Engine Lacks Power - Honda GL1800 Service Manual

ENGINE LACKS POWER

1. Drive Train Inspection
Raise wheel off the ground and spin by hand.
Does the wheel spin freely?
NO
YES
2. Tire Pressure Inspection
Check the tire pressure.
Are the tire pressures correct?
NO
YES
3. Clutch Inspection
Accelerate rapidly low to second.
Does the engine speed change accordingly when clutch is released?
NO
YES
4. Engine Performance Inspection
Accelerate lightly.
Does the engine speed increase?
NO
YES
5. Spark Plug Inspection
Remove and inspect spark plugs.
Are the spark plugs in good condition?
NO
YES
6. Engine Oil Inspection
Check the oil level and condition.
Is the engine oil in good condition?
NO
YES
7. Ignition Timing Inspection
Check the ignition timing.
Is the ignition timing as specified?
NO
YES
– • Brake dragging
• Worn or damaged final gear bearings
– GO TO STEP 2.
– • Faulty tire valve
• Punctured tire
– GO TO STEP 3.
– • Clutch slipping
• Worn clutch discs/plates
• Warped clutch discs/plates
• Weak clutch spring
• Faulty hydraulic assist system
• Additive in engine oil
– GO TO STEP 4.
– • Clogged air cleaner
• Restricted fuel flow
• Clogged muffler
– GO TO STEP 5.
– • Plugs not serviced frequently enough
• Incorrect spark plug heat range
– GO TO STEP 6.
– • Oil level too high
• Oil level too low
• Contaminated oil
– GO TO STEP 7.
– • Faulty engine control module (ECM)
• Faulty ignition pulse generator
– GO TO STEP 8.
TROUBLESHOOTING
25-3