator hose and secure with the hose clamp, if separated previously .

7.5

Section 7 Cooling System

High Temperature Sensor

A high temperature sensor may be mounted in the intake manifold and is used to activate a warning light, audible alarm, or kill the engine (depending on the application), if the safe operating temperature is exceeded. The sensor is a ‘‘normally open’’ switch which completes a circuit, when the coolant temperature reaches the rated temperature limit of the switch. For AEGIS™ engines the temperature sensor limit is 123.8º C (255º F).

If none of those are found to be the cause do the following:

1. Drain coolant from the system, so the level is lower than the installed position of the temperature sensor.

2. Remove and replace the temperature sensor. Use pipe sealant with Teflon® on the threads.

Cooling System Leakage Test

A pressure test of the cooling system can be performed as a relatively simple means of determining whether the cooling system may contain a leak. A pump/pressure type cooling system tester with the appropriate adapter may be used to check the cooling system and the radiator cap. A typical tester and adapter is shown in Figure 7-1 1.

Figure 7-10. T emperature Switch.

If the warning device activates or the engine kills, indicating an excessive operating temperature check the following:

1. Make sure all air intake and cooling surfaces are clean and free of debris accumulation.

2. After the engine has sufficiently cooled, check the coolant level in the system to make sure it is not low, or improperly mixed.

3. Check cooling system for leaks.

4. Check the thermostat, and pressure test the radiator cap.

5. Make sure the water pump and the drive belt are operational.

6. Check and inspect the wiring from the sensor for shorting or damage.

Figure 7-11. A Typical T ester and Adapter .

T est Instructions

1. With the engine cool, carefully remove the radiator cap (see Pressure Radiator Cap Section). Make sure all parts as well as the seating surfaces of the cap and adapter are clean. Install the cap on the corresponding adapter and make sure it is completely seated. Install the adapter onto the tester and lock in place. See Figure 7-12.

7.6

15 psi

Figure 7-12. Adapter Inst alled onto the Tester.

2. Pressurize the tester to 15 psi.

3. Observe the indicated pressure. It should hold steady and not decrease or leak down.

If leakage is detected, the cap should be replaced. If the tester pressure is increased to 16 psi, or above, the cap should then ‘‘bleed off’’ this excess pressure.

4. Install and lock the system adapter and tester onto the neck of the cooling system. Pressurize the tester to 14-15 psi. See Figure 7-13.

14-15 psi

Section 7

Cooling System

5. Observe the system pressure on the gauge.

Gauge holds steady pressure

If the gauge needle holds steady, there should be no serious leaks in the system. It is recommended that all connections be checked for overall condition anyway , using a flashlight.

Pressure drops slowly

If the gauge needle drops slowly it indicates the presence of a small leak or seepage. Check all components and connections for signs of leakage. Check the condition of the radiator hoses. If they swell excessively while testing the system, they may be weak and should be replaced.

Pressure drops quickly

A steady drop or loss of pressure indicates serious leakage is occurring within the system, which must be located and corrected before the engine is returned to service.

If a pressure loss is noted:

1. With pressure on the system, apply a soap/water solution and check all joint connections, hoses, and cooling system components for external leakage. Repair or replace as required.

2. Remove the dipstick and check the appearance of the oil in the crankcase. Another method would be to remove an oil drain plug and drain a small amount of oil for inspection. A milky or an opaque color, similar to chocolate milk, indicates the presence of engine coolant in the oil. Check for a blown head gasket (step 3 below) or a possible crack or internal leakage from the water jacket.

Figure 7-13. Adapter and Tester Installed.

3. Remove the spark plugs. Apply 14-15 lbs. of pressure and listen/inspect for internal coolant leakage into the cylinder/combustion chambers. This can denote a head gasket failure/leak. If required, further test by performing a ‘‘Cylinder Leakdown Test’’ as described in Section 3.

7.7

Section 7 Cooling System

7.8

Section 8

Go Back

Electrical System and Components

LV560, LV625, LV675

Section 8

Electrical System and Components

This section covers the operation, service and repair of the electrical system components. Systems and components covered in this section are:

• Sp ark Plugs

• Battery and Charging System

• Electronic CD Ignition System

• Electric Starter

Spark Plugs

Engine misfire or starting problems are often caused by a spark plug that has improper gap or is in poor condition.

The engine is equipped with the following spark plugs:

Type: The standard spark plug is a Champion

RC14YC (Kohler Part No. 66 132 01-S). Equivalent alternate brand plugs can also be used.

Gap: 0.76 mm (0.030 in.) Thread Size: 14 mm Reach: 19.1 mm (3/4 in.) Hex. Size: 16 mm (5/8 in.)

2. Remove the plug and check its condition. See “Inspection” following this procedure. Replace the plug if necessary .

NOTE: Do not clean spark plug in a machine

using abrasive grit. Some grit could remain in the spark plug and enter the engine causing extensive wear and damage.

3. Check the gap using a wire feeler gauge. Adjust the gap to 0.76 mm (0.030 in.) by carefully bending the ground electrode. See Figure 8-1.

Wire Gauge

Spark Plug

Spark Plug Service

Annually or every 200 hours of operation (whichever comes first), remove the spark plugs, check condition, and reset the gap or replace with new spark plugs as necessary . Every 500 hours of operation, replace the spark plugs. To service the spark plugs perform the

following steps:

1. Before removing each spark plug, clean the area around the base of the plug to keep dirt and debris out of the engine.

Ground Electrode

Figure 8-1. Servicing Spark Plug.

4. Reinstall the spark plug into the cylinder head and tighten to 24.4-29.8 N·m (18-22 ft. lb.).

0.76 mm (0.030 in.) Gap

8.1

Section 8 Electrical System and Components

Inspection

Inspect each spark plug as it is removed from the cylinder head. The deposits on the tip can be an indication of the general condition of the engine and/or adverse operating conditions.

Normal and fouled plugs are shown in the following photos:

Worn: On a worn plug, the center electrode will be rounded and the gap will be greater than the specified gap. Replace a worn spark plug immediately.

Normal: A plug taken from an engine operating under normal conditions will have light tan or gray colored deposits. If the center electrode is not worn, a plug in this condition could be set to the proper gap and reused.

Carbon Fouled: Soft, sooty, black deposits indicate incomplete combustion caused by a restricted air cleaner, overrich carburetion, weak ignition, or poor compression.

Wet Fouled: A wet plug is caused by excess fuel or oil in the combustion chamber. Excess fuel could be caused by a restricted air cleaner, a carburetor problem, or operating the engine with too much choke. Oil in the combustion chamber is usually caused by a restricted air cleaner, a breather problem, worn piston rings or valve guides.

8.2

Overheated: Chalky, white deposits indicate very high

combustion temperatures. This condition is usually accompanied by excessive gap erosion. Lean carburetor settings, an intake air leak, or incorrect spark timing are normal causes for high combustion temperatures.

Battery

Section 8

Electrical System and Components

1. Regularly check the level of electrolyte. Add distilled water as necessary to maintain the recommended level.

NOTE: Do not overfill the battery . Poor

performance or early failure due to loss of electrolyte will result.

2. Keep the cables, terminals, and external surfaces of the battery clean. A build-up of corrosive acid or grime on the external surfaces can cause the battery to self-discharge. Self-discharge occurs rapidly when moisture is present.

3. Wash the cables, terminals, and external surfaces with a mild baking soda and water solution. Rinse thoroughly with clear water.

NOTE: Do not allow the baking soda solution to

enter the cells as this will destroy the electrolyte.

General

A 12 volt battery with a minimum of 400 cold cranking amps should be sufficient for cranking. The actual cold cranking requirement depends on engine size, application and starting temperatures. Cranking requirements increase as temperatures decrease and battery capacity shrinks. Refer to the operating instructions of the equipment this engine powers for specific battery requirements.

If the battery charge is not sufficient to turn over the engine, recharge the battery .

Battery Maintenance

Regular maintenance is necessary to prolong battery life.

WARNING: Explosive Gas!

Batteries produce explosive hydrogen gas while being charged. To prevent a fire or explosion, charge batteries only in well ventilated areas. Keep sources of ignition away from the battery at all times. Keep batteries out of the reach of children. Remove all jewelry when servicing batteries.

Battery T est

To test the battery , you will need a DC voltmeter. Perform the following steps. See Figure 8-2:

1. Connect the voltmeter across the battery terminals.

2. Crank the engine. If the battery drops below 9 volts while cranking, the battery is too small, discharged, or faulty .

DC V oltmeter

Battery

Figure 8-2. Battery V olt age Test.

8.3

Section 8 Electrical System and Components

Electronic CD Ignition Systems

Operation of CD Ignition Systems

Capacitive Discharge with Fixed T iming

This system consists of the following components. See Figure 8-3.

• A magnet assembly which is permanently af fixed to the flywheel.

Kill Switch or ‘‘Off’’ Position of Key Switch

• Two electronic cap acitive discharge ignition modules which mount on the engine crankcase.

• A kill switch (or key switch) which grounds the modules to stop the engine.

• Two spark plugs.

The timing of the spark is controlled directly by the location of the flywheel magnet group as referenced to engine top dead center.

Ignition Modules

Spark Plug

Magnet

.008/.012 in. (.20/.30 mm) Air Gap

Figure 8-3. Capacitive Discharge Ignition System.

Red

Red Ignition Module Input

B+ and Carburetor Solenoid Input

Starter and Carburetor Solenoid Input

Red

Oil Pressure Safety Input

Violet

RectifierRegulator

Red

Green White

Spark Plugs

B+

Carburetor Solenoid

Oil Pressure Safety

White

Flywheel

Spark Advance Module (Optional)

Ignition Modules

Figure 8-4. Electronic CD Ignition System (For Customer Connected Tractor Applications).

