Service manual

ENGINE TROUBLESHOOTING
PROBLEM
PROBABLE CAUSE VERIFICATION/REMEDY
SMOKY EXHAUST (cont.)
WHITISH OR PURPLISH (cont.)
d. Worn valve stem and valve guide. d. Replace.
e. Low engine oil viscosity. e. Replace.
f. Excessive oil pressure.
f. Correct.
3. Injection timing is too late.
3. Adjust.
4. Insufficient compression. 4. See LOW COMPRESSION; HARD STARTING.
BLACKISH OR DARK GRAYISH
1. Engine body troubles.
a. Poor compression.
a. See LOW COMPRESSION; HARD STARTING.
b. Improper valve clearance. b. Adjust.
2. Insufficient intake air (air cleaner clogged).
2. Clean air cleaner.
3. Improper fuel.
3. Replace with proper fuel.
ABNORMAL SOUND
CRANKSHAFT AND MAIN BEARING
OR NOISE
1. Badly worn bearing.
1. Replace bearing and grind crankshaft.
2. Badly worn crankshaft.
2. Grind crankshaft.
3. Melted bearing.
3. Replace bearing and check lubrication system.
CONNECTING ROD AND CONNECTING ROD BEARING
1. Worn connecting rod big end bearing.
1. Replace bearing.
2. Worn crankpin.
2. Grind crankshaft.
3. Bent connecting rod.
3. Correct bend or replace.
PISTON, PISTON PIN, AND PISTON RING
1. Worn cylinder.
1. Rebore cylinder to oversize and replace piston.
2. Worn piston pin.
2. Replace piston.
3. Piston seized.
3. Replace piston and rebore cylinder.
4. Piston seized and ring wom or damaged.
4. Replace piston and rings.
VALVE MECHANISM
1. Worn camshaft.
1. Replace.
2. Excessive valve clearance. 2. Adjust.
3. Worn timing gear.
3. Replace.
4. Worn fan pulley bearing.
4. Replace.
ROUGH OPERATION
INJECTION PUMP SYSTEM
1. Uneven injection.
1. Adjust injection or replace parts.
2. Control rack malfunctioning.
2. Disassemble, check and correct injection pump.
3. Worn delivery valve.
3. Replace.
4. Inadequate injection nozzle spray.
4. Replace injection nozzle.
GOVERNING SYSTEM
1. Governor lever malfunctioning.
1. Check governor shaft and correct operation.
2. Fatigued governor spring.
2. Replace.
(continued)
Engines & Generators
6