Yamaha YZ450FT Automobile User Manual


 
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INSP
ADJ
IDLE SPEED ADJUSTMENT/
VALVE CLEARANCE ADJUSTMENT
EC35M021
IDLE SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Adjust:
Idle speed
VALVE CLEARANCE ADJUSTMENT
N
OTE:
The valve clearance should be adjusted
when the engine is cool to the touch.
The piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
Seat
Fuel tank
Refer to SEAT, FUEL TANK AND SIDE
COVERS section in the CHAPTER 4.
2. Remove:
Carburetor
Refer to CARBURETOR section in the
CHAPTER 4.
Spark plug
Engine stay (upper)
Cylinder head cover
Refer to CAMSHAFTS section in the
CHAPTER 4.
Adjustment steps:
Adjust the pilot screw.
Refer to PILOT SCREW ADJUSTMENT
section.
Turn the throttle stop screw 1 until the
specified engine idling speed.
N
OTE:
Using a digital engine tachometer for idle
speed adjustment, detect the engine idling
speed by bringing the sensing element c of
the engine tachometer close to the ignition
coil 2.
To increase idle speed
Turn the throttle stop screw
1
in
a
.
To decrease idle speed
Turn the throttle stop screw
1
out
b
.
Engine idling speed:
1,900 ~ 2,100 r/min
c
2