8.4

Section 8

Electrical System and Components

SCS

Figure 8-5. Capacitive Discharge Ignition Module. Operation: As the flywheel rotates, the magnet

grouping passes the input coil (L1). The corresponding magnetic field induces energy into the input coil (L1). The resultant pulse is rectified by D1 and charges capacitor C1. As the magnet assembly completes its pass, it activates the triggering device (L2), which causes the semiconductor switch (SCS) to turn on. With the device switch “ON,” the charging capacitor (C1) is directly connected across the primary (P) of the output transformer (T1). As the cap acitor discharges, the current initiates a fast rising flux field in the transformer core. A high voltage pulse is generated from this action into the secondary winding of the transformer. This pulse is delivered to the sp ark plug gap. Ionization of the gap occurs, resulting in an arc at the plug electrodes. This spark ignites the fuel-air mixture in the combustion chamber.

Spark Plug

Reported ignition problems are most often due to poor connections. Before beginning the test procedure, check all external wiring. Be certain all ignition-related wires are connected, including the spark plug leads. Be certain all terminal connections fit snugly . Make sure the ignition switch is in the run position.

NOTE: The CD ignition systems are sensitive to

excessive load on the kill lead. If a customer complains of hard starting, low power, or misfire under load, it may be due to excessive draw on the kill circuit. Perform the preliminary test which follows.

Preliminary T est

To be certain the reported problem is in the engine ignition system, it should be isolated from the unit.

Troubleshooting CD Ignition Systems

The CD ignition systems are designed to be trouble free for the life of the engine. Other than periodically checking/replacing the spark plugs, no maintenance or timing adjustments are necessary or possible. Mechanical systems do occasionally fail or break down, however, so the following troubleshooting information is provided to help you get to the root of a reported problem.

CAUTION: High Energy Electric Spark!

The CD ignition systems produce a high energy electric spark, but the spark must be discharged, or damage to the system can result. Do not crank or run an engine with a spark plug lead disconnected. Always provide a path for the spark to discharge to ground.

1. Locate the plug connectors where the wiring harnesses from the engine and unit are joined. Separate the connectors and remove the white ‘‘kill’’ lead from the engine connector. Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground. Try to start* the engine to verify whether the reported problem is still present.

a. If the problem is gone, the electrical system on

the unit is suspect. Check the key switch, wires, connections, safety interlocks, etc.

b. If the problem persists, follow the test

procedure on the next page. Leave the kill lead isolated until all testing is completed.

*NOTE: If the engine starts or runs during any of the

testing, you may need to ground the kill lead to shut it down. Because you have interrupted the kill circuit, it may not stop with the switch.

8.5

Section 8 Electrical System and Components

Test Procedure for Standard CD Ignition

Test

1. Test for spark on both cylinders with Kohler ignition tester, Part No. 24 455 02-S. Disconnect one spark plug lead and connect it to the post terminal of the tester. Connect the clip to a good ground, not to the spark plug. Crank the engine and observe the tester spark gap. Repeat the procedure on the other cylinder. Remember to reconnect the first spark plug lead.

Ground Clip

Post T erminal

Conclusion

1. If one side is not firing, check all wiring, connections, and terminations on that side. If wiring is okay , replace ignition module and retest for spark.

If the tester shows spark, but the engine misses or won't run on that cylinder, try a new sp ark plug.

If neither side is firing, recheck position of ignition switch and check for shorted kill lead.

Battery Charging System

General

Most engines are equipped with a 15 amp regulated battery charging system. Some have a 25 amp regulated battery charging system. See Figure 8-6 for the 15/25 amp system diagram. Some have a 3 amp unregulated system with optional 70 watt lighting circuit. See Figure 8-7 for 3 amp system diagram.

NOTE: Observe the following guidelines to avoid

damage to the electrical system and components:

• Make sure the battery polarity is correct. A negative (-) ground system is used.

• Disconnect the plug from the rectifier-regulator and the battery cables before doing electric welding on the equipment powered by the engine.

• Prevent the stator (AC) leads from touching or shorting while the engine is running. This could damage the stator .

Wiring Color Codes

B L R Y W P O L/R

Black Blue Red Yellow White Purple Orange Blue/Red

8.6

CONNECTOR LAYOUT

Starter (L/R)

Run (R)

Ignition Kill (W)

Accessory (Y)

Battery (R)

Key Switch Ground (B)

Run

Ground

Ignition Kill

Starter

Battery

Accessory

Key Switch

Section 8

Electrical System and Components

Oil Sentry Light

Oil Pressure

Switch

Accessory Terminal (+) (Y)

Battery (+) (P)

Ignition Kill

Carburetor

Assembly

Carburetor Solenoid

Regulator Connector

Ground B

Regulator

Rectifier

Intake

Manifold

Screw

Coolant Temp. Overheat Alarm

Coolant Temp. Gauge

B+

Stator AC (W)

Blower Housing

Safety Switch

Intake

Manifold

Screw

Battery

Starter Solenoid Tang

Starter Solenoid Stud

Connector

Fuse

Starter Assembly

Figure 8-6. Wiring Diagram - 15/20/25 amp Regulated Battery Charging System.

Ignition Module

Flywheel

Stator

Assembly

Spark Plug #2 Cylinder

Coolant

Temp. Switch

Ignition Module

Spark Plug #1 Cylinder

Ground-To-Kill Lead (White)

Light

GND

Spark

Plug

Ignition Modules

Key Switch

Optional Oil Sentry

Optional Oil Sentry Switch (Indicator Light)

Optional Fuse

Optional Ammeter

Lights

Diode

Switch (Shutdown)

12 V. Battery

Solenoid

Starter

Figure 8-7 Wiring Diagram - 3 amp Unregulated Battery Charging System/70 Watt Lighting.

Spark Plug

3 Amp/70 Watt Flywheel Stator

8.7

Section 8 Electrical System and Components

Rectifier-Regulator

Connector

B+

Figure 8-8. 15/20/25 amp Stator and Rectifier-Regulator .

Lighting Lead (Yellow)

Diode

Charging Lead (Black)

15 Amp Stator

AC Leads

3 Amp Charging St ator

Figure 8-9. 3 amp/70 Watt St ator.

8.8

Lighting Stator

Stator

The stator is mounted on the crankcase behind the flywheel. Should the stator have to be replaced, follow the procedures in Section 9 - “Disassembly .”

Rectifier-Regulator

The rectifier-regulator is mounted inside the lower blower housing. See Figure 8-10. To replace it; remove the upper blower housing, disconnect the connector plug, remove the single mounting screw with the ground lead and lift out the rectifier-regulator.

NOTE: When installing the rectifier-regulator , make

sure the cooling fins are "up", and the harness wires remain in the channel of the lower blower housing, with adequate clearance from the flywheel.

DC V oltmeter

Section 8

Electrical System and Components

Figure 8-10. Rectifier-Regulator.

(–)

Battery

Figure 8-11. Connections for Testing Charging System.

(+)

Rectifier-Regulator

Flywheel Stator

Ammeter

8.9

Section 8 Electrical System and Components

Troubleshooting Guide

15/20/25 amp Battery Charging Systems

If it is difficult to keep the battery charged, or the battery overcharges, the problem is usually with the charging system or the battery .

NOTE: Always zero ohmmeter on each scale before testing to ensure accurate readings. Volt age test s

should be made with the engine running at 3600 RPM - no load. The battery must be fully charged.

Problem

Charge

Battery

Test

1. Trace B+ lead from rectifier-regulator to key switch, or other accessible connection. Disconnect it from switch or connection. Connect an ammeter from loose end of B+ lead to positive terminal of battery. Connect DC voltmeter from loose end of B+ lead to negative terminal of battery. See Figure 8-11. With engine running at 3600 RPM, read voltage on voltmeter.

If voltage is 13.8 volts or more, place a minimum load of 5 amps* on battery to reduce voltage. Observe ammeter.

*NOTE: Turn on lights (if 60 watts or more) or

place a 2.5 ohm, 100 watt resistor across battery terminals.

2. Remove connector from rectifier-regulator. With engine running at 3600 RPM, measure AC voltage across stator leads using an AC voltmeter.

3a. With engine stopped, measure the resistance

across stator leads using an ohmmeter.

Conclusion

1. If voltage is 13.8-14.7 and charge rate increases when load is applied, the charging system is OK and battery was fully charged.

If voltage is less than 13.8, or charge rate does not increase when load is applied, test stator (Tests 2 and 3).

2. If voltage is 28 volts or more, stator is OK. Rectifier-regulator is faulty. Replace the rectifier-regulator.

If voltage is less than 28 volts, stator is probably faulty and should be replaced. Test stator further using an ohmmeter (Test 3).

3a. If resistance is 0.064/0.2 ohms, the stator is OK.

If the resistance is infinity ohms, stator is open. Replace stator.

Battery

Continuously

Charges at

High Rate

8.10

3b. With the engine stopped, measure the

resistance from each stator lead to ground using an ohmmeter.

1. Perform same test as step 1 above.

3b. If the resistance is infinity ohms (no continuity),

the stator is OK (not shorted to ground). If resistance (or continuity) is measured, the

stator leads are shorted to ground. Replace stator.

1. If the voltage is 14.7 volts or less the charging system is OK. The battery is unable to hold a charge. Service battery or replace as necessary.

If voltage is more than 14.7 volts, the rectifierregulator is faulty. Replace rectifier-regulator.

