Yamaha VMX12 2001 Service Manual page 370

SHAFT DRIVE
Inspection notes
1. Inves tigate any unusual noises.
The following noises may indicate a
mechanical defect:
a. A rolling "rumble" during coasting, accelera-
tion or deceleration (increases with the rear
wheel speed, but does not increase with
higher engine or transmission speeds).
Diagnosis: Possible wheel bearing damage
b. A whining noise that varies with accelera-
tion and deceleration.
Diagnosis: Possible incorrect reassembly or
too little gear backlash
WARNING
@
Insufficient gear backlash is extremely
destructive to the gear teeth. If a test ride,
following reassembly,
symptoms, stop riding immediately to mini-
mize gear damage.
@
c. A slight "clunk" evident at low speed opera-
tion (not to be confused with normal motor-
cycle operation).
Diagnosis: Possible broken gear teeth
WARNING
@
Stop riding immediately if broken gear
teeth are suspected. This condition could
result in the shaft drive assembly locking
up, causing a loss of control and possible
injury to the rider.
@
7 - 95
CHAS
indicates these