Faulty Drive Train - Yamaha YFM250XL(C) Service Manual

FAULTY DRIVE TRAIN

The following conditions may indicate damaged shaft drive components:
Symptoms
1.A pronounced hesitation or "jerky" move-
ment during acceleration, deceleration, or
sustained speed. (This must not be con-
fused with engine surging or transmission
characteristics.)
2.A "rolling rumble" noticeable at low speed;
a high-pitched whine; a "clunk" from a
shaft drive component or area.
3.A locked-up condition of the shaft drive
mechanism, no power transmitted from
the engine to the rear wheels.
NOTE:
Areas A, B, and C above may be extremely difficult to diagnose. The symptoms are quite sub-
tle and difficult to distinguish from normal machine operating noise. If there is reason to
believe these components are damaged, remove the components and inspect them.
FAULTY DRIVE TRAIN
Possible Causes
A.Bearing damage.
B.Improper gear lash.
C.Gear tooth damage.
D.Broken drive shaft.
E.Broken gear teeth.
F.Seizure due to lack of lubrication.
G.Small foreign objects lodged between the
moving parts.
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TRBL
SHTG
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