Section 8

Electrical System and Components

Troubleshooting Guide

3 amp Battery Charging System with 70 Watt Lighting St ator

NOTE: Zero ohmmeters on each scale to ensure accurate readings. Voltage test s should be made with engine

running at 3000 RPM - no load. Battery must be fully charged.

Problem

Charge

Battery

Test

1. With engine running at 3000 RPM, measure voltage across battery terminals using a DC voltmeter.

2. Disconnect the charging lead from battery. With engine running at 3000 RPM, measure

voltage from charging lead to ground using a DC voltmeter.

3. With charging lead disconnected from battery and engine stopped, measure resistance from charging lead to ground using an ohmmeter. Note reading.

Reverse the leads and measure resistance again.

In one direction, the resistance should be infinity ohms (open circuit). With the leads reversed, some resistance should be measured (about midscale on Rx1 range).

4. Cut the sleeving on the charging lead to expose the diode connections.

Conclusion

1. If voltage is more than 12.5 volts, charging system is OK.

If voltage is 12.5 volts or less, the stator or diode is probably faulty. Test the stator and diode (Tests 2, 3 and 4).

2. If voltage is 28 volts or more, stator winding is OK.

If voltage is less than 28 volts, test stator using an ohmmeter (Tests 3 and 4).

3. If resistance is low in both directions, the diode is shorted. Replace the diode.

If resistance is high in both directions, the diode or stator winding is open. (Use Test 4.)

4. If resistance is approximately 1.07 ohms, stator winding is OK.

Lights

Measure the resistance from the stator side of diode to ground using an ohmmeter.

1. Make sure lights are not burned out.

2. Disconnect the lighting lead from the wiring harness.

With engine running at 3000 RPM, measure voltage from lighting lead to ground using an AC voltmeter.

3. With engine stopped, measure the resistance of stator from lighting lead to ground using an ohmmeter.

If resistance is 0 ohms, stator winding is shorted. Replace stator.

If resistance is infinity ohms, stator winding or lead is open. Replace stator.

1. Replace burned out lights.

2. If voltage is 15 volts or more, stator is OK. Check for loose connections or shorts in wiring harness.

If voltage is less than 15 volts, test stator using an ohmmeter (Test 3).

3. If resistance is approximately 0.4 ohms, stator is OK.

If resistance is 0 ohms, stator is shorted. Replace stator.

If resistance is infinity ohms, stator or lighting lead is open. Replace stator.

8.11

Section 8 Electrical System and Components

Solenoid Shift Electric Starters

The following subsection covers the solenoid shift style electric starters. Some of the information in the preceding subsection relates also to this style of starter , so it is not repeated here. A Nippendenso or Delco-Remy solenoid shift starter may be used. The Nippendenso starter is covered beginning on Page 8.21. The Delco Remy starter is covered beginning on page 8.13.

Starting Motor Precautions

NOTE: Do not crank the engine continuously for

more than 10 seconds at a time. If the engine does not start, allow a 60 second cool-down period between starting attempts. Failure to follow these guidelines can burn out the starter motor.

NOTE: If the starter does not crank the engine, shut

off the starter immediately. Do not make further attempts to start the engine until the condition is corrected.

NOTE: Do not drop the starter or strike the starter

frame. Doing so can damage the starter .

Starter Removal and Inst allation

Refer to the “Disassembly” and “Reassembly” Sections for starter removal and installation procedures.

Troubleshooting Guide – Starting Difficulties

Problem

Starter

Does Not

Energize

Starter Energizes But Turns

Slowly

Possible Fault

Battery

Wiring

Starter Switch

or Solenoid

Battery

Brushes

Transmission

Engine

1. Check the specific gravity of battery . If low, recharge or replace battery as necessary .

1. Clean corroded connections and tighten loose connections.

2. Replace wires in poor condition and with frayed or broken insulation.

1. Bypass the switch or solenoid with a jumper wire. If starter cranks normally , replace the faulty component.

1. Check the specific gravity of battery. If low, recharge or replace battery as necessary .

2. Battery too small, must be at least 400 cold cranking amps.

1. Check for excessively dirty or worn brushes and commutator. Clean using a coarse cloth (not emery cloth).

2. Replace brushes if excessively or unevenly worn.

1. Make sure the clutch or transmission is disengaged or placed in neutral. This is especially important on equipment with hydrostatic drive. The transmission must be exactly in neutral to prevent resistance which could keep the engine from starting.

2. Check for seized engine components such as the bearings, connecting rod, and piston.

Correction

8.12

Section 8

Electrical System and Components

Delco-Remy Starters

Figure 8-12.

Starter Disassembly

1. Remove the hex. nut and disconnect the positive (+) brush lead/bracket from the solenoid terminal.

2. Remove the three screws securing the solenoid to the starter . Remove the solenoid and plunger spring from the drive end cap. See Figure 8-13 and 8-14.

3. Lift and unhook the plunger assembly from the drive lever. Remove the gasket from the recess in the housing. See Figure 8-15.

Figure 8-15. Removing Plunger.

4. Remove the two thru (larger) bolts. See Figure 8-16.

Figure 8-13. Removing Solenoid Screws.

Figure 8-16. Removing Thru Bolts.

Figure 8-14. Solenoid Removed from Starter.

8.13

Section 8 Electrical System and Components

5. Remove the commutator end plate assembly , containing the brush holder, brushes, springs, and locking caps. Remove the thrust washer from inside the commutator end. See Figure 8-17.

Figure 8-19.

8. Take out the drive lever and pull the armature out from the drive end cap. See Figure 8-20.

Figure 8-17. Removing Commutator End Plate Assembly .

6. Remove the frame from the armature and drive end cap. See Figure 8-18.

Figure 8-18. Starter Frame Removed.

7. Remove the drive lever pivot bushing and backing

plate from the end cap. See Figure 8-19.

9. Remove the thrust washer from the armature shaft. See Figure 8-20.

Figure 8-20. Armature and Lever Removed.

10. Push the stop collar down to expose the retaining ring. See Figure 8-21.

8.14

Figure 8-21. Retaining Ring Detail.

Section 8

Electrical System and Components

11. Remove the retainer from the armature shaft. Save the stop collar.

NOTE: Do not reuse the old retainer .

Figure 8-22. Removing Retaining Ring.

12. Remove the drive pinion assembly from the armature.

13. Clean the parts as required.

NOTE: Do not soak the armature or use solvent

when cleaning. Wash and dry/clean using a soft cloth, or compressed air.

Screw

Collar

Ring Stop

Drive

Armature

Washer

Tube

Plunger

Spring

Lever Plate

Plug Solenoid

Frame & Field

Brush Holder Nut

CE Frame

Screw

Figure 8-23. Delco-Remy Starter .

Bolt

8.15

Section 8 Electrical System and Components

Inspection

Drive Pinion

Check and inspect the following areas:

a. The pinion teeth for abnormal wear or

damage.

b. The O.D. surface between the pinion and the

clutch mechanism for nicks, or irregularities which could cause seal damage.

c. Check the drive clutch by holding the clutch

housing and rotating the pinion. Pinion should rotate in one direction only .

Brushes and Springs

Inspect both the springs and brushes for wear, fatigue, or damage. Measure the length of each brush. The minimum length for each brush is 7.6 mm (.300 in.). See Figure 8-24. Replace the brushes if they are

worn undersize, or their condition is questionable.

2. Use an ohmmeter set to the Rx1 scale. Touch the probes between two different segments of the commutator , and check for continuity. See Figure 8-26. Test all the segments. Continuity must exist between all or the armature is bad.

Insulation Check

Armature Coil

Figure 8-26. Checking Armature.

3. Check for continuity between the armature coil segments and the commutator segments. See Figure 8-26. There should be no continuity. If continuity exists between any two, the armature is bad.

Continuity Check

Wear limit length:

1.6 mm (.300)

Figure 8-24. Checking Brushes.

Armature

1. Clean and inspect the commutator (outer surface). The mica insulation of the commutator must be lower than the O.D. surface (undercut) to ensure proper operation of the commutator . See Figure 8-25.

Commutator O.D.

Mica Insulation

4. Check the armature windings/insulation for shorting.

Shift Fork

Check that the shift fork is complete, and the pivot and contact areas are not excessively worn, cracked or broken.

Brush Replacement

The brushes and springs are serviced as a set (4). Use Brush and Spring Kit, Kohler Part No. 25 221 01-S, if replacement is necessary.

1. Perform steps 1-5 in “St arter Disassembly.”

Figure 8-25. Commutator Mica Inspection.

8.16

Section 8

Electrical System and Components

2. Remove the two screws securing the brush holder assembly to the end cap (plate). Note the orientation for reassembly later . See Figure 8-27. Discard the old brush holder assembly .

Figure 8-27. Removing Brush Holder.

3. Clean the component parts as required.

4. The new brushes and springs come preassembled in a brush holder with a protective sleeve that will also serve as an installation tool. See Figure 8-28.

Starter Reassembly

1. Apply new drive lubricant (Kohler Part No. 52 357 02-S) to the armature shaft splines. Install the drive pinion onto the armature shaft.

2. Install and assemble the stop collar/retainer assembly. a. Install the stop collar down onto the armature

shaft with the counter bore (recess) up.

b. Install a new retainer in the larger (rear) groove

of the armature shaft. Squeeze with a pliers to compress it in the groove.

c. Slide the stop collar up and lock it into place,

so the recess surrounds the retainer in the groove. If necessary , rotate the pinion outward on the armature splines against the retainer to help seat the collar around the retainer .

