6-13
PERIODIC MAINTENANCE AND MINOR REPAIR
1
2
8
9
EAU01168
Idle speed adjustment
NOTE:
A diagnostic tachometer must be
used for this procedure.
1. Attach the tachometer. Start
the engine and warm it up for
a few minutes at approximate-
ly 1,000 to 2,000 r/min.
Occasionally rev the engine to
4,000 to 5,000 r/min. The
engine is warm when it quickly
responds to the throttle.
2. Set the idle to the specified
engine speed by adjusting the
throttle stop screw. Turn the
screw in direction
a
to
increase engine speed and in
direction
b
to decrease engine
speed.
EAU00629
Carburetor adjustment
The carburetor is a vital part of the
engine and requires very sophisti-
cated adjustment. Most adjust-
ments should be left to a Yamaha
dealer who has the professional
knowledge and experience to do
so. However, the following may be
serviced by the owner as part of
routine maintenance.
EC000094
c
C
The carburetor was set at the
Yamaha factory after many tests. If
the settings are changed, poor
engine performance and damage
may result.
1.
Throttle stop screw
a
b
1
Standard idle speed:
1,350 ~ 1,450 r/min
NOTE:
If the specified idle speed cannot
be obtained by performing the
above adjustment, consult a
Yamaha dealer.
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