42
Problem: Engine noisy (Noise seems to come from secondary bevel gear and final driven shaft)
Condition
Remedy
1.
Drive - driven bevel gears
damaged - worn
2.
Backlash
incorrect
3.
Tooth contact
improper
4.
Bearing
damaged
5.
Gears
worn
6.
Splines
worn
1. Replace gears
2. Adjust backlash
3. Adjust contact
4. Replace bearing
5. Replace gears
6. Replace shaft(s)
Problem: Engine idles poorly
Condition
Remedy
1.
Valve clearance
incorrect
2.
Valve seating
poor
3.
Valve guides
defective
4.
Rocker arms - arm shaft
worn
5.
Magneto
defective
6.
ECM
defective
7.
Spark plug
fouled - gap incorrect
8.
Ignition coil
defective
9.
Fuel injector
obstructed
1. Adjust clearance
2. Replace - service seats - valves
3. Replace guides
4. Replace arms - shafts
5. Replace stator coil
6. Replace ECM
7. Adjust gap - replace plug
8. Replace ignition coil
9. Replace fuel injector
Problem: Engine runs poorly at high speed
Condition
Remedy
1.
High RPM “cut out”
against RPM limiter
2.
Valve springs
weak
3.
Valve timing
incorrect
4.
Cams - rocker arms - tappets
worn
5.
Spark plug gap
incorrect
6.
Ignition coil
defective
7.
Fuel pump
defective
8.
Air cleaner element
obstructed
9.
Fuel hose
obstructed
1. Shift into higher gear - decrease speed
2. Replace springs
3. Time valves
4. Replace cams - arms - tappets
5. Adjust gap
6. Replace ignition oil
7. Replace fuel pump
8. Clean element
9. Clean or replace hose
Problem: Exhaust smoke dirty or heavy
Condition
Remedy
1.
Engine oil
overfilled - contaminated
2.
Piston rings - cylinder
worn
3.
Valve guides
worn
4.
Cylinder wall
scored
5.
Valve stems
worn
6.
Stem seals
defective
1. Drain excess oil - replace oil
2. Replace - service rings - cylinder
3. Replace guides
4. Replace - service cylinder
5. Replace valves
6. Replace seals
Problem: Engine lacks power
Condition
Remedy
1.
Valve clearance
incorrect
2.
Valve springs
weak
3.
Valve timing
incorrect
4.
Piston ring(s) - cylinder
worn
5.
Valve seating
poor
6.
Spark plug
fouled
7.
Rocker arms - shafts
worn
8.
Spark plug gap
incorrect
9.
Fuel injector
obstructed
10.
Cam chain
worn
11.
Air cleaner element
obstructed
12.
Engine oil
overfilled - contaminated
13.
Intake manifold
leaking air
1. Adjust clearance
2. Replace springs
3. Re-time valve gear
4. Replace - service rings - cylinder
5. Repair seats
6. Clean - replace plug
7. Replace arms - shafts
8. Adjust gap - replace plug
9. Replace injector
10. Replace cam chain
11. Clean element
12. Drain excess oil - change oil
13. Tighten - replace manifold
Problem: Engine overheats
Condition
Remedy
1.
Carbon deposit (piston crown)
excessive
2.
Oil
low
3.
Octane
low - gasoline poor
4.
Oil pump
defective
5.
Oil circuit
obstructed
6.
Intake manifold
leaking air
7.
Fan
malfunctioning
8.
Fan relay
malfunctioning
9.
Radiator hoses - cap
damaged - obstructed
10.
Coolant level
low
11.
Thermostat
stuck - closed
1. Clean piston
2. Add oil
3. Drain - replace gasoline
4. Replace pump
5. Clean circuit
6. Tighten - replace manifold
7. Replace fan relay
8. Check fan fuse - replace fan
9. Clear obstruction - replace hoses
10. Fill - examine system for leaks
11. Replace thermostat