Figure 8-28. Service Brush Kit.

5. Perform Steps 10-13 in the “Starter Reassembly” sequence. (Installation must be done after the armature, drive lever and frame are installed, if the starter has been disassembled.)

Starter Service

Clean the drive lever and armature shaft. Apply Kohler electric starter drive lubricant Part No. 52 357 02-S to the lever and shaft (Versilube G322L or Mobil Temp SHC 32). Clean and check the other starter parts for wear or damage as required.

Figure 8-29. Installing Stop Collar and Ret ainer.

NOTE: Always use a new retainer . Do not reuse old

retainers, which have been removed.

3. Install the offset thrust (stop) washer so the smaller “offset” of washer faces the retainer/collar. See Figure 8-30.

Figure 8-30. Installing Thrust Washer.

8.17

Section 8 Electrical System and Components

4. Apply a small amount of oil to the bearing in the drive end cap, and install the armature with the drive pinion.

5. Lubricate the fork end and center pivot of the drive lever with drive lubricant (Kohler Part No. 52 357 02-S). Position the fork end into the space between the captured washer and the rear of the pinion.

6. Slide the armature into the drive end cap, and at the same time seat the drive lever into the housing.

NOTE: Correctly installed, the center pivot section of

the drive lever will be flush or below the machined surface of the housing which receives the backup washer. See Figure 8-31.

Figure 8-31. Installing Armature and Pivot Lever .

7. Install the backup washer followed by the rubber grommet, into the matching recess of the drive end cap. The molded recesses in the grommet should be “out”, matching and aligned with those in the end cap. See Figure 8-32.

Figure 8-32. Installing Backup W asher and Grommet.

8. Install the frame with the small notch forward, onto the armature and drive end cap. Align the notch with the corresponding section in the rubber grommet. Install the drain tube in rear cutout, if it was removed previously . See Figure 8-33.

Figure 8-33. Installing Frame and Drain Tube.

9. Install the flat thrust washer onto the commutator

end of the armature shaft. See Figure 8-34.

8.18

Figure 8-34. Installing Thrust Washer.

Section 8

Electrical System and Components

10. Starter reassembly when replacing the Brushes/ Brush Holder Assembly:

a. Hold the starter assembly vertically on the end

housing, and carefully position the assembled brush holder assembly with the supplied protective tube, against the end of the commutator/armature. The mounting screw holes in the metal clips must be “up/out.” Slide the brush holder assembly down into place around the commutator , and inst all the positive (+) brush lead grommet in the cutout of the frame. See Figure 8-35. Save the protective tube, it may be used for future servicing.

b. Position each of the brushes back in their slots

so they are flush with the I.D. of the brush holder assembly . Insert Brush Installation Tool No. KO3226-1 (w/extension), or use the tube described above from a prior brush installation, through the brush holder assembly , so the holes in the metal mounting clips are “up/out.”

c. Install the brush springs and snap on the four

retainer caps. See Figure 8-37.

Figure 8-35. Installing Brush Holder Assembly with Supplied T ube.

St arter reassembly when not replacing the Brushes/Brush Holder Assembly:

a. Carefully unhook the retaining caps from over

each of the brush assemblies. Do not lose the springs.

Figure 8-36. Removing Retaining Clips.

Figure 8-37. Brush Installation Tool with Extension.

d. Hold the starter assembly vertically on the end

housing, and carefully place the tool (w/ extension) and assembled original brush holder assembly onto the end of the armature shaft. Slide the brush holder assembly down into place around the commutator , inst all the positive (+) brush lead grommet in the cutout of the frame. See Figure 8-38.

Figure 8-38. Installing Brush Holder Assembly using T ool with Extension.

8.19

Section 8 Electrical System and Components

11. Install the end cap onto armature and frame, aligning the thin raised rib in the end cap with the corresponding slot in the grommet of the positive (+) brush lead.

12. Install the two thru bolts, and the two brush holder mounting screws. Torque the thru bolts to 5.6-9.0 N•m (49-79 in. lb.). Torque the brush holder mounting screws to 2.5-3.3 N•m (22-29 in. lb.). See Figures 8-39 and 8-40.

Figure 8-41. Installing Solenoid Screws.

14. Connect the positive (+) brush lead/bracket to the solenoid and secure with the hex. nut. Torque the nut to 8-11 N•m (71-97 in. lb.), do not overtighten. See Figure 8-42.

Figure 8-39. Torquing Thru Bolts.

Figure 8-40. T orquing Brush Holder Screws.

13. Hook the plunger behind the upper end of the drive lever, and inst all the spring into the solenoid. Insert the three mounting screws through the holes in the drive end cap. Use these to hold the solenoid gasket in position, then mount the solenoid. Torque the screws to 4.0-6.0 N•m

(35-53 in. lb.). See Figure 8-41.

Figure 8-42. Positive (+) Brush Lead Connection.

Completed Starter Photo

8.20

Figure 8-43. Delco-Remy Starter.

Nut

Section 8

Electrical System and Components

Drive End Cap

Frame

Starter Assembly

Drive Lever

Dust Cover

Solenoid

Nut

Armature

Front Stop Collar

Retainer

Rear Stop Collar

Drive Pinion

Wire

Brushes Brush

Holder

Brush Spring

Insulator

Commutator End Cap

Thru Bolt

Figure 8-44. Nippendenso Solenoid Shift St arter .

Operation – Solenoid Shift St arter

When power is applied to the starter the electric solenoid moves the drive pinion out onto the drive shaft and into mesh with the flywheel ring gear. When the pinion reaches the end of the drive shaft it rotates the flywheel and cranks the engine.

When the engine starts and the start switch is released, the solenoid is deactivated, the drive lever moves back, and the drive pinion moves out of mesh with the ring gear, into the retracted position.

Starter Disassembly

1. Disconnect the wire from the solenoid.

2. Remove the hex. nuts securing the solenoid, and remove the solenoid from the starter assembly .

3. Remove the two thru bolts.

4. Remove the commutator end cap.

5. Remove the insulator and brush springs from the brush spring holder.

6. Remove the armature from the frame.

7. Remove the drive lever and armature from the drive end cap.

8.21

Section 8 Electrical System and Components

8. The outward travel of the drive pinion is controlled by a snap ring, installed in a groove in the armature shaft, and a two-piece stop collar . The snap ring fits into a recess in the pinion (lower) stop collar, which locks it in the groove (see Figure 8-45). The thrust receiving (upper) stop collar has a projecting flange, which rests on the snap ring, and it serves as a thrust washer to protect the front armature bushing in the drive end cap.

Thrust Receiving Stop Collar

Armature Snap Ring Pinion Shaft

Figure 8-45. Stop Collars and Retainer.

Side the thrust receiving stop collar off the end of the armature shaft. Place the open end of a 13 mm or 1/2" deep socket over the end of the armature shaft, so the end of the socket is against the top of the pinion stop collar. Tap the other end of the socket with a small hammer of soft head mallet to separate the collar from the snap ring. See Figure 8-46.

Figure 8-46. Separating the Pinion Stop Collar from the Retainer .

9. Remove and discard the snap ring, then slide the pinion stop collar off of the armature shaft.

10. Remove the pinion from the splines.

Pinion Stop Collar

Plastic Hammer

1/2" (13 mm) Deep Socket

Pinion Stop Collar

Brush Replacement

The brushes in the starter are part of the starter frame. Brush kit Part No. 52 221 01-S contains four replacement brushes and springs. If replacement is necessary , all four brushes should be replaced.

1. Remove brushes from brush holder, and remove brush holder from frame.

2. Cut the brush lead wire at the edge of the post with a pair of side cutters.

3. File off burrs on the post.

4. The replacement brushes have a solid portion on them which should be crimped on the post.

5. Solder the crimped portion to the post.

6. Replace the brush holder in the frame and place the brushes in the brush holder. Reinst all the springs.

Starter Service

Every 500 hours of operation (or annually, whichever comes first), solenoid shift starters must be disassembled, cleaned and relubricated. Apply Kohler solenoid shift starter lubricant (Part No. 52 357 02-S) to lever and shaft. Failure to do so could result in an accumulation of dirt or debris that might prevent the engine from starting and could cause damage to the starter or flywheel. Service may be necessary more frequently under dusty or dirty conditions.

Starter Reassembly

1. Apply new drive lubricant (Kohler Part No. 52 357 02-S) to the armature shaft splines and drive lever. Inst all the pinion onto the splines.

2. Slide the pinion stop collar onto the armature shaft with the recessed side up. Install a new snap ring in the armature shaft groove. Squeeze it with a pliers, to seat/compress it in the groove.

3. Clamp a Vise-Grip®or other locking jaw pliers onto the pinion, between the drive gear and the clutch. Turn the pinion out on the splines until it contact s the pinion stop collar and pushes it up into position around the snap ring. Slide the thrust receiving stop collar onto the armature shaft with the flange toward the snap ring. Apply a coating of drive lubricant to the stop collars.

4. Reassemble the remaining components of the starter in reverse order from disassembly.

8.22

Section 9

Go Back

LV560, LV625, LV675

Disassembly

Section 9

Disassembly

WARNING: Accident al Starts!

General

Clean all parts thoroughly as the engine is disassembled. Only clean parts can be accurately inspected and gauged for wear or damage. There are many commercially available cleaners that will quickly remove grease, oil and grime from engine parts. When such a cleaner is used, follow the manufacturer’s instructions and safety precautions carefully .

Typical Disassembly Sequence

The following sequence is suggested for complete engine disassembly . The sequence can be varied to accommodate options or special equipment.

