Yamaha BEARTRACKER YFM250XC, Service Manual

Page: 307 / 398

9 - 3
TRBL
SHTG
FAULTY DRIVE TRAIN
FAULTY DRIVE TRAIN
The following conditions may indicate damaged shaft drive components:
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.
Symptoms Possible Causes
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.
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.
9