23
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
excessive
3.
Tooth contact
improper
4.
Bearing
damaged
5.
Gears
worn - chipped
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
out of adjustment
2.
Valve seating
poor
3.
Valve guides
defective
4.
Rocker arms - arm shaft
worn
5.
Magneto
defective
6.
ECU
defective
7.
Spark plug
fouled - gap too wide
8.
Ignition coil
defective
9.
Idle Step Control (ISC)
malfunction
1. Adjust clearance
2. Replace - service seats - valves
3. Replace cylinder head
4. Replace arms - shafts
5. Replace stator coil
6. Replace ECU
7. Adjust gap - replace plug
8. Replace ignition coil
9. Replace ISC
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.
Cam - rocker arms - tappets
worn
5.
Spark plug gap
too narrow
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. Correct timing - check chain, sprockets, and cam chain ten-
stioner
4. Replace cam - arms - tappets
5. Adjust gap
6. Replace ignition coil
7. Replace fuel pump
8. Clean element
9. Clean or replace hose
Problem: Exhaust smoke dirty or heavy
Condition
Remedy
1.
Oil (in the engine)
overfilled - contaminated
2.
Piston rings - cylinder
worn
3.
Valve guides
worn
4.
Cylinder wall
scored - scuffed
5.
Valve stems
worn
6.
Stem seals
defective
1. Drain excess oil - replace oil
2. Replace - service rings - cylinder
3. Replace cylinder head
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.
Air cleaner element
obstructed
10.
Oil (in the engine)
overfilled - contaminated
11.
Intake manifold
leaking air
12.
Cam chain
worn
1. Adjust clearance
2. Replace springs
3. Re-time valve gear
4. Replace - service rings - cylinder
5. Replace cylinder head/valves
6. Clean - replace plug
7. Replace arms - shafts
8. Adjust gap - replace plug
9. Clean element
10. Drain excess oil - change oil
11. Tighten - replace manifold
12. Replace cam chain
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
7.
Intake manifold
leaking air
8.
Fan
malfunctioning
9.
Fan switch
malfunctioning
10.
Radiator fus
obstructed
11.
Coolant
level low
12.
Thermostat
sticking
1. Clean piston
2. Add oil
3. Drain - replace gasoline
4. Replace pump
5. Clean circuit
7. Tighten - replace manifold
8. Check fan fuse - replace fan
9. Replace fan switch
10. Clean radiator
11. Add coolant
12. Replace thermostat
Manual
Table of Contents