1. Disconnect battery and spark plug leads.

2. Turn fuel shut-off valve to ‘ ‘of f’’ position.

3. Drain oil from crankcase and remove oil filter.

4. Remove upper blower housing assembly .

5. Remove muffler.

6. Drain coolant from cooling system.

7. Remove fuel pump.

8. Remove air cleaner base.

9. Remove carburetor.

10. Remove control bracket assembly and external governor lever.

1 1 . Remove electric starter.

12. Remove flywheel fan and blocking plates.

13. Remove overflow reservoir.

14. Remove ignition modules.

15. Remove flywheel.

16. Remove radiators and cooling system.

17. Remove stator and rectifier-regulator.

18. Remove cam pulley and water pump belt.

19. Remove water pump and transfer tube.

20. Remove by-pass hose and wiring harness.

21. Remove intake manifold, temperature sensor, and thermostat.

22. Remove lower blower housing and oil fill/dipstick tube.

23. Remove Oil Sentry™ (if so equipped).

24. Remove breather cover.

25. Remove spark plugs.

26. Remove valve covers.

27. Remove cylinder heads and hydraulic lifters.

28. Remove oil pan assembly.

29. Remove camshaft.

30. Remove governor cross shaft.

31. Remove connecting rods with pistons and rings.

32. Remove crankshaft.

Disconnect Battery and Spark Plug Leads

1. Disconnect the leads from the spark plugs. See Figure 9-1. Disconnect the battery cables from the battery , starting with the negative (-) cable.

NOTE: Pull on boot only , to prevent damage to

spark plug lead.

Figure 9-1. Disconnecting Spark Plug Leads.

Spark Plug Lead

9.1

Section 9 Disassembly

Shut Off Fuel Supply

Drain Oil From Crankcase and Remove Oil Filter

1. Remove the dipstick and one of the oil drain plugs. See Figures 9-2 and 9-3.

Figure 9-2. Removing Oil Fill Cap/Dipstick.

3. There is likely to be some oil left in the filter. Place a shallow pan under the filter pad and filter to catch the overflow. Remove the oil filter by turning it in a counterclockwise direction with a filter wrench. Discard filter. See Figure 9-4.

Figure 9-4. Removing Oil Filter.

Remove Upper Blower Housing Assembly

1. Unhook the four retainer straps and lift off the upper housing and screen assembly . The screen assembly may be unsnapped from the underside and separated for servicing if required. See Figures 9-5 and 9-6.

Oil Drain Plug

Oil Filter

Figure 9-3. Oil Drain Plugs and Oil Filter.

2. Allow ample time for the oil to drain from the crankcase and oil filter.

9.2

Oil Drain Plug

Figure 9-5. Removing Upper Blower Housing.

Figure 9-6. Separating Screen from Housing.

Remove Muffler

1. Remove the muffler or exhaust system and attaching hardware from the engine. See Figure 9-7.

Section 9

Disassembly

2. Carefully remove the coolant drain plugs in the lower side of both cylinder heads. See Figure 9-9. Drain the coolant into a suitable container . Early production units contained steel plugs, remove only when the cylinders are cool. Replace with brass (soft) plugs on reassembly , Kohler Part No. 66 139 01-S.

Figure 9-7. Removing Muffler.

Drain Cooling System

1. Make sure the engine is cool. Slowly remove the radiator cap. See Figure 9-8.

Figure 9-9. Location of Coolant Drain Plugs.

Remove Fuel Pump

1. Disconnect the pulse (vacuum) line from the crankcase fitting. See Figure 9-10.

Figure 9-10. Disconnecting Pulse Line from Fitting.

Figure 9-8. Removing Radiator Cap.

9.3

Section 9 Disassembly

2. Disconnect the fuel lines at the inlet of the carburetor, and the in-line fuel filter. See Figure 9-1 1.

Figure 9-11. Removing Fuel Line at Carburetor.

3. Remove the two hex. flange screws securing the fuel pump to the blower housing and remove the pump and lines as an assembly . Slide the fuel line out of the clip attached to mounting stud. See Figure 9-12.

Remove Air Cleaner Base

1. Disconnect the breather hose from the air cleaner base. See Figure 9-13.

Figure 9-13. Removing Breather Hose from Air Cleaner Base.

2. Remove the two hex. flange nuts securing the air cleaner base assembly to the carburetor studs. See Figure 9-14.

Figure 9-12. Removing Fuel Pump.

9.4

Figure 9-14. Removing Air Cleaner Base.

3. Remove clamp and air cleaner base (with element) from the studs.

Section 9

Disassembly

Remove Carburetor

1. Disconnect the fuel solenoid leads (most models) from the wiring harness.

2. Disconnect the dampening spring and throttle linkage from the governor arm. Remove the black bushing, and clip it back onto the linkage, so it does not get lost. See Figure 9-15.

Figure 9-15. Removing Throttle Linkage, Dampening Spring, and Black Bushing.

Remove Control Bracket Assembly and External Governor Lever

1. Disconnect any remote throttle and/or choke control cables connected to the throttle control bracket.

2. Loosen the hex. flange nut on the clamp screw securing the governor lever to the cross shaft. See Figure 9-17.

Figure 9-17. Loosening Governor Lever Clamp Nut.

3. Gently lift up on the lower blower housing, directly above the carburetor, and slide the carburetor outward on the studs. See Figure 9-16.

Figure 9-16. Lifting Edge of Lower Housing/ Removing Carburetor.

4. Disconnect the choke linkage from the carburetor, then remove the carburetor and gaskets from the studs.

3. Remove the four hex. flange screws securing the throttle control bracket to the cylinder heads. See Figure 9-18.

Figure 9-18. Removing the Four Screws from Main Throttle Bracket.

9.5

Section 9 Disassembly

4. Remove the throttle control bracket, governor lever, and governor spring as an assembly. See Figure 9-19.

Figure 9-19. Removing Main Bracket and Governor Lever.

Remove Electric Starter

1. Disconnect the leads from the starter .

2. Remove the two starter motor mounting screws. See Figure 9-20.

4. Remove the two hex. flange screws and separate the adapter plate from the crankcase. Note the orientation of the notch on the bottom, toward the dipstick. See Figure 9-21.

Figure 9-21. Removing Adapter Plate Screws.

Remove Flywheel Fan and Blocking Plates

1. Remove the four shoulder screws securing the fan to the flywheel and remove the fan. See Figure 9-22.

Figure 9-20. Removing the Starter Motor Mounting Screws.

3. Remove the starter assembly from the adapter plate.

9.6

Figure 9-22. Removing Flywheel Fan.

2. Remove the four screws securing the R.H. and L.H. blocking plates to the radiator supports and take out the plates. See Figure 9-23.

Section 9

Disassembly

Figure 9-23. Location of Four Screws Securing Blocking Plates.

Remove Overflow Reservoir

1. Remove the reservoir cap from the reservoir.

2. Loosen the two screws holding the overflow reservoir retainer bracket to the radiators. See Figure 9-24.

3. Carefully lift the bracket up slightly to unhook the locking tab, and remove the reservoir from under the bracket. See Figure 9-25.

Figure 9-25. Removing the Reservoir.

Remove Ignition Modules

1. Rotate the flywheel to position one of the tapered sections of the flywheel in line with one of the ignition modules.

2. Remove the mounting screws securing the ignition module. Access the inner screw through the hole in the main support bracket. See Figure 9-26.

Figure 9-24. Loosening Reservoir Bracket Screws.

Figure 9-26. Removing Inner Ignition Module Mounting Screw.

9.7

Section 9 Disassembly

3. Slide the ignition module onto the contoured section of the flywheel. Disconnect the lead and remove the module from the engine.

Note: On modules containing 90º terminals, the

leads must be removed by pulling to the side. See Figure 9-27.

Figure 9-27. Removing Ignition Module.

4. Repeat the procedure for the other ignition module.

Remove Flywheel

1. Use a flywheel holding tool (a suitable handle may be attached for convenience, refer to Section 2) to hold the flywheel and loosen the hex. flange screw securing the flywheel to the crankshaft. See Figure 9-28.

2. Remove the hex. flange screw and washer from the flywheel.

3. Use a puller to remove the flywheel from the crankshaft. See Figure 9-29.

Figure 9-29. Removing Flywheel.

NOTE: Always use a flywheel puller to remove

the flywheel from the crankshaft. Do not strike the crankshaft or flywheel, as these parts could become cracked or damaged.

4. Work the flywheel out from under the main bracket using the puller as a handle. See Figure 9-30.

NOTE: Always use a holding tool to hold the

flywheel when loosening or tightening the flywheel screw. Do not use any other type of bar or wedge to hold the flywheel. Use of such tools could cause the flywheel to become cracked or damaged.

Figure 9-28. Loosening Flywheel.

9.8

Figure 9-30. Removing Flywheel, Using Puller as a Handle.

5. Remove the woodruff key from the crankshaft keyway .

Remove Radiators and Cooling System

1. Remove the hex. nut from the center mounting stud, located between the two radiators and through the main support bracket. See Figure 9-31.

Figure 9-31. Removing Center Mounting Nut.

Section 9

Disassembly

Figure 9-33. Rear Bracket/Clamp.

4. Pull the by-pass hose out of the retaining clip beneath the main support bracket. See Figure 9-34.

2. Cut the metal tie strap from around the lower hose/tube assembly , secured to the blower housing. See Figure 9-32.

Figure 9-32. Cutting Tie Strap off.

3. Remove the two screws attaching the rear support bracket and half clamp to the crankcase, on the oil filter side. See Figure 9-33.

