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

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

Go Back

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

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