5. If the spark is good, check the following:
a. Try starting the engine by following normal
starting procedures. If the engine does not
start, go to Step 6.
b. If the engine starts but then stops, check for
an inoperative choke, incorrect carburetor ad-
justment, leaking intake manifolds, improper
ignition timing or contaminated fuel.
6. If the engine turns over but does not start, the en-
gine compression is probably low. Check for the
following possible malfunctions:
a. Leaking cylinder head gasket.
b. Valve clearance too tight.
c. Bent or stuck valve.
d. Incorrect valve timing.
e. Improper valve-to-seat contact.
f. Worn cylinders and/or piston rings.
Engine Does Not Crank
If the engine will not turn over, check for one or
more of the following:
1. Blown fuse.
2. Discharged battery.
3. Defective starter, starter relay, starting circuit
cutoff switch, or starter switch.
4. Faulty starter clutch.
5. Seized pistons(s).
6. Seized crankshaft bearings.
7. Broken connecting rod.
8. Locked-up transmission or clutch assembly.
9. Defective starter clutch.
ENGINE PERFORMANCE
In the following checklists, it is assumed that
the engine runs, but is not operating at peak per-
formance. This section serves as a starting point
from which to isolate a performance problem.
Where ignition timing is mentioned as a problem,
remember that the ignition timing cannot be ad-
justed. If the ignition timing is incorrect, a part
within the ignition system is faulty. Check the in-
dividual ignition system components, and replace
any faulty part.
Engine Will Not Idle
1. Carburetors not synchronized.
2. Incorrect idle speed adjustment.
3. Fouled or improperly gapped spark plug(s).
4. Leaking head gasket(s) or vacuum leak.
5. Incorrect valve clearance or valve timing.
6. Obstructed fuel line or fuel valve.
7. Low engine compression.
8. Starter valve (choke) stuck in the open position.
9. Incorrect pilot screw adjustment.
10. Clogged pilot jet or pilot air jet.
11. Clogged air filter element.
12. Faulty fuel pump.
13. Incorrect throttle cable free play.
14. Faulty ignition system component.
Low or Poor Engine Power
1. Securely support the motorcycle with the rear
wheel off the ground, and spin the rear wheel by
hand. If the wheel spins freely, perform Step 2. If
the wheel does not spin freely, check for the follow-
ing conditions:
a. Dragging rear brake.
b. Excessive rear axle torque.
c. Worn or damaged rear wheel bearings.
d. Worn or damaged final gear bearings.
2. Check the tire pressure. If pressure is normal,
perform Step 3. If pressure is low, the tire valve is
faulty.
3. Ride the motorcycle, and accelerate rapidly from
first to second gear. If the engine speed reduces
when the clutch is released, perform Step 4. If the
engine speed does not change when the clutch is re-
leased, check for the following:
a. Slipping clutch.
b. Worn or warped clutch plates or friction
discs.
c. Weak clutch spring.
d. Incorrect clutch cable free play.
e. Check the engine oil for additives.
4. Ride the motorcycle and accelerate lightly. If the
engine speed increases relative to throttle operation,
perform Step 5. If engine speed does not increase,
check for the following:
a. Choke valve opened.
b. Clogged air cleaner.
c. Fuel flow restricted.
d. Clogged muffler.
e. Faulty fuel pump.
f. Faulty starting circuit cutoff relay.
5. Check for one of the following:
TROUBLESHOOTING
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