Figure 9-34. Unseating By-pass Hose.

5. Unseat the clamps and separate the hose connections at the outlet of the thermostat housing and the inlet of the water pump. See Figures 9-35, 9-36. Remove the tubular spacer from the underside of center mount, or the mounting stud in intake manifold. See step 1.

Figure 9-35. Moving Hose Clamp with Special Pliers.

9.9

Section 9 Disassembly

Figure 9-36. Lower Hose Removed.

6. Lift the entire cooling system, with the radiators, hoses, and supporting brackets attached, off the engine. See Figure 9-37. Further disassembly may be performed as required. When disassembly of hose connections is necessary , the use of a rubber lubricant on the inside of hoses will make installation easier.

Remove Stator and Rectifier-Regulator

1. Remove the two stator mounting screws. See Figure 9-38.

Figure 9-38. Removing Stator.

2. Remove the single screw securing the ground lead and rectifier-regulator. Lif t the rectifierregulator off the locating post. Work the stator leads out from under the retaining tab in the lower housing. See Figure 9-39.

Figure 9-37. Lifting the Cooling System Off.

9.10

Figure 9-39. Removing Rectifier-Regulator.

3. Unplug the connector from the rectifier-regulator. Using a small screwdriver or other narrow flat blade, bend down the locking tang on the center terminal and pull the B+ charging lead out of the connector. See Figure 9-40.

Section 9

Disassembly

Figure 9-40. Removing B+ Charging Lead from Connector.

4. Remove the stator and rectifier-regulator .

Remove Cam Pulley and Coolant Pump Belt

1. Remove the hex. flange screw and flat washer, securing the cogged drive pulley to the camshaft. See Figure 9-41.

Figure 9-42. Removing Cam Pulley and Belt.

3. Remove the camshaft key from the keyway .

Remove Water Pump and Transfer Tube

1. Unseat the clamp and disconnect the by-pass hose from the water pump fitting. See Figure 9-43.

Figure 9-43. Removing By-pass Hose from W ater Pump Fitting.

Figure 9-41. Removing Cam Pulley Mounting Hardware.

2. Lift the pulley off the camshaft and work the belt off the coolant pump pulley . See Figure 9-42.

9.11

Section 9 Disassembly

2. Loosen and unscrew the hex. cap section, securing the transfer tube to the 90° fitting in the crankcase. See Figure 9-44. Support the fitting with a wrench, if possible, when loosening the hex. cap section.

NOTE: The 90° fitting in the crankcase, which

the transfer tube is connected to, is sealed and installed at the factory in a specific position. Do not loosen, remove, or alter the mounted position of this fitting at any time. Contact the factory service department for specific instructions if the fitting is damaged, or its mounting is affected in any way .

4. Lift the pump up and carefully work the ferruled end of the transfer tube out of the fitting. Remove the water pump with the tube and the hose section attached. Remove the O-Ring from within the channel. See Figure 9-46.

Figure 9-46. Lifting Out W ater Pump and Transfer Tube.

5. If required, remove the hose clamps, noting size differences and installed positions with respect to the tangs. This is critical for clearance to the blower housing. Separate the transfer tube, and hose section from the water pump.

Figure 9-44. Removing Hex. Cap Section.

3. Remove the six screws securing the water pump to the crankcase. See Figure 9-45.

Figure 9-45. Removing the Six Water Pump Screws.

Remove By-pass Hose and Wiring Harness

1. Unseat the clamp and disconnect the coolant bypass hose from the fitting on the intake manifold. See Figure 9-47.

Figure 9-47. Removing Coolant By-pass Hose from Intake Manifold Fitting.

9.12

2. Remove the two No. 1 side intake manifold mounting screws securing the ground leads and clip for the wiring harness. Note the locations of the clip and ground leads. See Figure 9-48.

Figure 9-48. Removing No. 1 Side Intake Manifold Screws with the Ground Leads.

Section 9

Disassembly

Figure 9-50. Warning Alarm.

4. Lift the by-pass hose, with the wiring harness attached, and work the ends of the harness back through the openings in the lower blower housing to remove. See Figure 9-51.

3. Disconnect the wire leads from the Oil Sentry and safety interlock switch, temperature sensor, and/or warning alarm, as equipped. See Figures 9-49 and 9-50.

Figure 9-49. T emperature Sensor.

™

Figure 9-51. Removing By-pass Hose and Wiring Harness.

9.13

Section 9 Disassembly

Remove Intake Manifold, Temperature Sensor, and Thermostat

1. Remove the four remaining hex. flange screws securing the intake manifold to the cylinder heads. See Figure 9-52.

Figure 9-52. Removing Remaining Intake Manifold Screws.

2. Separate the intake manifold from the cylinder heads and remove it, by shifting it toward the crankshaft, until the carburetor studs clear the lower blower housing. Remove the intake manifold gaskets. See Figure 9-53.

Remove Lower Blower Housing and Oil Fill/Dipstick Tube

1. Remove the breather hose from the No. 1 side valve cover fitting.

2. Remove the eight hex. flange thread forming screws securing the lower blower housing to the crankcase. Note the location of the lifting bracket attached to the blower housing mounting screw on the No. 2 side. See Figure 9-54.

Lifting Bracket

Figure 9-54. Removing the Eight Lower Blower Housing Mounting Screws and Lifting Bracket.

3. Lift the lower blower housing up and separate the oil fill/dipstick tube from the notch. Remove the blower housing. See Figure 9-55.

Figure 9-53. Removing Intake Manifold and Gaskets.

3. If the thermostat is to be removed, loosen and remove the two hex. flange screws securing the thermostat housing to the intake manifold. Separate the housing and remove the thermostat and the old gasket.

9.14

Figure 9-55. Removing Lower Blower Housing.

4. Clean the crankcase area around the dipstick tube of all dirt and debris. Carefully pull upwards on the tube assembly to unseat and remove it. See Figure 9-56.

Figure 9-56. Removing Dipstick Tube Assembly.

Remove Oil Sentry™ (If So Equipped)

1. Remove the Oil Sentry™ switch, from the breather cover. See Figure 9-57.

Section 9

Disassembly

2. Carefully pry under the protruding edge of the breather cover with a screwdriver to separate the cover. See Figure 9-59. Do not pry on the sealing surfaces as it could cause damage resulting in leaks.

Figure 9-59. Prying Off Breather Cover.

Figure 9-57. Removing Oil Sentry™ Switch.

Remove Breather Cover

1. Remove the four hex. flange screws securing the breather cover to the crankcase. See Figure 9-58.

3. Remove the cover and the gasket. See Figure 9-60.

Figure 9-60. Removing Breather Cover and Gasket.

Figure 9-58. Removing Breather Cover Screws.

9.15

Section 9 Disassembly

Remove Spark Plugs

1. Remove the spark plug from each cylinder head using a spark plug socket. See Figure 9-61.

Figure 9-61. Removing Spark Plug(s).

Remove Valve Covers

1. Remove the four hex. flange screws securing each of the valve covers. Note the differences between the covers, and the lengths of the screws, for proper installation later . See Figure 9-62.

Figure 9-63. Removing the Valve Cover.

Remove Cylinder Heads and Hydraulic Lifters

1. Rotate the crankshaft until the valves of one of the cylinders are closed. Loosen the rocker arm screws until the rocker arms can be pivoted to free the push rods.

2. Remove and mark the location of the push rods (intake or exhaust) and the respective cylinder (1 or 2). The push rods should always be reinstalled in their original locations. See Figure 9-64.

Figure 9-62. Removing Valve Cover Screws.

2. Break the cover/gasket seal by carefully prying under the edges of the cover. Remove the cover and gasket from each side. See Figure 9-63.

9.16

Figure 9-64. Removing Push Rods.

3. Repeat for the opposite cylinder.

4. Remove the four hex. flange nuts and washers from the studs securing each cylinder head. See Figure 9-65.

Section 9

Disassembly

Figure 9-65. Removing Hex. Flange Nuts and Washers from Studs.

5. Carefully remove the cylinder heads, and head gaskets. See Figure 9-66.

NOTE: It is not necessary to remove the cylinder

studs from the crankcase unless replacement is intended. If studs are removed for any reason, discard the old stud(s), do not reuse/reinstall. Use new studs and refer to the assembly sequence for proper installation.

Figure 9-67. Removing Lifters from Lifter Bores.

Disassemble Cylinder Heads

1. Remove the two hex. flange screws, shims, rocker arms and pivots from one of the cylinder heads. See Figure 9-68.

Figure 9-68. Removing Rocker Arms and Pivots.

2. Compress the valve springs using a valve spring compressor and remove the valve spring keepers. See Figure 9-69.

Figure 9-66. Removing Cylinder Heads and Gaskets.

6. Remove and mark the hydraulic lifters corresponding to location (intake or exhaust) and the respective cylinder (1 or 2). Hydraulic lifters should always be reinstalled in their original locations. See Figure 9-67.

Figure 9-69. Compressing Valve S pring.

9.17

Section 9 Disassembly

3. With the keepers taken out, the following items can be removed (see Figures 9-70 and 9-71):

• valve spring retainers

• valve springs

• valve spring caps

• intake and exhaust valves

• valve stem seals (intake valve only)

NOTE: These engines use a valve stem seal on

the intake valves. Always use a new seal when the valves are removed from the cylinder head. Replace the seals if they are deteriorated or damaged in any way . Never reuse an old seal.

Remove Oil Pan Assembly

1. Remove the ten hex. flange screws securing the oil pan to the crankcase. See Figure 9-72. Note the location of the silver plated (grounding) hex. flange screw, to the right of the oil filter boss.

Figure 9-72. Removing Oil Pan Fasteners.

2. Locate the splitting tab cast into the perimeter of the oil pan. Insert the drive end of a breaker bar between the splitting tab and the crankcase, and turn it to break the RTV seal. See Figure 9-73. Do not pry on the sealing surfaces as this can cause leaks.

Figure 9-70. Valve Component s.

Figure 9-71. Removing Intake V alve Seal.

4. Repeat the above procedure for the other cylinder head. Do not interchange parts from one cylinder head with parts from the other cylinder head.

3. Remove the oil pan from the crankcase.

Figure 9-73. Splitting Oil Pan from Crankcase.

Governor Assembly (Internal)

The governor gear assembly is located inside the oil pan. If service is required, refer to the service procedures under ‘‘Governor Assembly’’ in Section 10.

9.18

Section 9

Disassembly

Oil Pump Assembly

The oil pump is mounted in the oil pan. If service is required, refer to the service procedures under ‘‘Oil Pump Assembly’ ’ in Section 10.

Remove Camshaft

1. Remove the camshaft and shim. See Figure 9-74.

Figure 9-74. Removing Camshaft and Shim.

Remove Governor Cross Shaft

1. Remove the retaining ring and nylon washer from the governor cross shaft. See Figure 9-75.

NOTE: Always use a new retaining ring when

reassembling. Do not reuse the old retaining ring.

2. Remove the cross shaft through the inside of the crankcase. Be careful not to lose the small washer on the lower portion of the shaft, just above the stake marks. See Figure 9-76.

Figure 9-76. Removing Governor Cross Shaft.

Remove Connecting Rods with Pistons and Rings

1. Remove the two hex. flange screws securing the closest connecting rod end cap. Remove the end cap. See Figure 9-77.

NOTE: If a carbon ridge exists at the top of

either cylinder bore, use a ridge reamer to remove it before attempting to remove the piston.

Figure 9-75. Removing Retaining Ring and Nylon Washer.

Figure 9-77. Removing Connecting Rod End Cap.

9.19

Section 9 Disassembly

2. Carefully remove the connecting rod and piston assembly from the cylinder bore. See Figure 9-78.

NOTE: The cylinders are numbered on the

crankcase. Use the numbers to mark each end cap, connecting rod, and piston for reassembly . Do not mix end cap s and connecting rods.

Figure 9-78. Removing Connecting Rod and Piston Assembly .

Remove Crankshaft

1. Carefully pull the crankshaft out of the crankcase. See Figure 9-79.

Figure 9-79. Removing Crankshaft.

3. Repeat the above procedure for the other connecting rod and piston assembly .

9.20

Section 10

Go Back

Inspection and Reconditioning

LV560, LV625, LV675

Section 10

Inspection and Reconditioning

This section covers the operation, inspection, and repair/reconditioning of major internal engine components. The following components are not covered in this section. They are covered in sections of their own:

Air Cleaner, Section 4 Carburetor & External Governor, Section 5 Ignition, Charging & Electric Starter, Section 8

Clean all parts thoroughly. Only clean parts can be accurately inspected and gauged for wear or damage. There are many commercially available cleaners that will quickly remove grease, oil, and grime from engine parts. When such a cleaner is used, follow the manufacturer’s instructions and safety precautions carefully. Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation. Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil.

Use an aerosol gasket remover or paint remover to remove the old RTV from the crankcase and oil pan. Apply the solvent, give it time to work (5-10 minutes), and then brush the treated surface with a brass wire brush to remove the softened RTV. Do not scrape the surfaces when cleaning as this will damage the surfaces and could result in leaks.

Refer to ‘‘A Guide to Engine Rebuilding’ ’ (TP-2150) for additional information. ‘ ‘Measurement Guide’’ (TP-2159-A) and ‘‘Engine Inspection Data Record’’ (TP-2435) are also available; use these to record inspection result s.

Camshaft and Crankshaft

Inspection and Service

Inspect the gear teeth of the camshaft and crankshaft. If the teeth are badly worn, chipped, or some are missing, replacement will be necessary . If there is tooth damage on either the camshaft gear or crankshaft gear, both the camshaf t and crankshaf t must be replaced.

Inspect the bearing surfaces for scoring, grooving, etc. Measure the running clearance between the bearing journals and their respective bores. Use an inside micrometer or telescoping gauge to measure the

inside diameter of both bearing bores in the vertical and horizontal planes. Use an outside micrometer to measure the outside diameter of the bearing journals. Subtract the journal diameters from their respective bore diameters to get the running clearances. Check the results against the specifications in Section 1. If the running clearances are within specification, and there is no evidence of scoring, grooving, etc., no further reconditioning is necessary . If the bearing surfaces are worn or damaged, the crankcase and/or oil pan will need to be replaced.

Inspect the crankshaft keyways. If worn or chipped, replacement of the crankshaft will be necessary .

10.1

Section 10

Inspection and Reconditioning

Inspect the crankpin for score marks or metallic pick up. Slight score marks can be cleaned with crocus cloth soaked in oil. If wear limits, as stated in “Specifications and Tolerances,” are exceeded, it will be necessary to either replace the crankshaft or regrind the crankpin to 0.25 mm (0.010 in.) undersize. If reground, 0.25 mm (0.010 in.) undersize connecting rods (big end) must then be used to achieve proper running clearance. Measure the crankpin for size, taper , and out-of-round.

NOTE: If the crankpin is reground, visually check to

ensure that the fillet blends smoothly with the crankpin surface. See Figure 10-1.

High Point From Fillet Intersections

The Fillet Must Blend Smoothly With The Bearing Journal Surface

45°

Minimum

Use the following procedure to remove and replace the plug.

Procedure to Remove Crankshaft Plug:

1. Drill a 3/16" hole through the plug in the crankshaft.

2. Thread a 3/4" or 1" long self-tapping screw with a flat washer into the drilled hole. The flat washer must be large enough to seat against the shoulder of the plug bore. See Figure 10-2.

Self-T apping Screw

Flat Washer

234567

Plug

Crankshaft

This Fillet Area Must Be Completely Smooth

Figure 10-1. Crankpin Fillets.

When grinding a crankshaft, grinding stone deposits can get caught in oil passages which could cause severe engine damage. Removing the crankpin plug each time the crankshaft is ground provides easy access for cleaning any grinding deposits that may collect in the oil passages.

Figure 10-2. Removing Crankpin Plug.

3. Tighten the self-tapping screw until it draws the plug out of the crankshaft.

Procedure to Install New Plug:

1. Use a single cylinder camshaft pin Kohler Part No. 47 380 09-S as a driver and tap the plug into the plug bore until it seats at the bottom of the bore. Make sure the plug is tapped in evenly to prevent leakage.

10.2

Section 10

Inspection and Reconditioning

Crankcase

These engines contain a cast-iron cylinder liner that may be reconditioned as follows:

Inspection and Service

Check all gasket surfaces to make sure they are free of gasket fragments. Gasket surfaces must also be free of deep scratches or nicks.

Check the cylinder bore for scoring. In severe cases, unburned fuel can cause scuffing and scoring of the cylinder wall. It washes the necessary lubricating oils off the piston and cylinder wall. As raw fuel seeps down the cylinder wall, the piston rings make metal to metal contact with the wall. Scoring of the cylinder wall can also be caused by localized hot spots resulting from a cooling system problem or from inadequate or contaminated lubrication.

If the cylinder bore is badly scored, excessively worn, tapered, or out-of-round, resizing is necessary . Use an inside micrometer to determine amount of wear (refer to the “Specifications, Tolerances, and Special Torque V alues”, in Section 1), then select the nearest suitable oversize of either 0.08 mm (0.003 in.), 0.25 mm (0.010 in.), or 0.50 mm (0.020 in.). Resizing to one of these oversizes will allow usage of the available oversize piston and ring assemblies. Initially , resize using a boring bar, then use the following procedures for honing the cylinder.

2. With the lower edge of each stone positioned even with the lowest edge of the bore, start drill and honing process. Move the hone up and down while resizing to prevent the formation of cutting ridges. Check the size frequently .

3. When the bore is within 0.064 mm (0.0025 in.) of desired size, remove the coarse stones and replace with burnishing stones. Continue with the burnishing stones until within 0.013 mm (0.0005 in.) of desired size and then use finish stones (220-280 grit) and polish to final size. A crosshatch should be observed if honing is done correctly . The crosshatch should intersect at approximately 23-33° off the horizontal. Too flat an angle could cause the rings to skip and wear excessively , too steep an angle will result in high oil consumption. See Figure 10-3.

NOTE: If the bore is beyond the wear limit, a new

miniblock or short block will be required.

Honing

While most commercially available cylinder hones can be used with either portable drills or drill presses, the use of a low speed drill press is preferred as it facilitates more accurate alignment of the bore in relation to the crankshaft crossbore. Honing is best accomplished at a drill speed of about 250 RPM and 60 strokes per minute. After inst alling coarse stones in hone, proceed as follows:

1. Lower hone into bore and after centering, adjust so that the stones are in contact with the cylinder wall. Use of a commercial cutting-cooling agent is recommended.

Figure 10-3. Cylinder Bore Crosshatch After Honing.

4. After resizing, check the bore for roundness, taper, and size. Use an inside micrometer, telescoping gauge, or bore gauge to take measurements. The measurements should be taken at three locations in the cylinder-at the top, middle, and bottom. T wo measurements should be taken (perpendicular to each other) at each of the three locations.

10.3

Section 10 Inspection and Reconditioning

Clean Cylinder Bore After Honing

Proper cleaning of the cylinder walls following boring and/or honing is very critical to a successful overhaul. Machining grit left in the cylinder bore can destroy an engine in less than one hour of operation after a rebuild.

The final cleaning operation should always be a thorough scrubbing with a brush and hot, soapy water. Use a strong detergent that is capable of breaking down the machining oil while maintaining a good level of suds. If the suds break down during cleaning, discard the dirty water and start again with more hot water and detergent. Following the scrubbing, rinse the cylinder with very hot, clear water, dry it completely, and apply a light coating of engine oil to prevent rusting.

Measuring Piston-to-Bore Clearance

Before installing the piston into the cylinder bore, it is necessary that the clearance be accurately checked. This step is often overlooked, and if the clearances are not within specifications, engine failure will usually result.

2. Use an inside micrometer, telescoping gauge, or bore gauge and measure the cylinder bore. Take the measurement approximately 63.5 mm (2.5 in.) below the top of the bore and perpendicular to the piston pin.

3. Piston-to-bore clearance is the difference between the bore diameter and the piston diameter (step 2 minus step 1).

Flywheel

Inspection

Inspect the flywheel for cracks, and the flywheel keyway for damage. Replace flywheel if cracked. Replace the flywheel, the crankshaft, and the key if flywheel key is sheared or the keyway is damaged.

Inspect the ring gear for cracks or damage. Kohler does not provide ring gears as a serviceable part. Replace the flywheel if the ring gear is damaged.

Check the charging system magnets to be sure they are not loose or cracked.

NOTE: Do not use a feeler gauge to measure piston-

to-bore clearance–it will yield inaccurate measurements. Always use a micrometer.

Use the following procedure to accurately measure the piston-to-bore clearance:

1. Use a micrometer and measure the diameter of the piston 6 mm (0.24 in.) above the bottom of the piston skirt and perpendicular to the piston pin. See Figure 10-4.

6 mm (0.24 in.)

Measure 6 mm Above the Bottom of Piston Skirt at Right Angels to Piston Pin.

Cylinder Head and Valves

Inspection and Service

Carefully inspect the valve mechanism parts. Inspect the valve springs and related hardware for excessive wear or distortion. Check the valves and valve seat area or inserts for evidence of deep pitting, cracks, or distortion. Check clearance of the valve stems in guides. See Figure 10-5 for valve details and specifications.

Hard starting, or loss of power accompanied by high fuel consumption may be symptoms of faulty valves. Although these symptoms could also be attributed to worn rings, remove and check the valves first. Af ter removal, clean the valve heads, faces, and stems with a power wire brush. Then, carefully inspect each valve for defects such as warped head, excessive corrosion, or worn stem end. Replace valves found to be in bad condition. A normal valve and valves in bad condition are shown in the accompanying illustrations.

Figure 10-4. Measuring Piston Diameter.

10.4

Section 10

Inspection and Reconditioning

Exhaust Valve

A B C D E F G H

Figure 10-5. Valve Det ails.

Seat Angle Insert O.D. Guide Depth Guide I.D. V alve Head Diameter V alve Face Angle V alve Margin (Min.) V alve Stem Diameter

Dimension

Intake V alve

89°

36.987/37.013 mm 4 mm

7.038/7.058 mm

33.37/33.63 mm 45°

1.5 mm

6.982/7.000 mm

Exhaust

Insert

Intake Insert

Intake Exhaust

89°

32.987/33.013 mm

6.5 mm

7.038/7.058 mm

29.37/29.63 mm 45°

1.5 mm

6.970/6.988 mm

Normal: Even after long hours of operation a valve can be reconditioned and reused if the face and margin are in good shape. If a valve is worn to where the margin is less than 1/32" do not reuse it. The valve shown was in operation for almost 1000 hours under controlled test conditions.

Bad Condition: The valve depicted here should be

replaced. Note the warped head; margin damaged and too narrow. These conditions could be attributed to excessive hours or a combination of poor operating conditions.

10.5

Section 10 Inspection and Reconditioning

Leakage: A poor grind on face or seat of valve will allow

leakage resulting in a burned valve on one side only .

Stem Corrosion: Moisture in fuel or from condensation are the most common causes of valve stem corrosion. Condensation occurs from improper preservation during storage and when engine is repeatedly stopped before it has a chance to reach normal operating temperatures. Replace corroded valves.

Gum: Gum deposits usually result from using stale gasoline. Gum is a prevalent cause of valve sticking. The cure is to ream the valve guides and clean or replace the valves, depending on their condition.

Coking: Coking is normal on intake valves and is not harmful. If the seat is good, the valve could be reused after cleaning.

Excessive Combustion T emperatures: The white deposits seen here indicate very high combustion temperatures, usually due to a lean fuel mixture.

10.6

Overheating: An exhaust valve subject to overheating

will have a dark discoloration in the area above the valve guide. Worn guides and faulty valve springs may cause this condition. Also check for clogged air int ake, and blocked fins when this condition is noted.

Valve Guides

If a valve guide is worn beyond specifications, it will not guide the valve in a straight line. This may result in burnt valve faces or seats, loss of compression, and excessive oil consumption.

To check valve guide-to-valve stem clearance, thoroughly clean the valve guide and, using a split-ball gauge, measure the inside diameter. Then, using an outside micrometer , measure the diameter of the valve stem at several points on the stem where it moves in the valve guide. Use the largest stem diameter to calculate the clearance. If the intake clearance exceeds 0.038/0.076 mm (0.0015/0.003 in.) or the

exhaust clearance exceeds 0.050/0.088 mm (0.0020/0.0035 in.), determine whether the valve stem

or guide is responsible for the excessive clearance. Maximum (I.D.) wear on the intake valve guide is

7.134 mm (0.2809 in.) while 7.159 mm (0.2819 in.) is the maximum allowed on the exhaust guide. The guides are not removable but can be reamed 0.25 mm

(0.010 in.) oversize with Tool No. KO1026. Valves with

0.25 mm oversize stems must then be used.

If the guides are within limits but the valve stems are worn beyond limits, replace with new valves.

Section 10

Inspection and Reconditioning

Valve Seat Cutter

Pilot

Figure 10-6. T ypical Valve Seat Cutter.

Lapping Valves

Reground or new valves must be lapped in, to provide fit. Use a hand valve grinder with suction cup for final lapping. Lightly coat valve face with “fine” grade of grinding compound, then rotate valve on seat with grinder. Continue grinding until smooth surface is obtained on seat and on valve face. Thoroughly clean cylinder head in soap and hot water to remove all traces of grinding compound. After drying cylinder head, apply a light coating of SAE 10 oil to prevent rusting.

Valve Seat Insert s

Hardened steel alloy intake and exhaust valve seat inserts are press fitted into the cylinder head. The inserts are not replaceable on the engines but can be reconditioned if not too badly pitted or distorted. If cracked or badly warped, the cylinder head should be replaced.

Recondition the valve seat inserts following the instructions provided with the valve seat cutter being used. A typical cutter is shown in Figure 10-6. The final cut should be made with an 89° cutter as specified for the valve seat angle in Figure 10-5. With the proper 45° valve face angle as specified in Figure 10-5 and the valve seat cut properly (44.5° as measured from centerline when cut 89°) this would result in the desired 0.5° (1.0° full cut) interference angle where the maximum pressure occurs on the outside diameters of valve face and seat.

Intake V alve S tem Seal

These engines use valve stem seals on the intake valves. Always use a new seal when valves are removed from cylinder head. The seals should also be replaced if deteriorated or damaged in any way . Never

reuse an old seal.

10.7

Section 10 Inspection and Reconditioning

Pistons and Rings

Inspection

Scuffing and scoring of pistons and cylinder walls occurs when internal temperatures approach the welding point of the piston. Temperatures high enough to do this are created by friction, which is usually attributed to improper lubrication, and/or overheating of the engine.

Normally , very little wear takes place in the piston boss-piston pin area. If the original piston and connecting rod can be reused after new rings are installed, the original pin can also be reused but new piston pin retainers are required. The piston pin is included as part of the piston assembly. If the pin bosses or the pin, are worn or damaged, a new piston assembly is required.

Ring failure is usually indicated by excessive oil consumption and blue exhaust smoke. When rings fail, oil is allowed to enter the combustion chamber where it is burned along with the fuel. High oil consumption can also occur when the piston ring

end gap is incorrect, because the ring cannot properly conform to the cylinder wall. Oil control is also lost when ring gaps are not staggered during installation.

When cylinder temperatures get too high, lacquer and varnish collect on pistons causing rings to stick which results in rapid wear . A worn ring usually t akes on a shiny or bright appearance.

Scratches on rings and pistons are caused by abrasive material such as carbon, dirt, or pieces of hard metal. Detonation damage occurs when a portion of the fuel charge ignites spontaneously from heat and pressure shortly after ignition. This creates two flame fronts which meet and explode to create extreme hammering pressures on a specific area of the piston. Detonation generally occurs from using low octane fuels.

Preignition or ignition of the fuel charge before the timed spark can cause damage similar to detonation. Preignition damage is often more severe than detonation damage. Preignition is caused by a hot spot in the combustion chamber from sources such as glowing carbon deposits, improperly seated valve, or wrong spark plug. See Figure 10-7 for some common types of piston and ring damage.

Overheated or Deteriorated Oil

Figure 10-7. Common T ypes of Piston and Ring Damage.

10.8

Abrasive Scratched RingsStuck, Broken Rings

Scored Piston and Rings

Kohler 1500, TP-2509, LV560, 05810334 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual