Idle Speed Adjustment - Yamaha YZ450F(V) Owner's Service Manual

VALVE CLEARANCE ADJUSTMENT
2
c

IDLE SPEED ADJUSTMENT/

EC35M021
IDLE SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Adjust:
• Idle speed
Adjustment steps:
• Adjust the pilot screw.
Refer to "PILOT SCREW ADJUSTMENT"
section.
• Turn the throttle stop screw 1 until the
specified engine idling speed.
NOTE:
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.
VALVE CLEARANCE ADJUSTMENT
NOTE:
• 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:
• Spark plug
• Engine upper bracket
• Hot starter plunger
Refer to "CARBURETOR" section in the
CHAPTER 4.
• Cylinder head cover
Refer to "CAMSHAFTS" section in the
CHAPTER 4.
3 - 18
INSP
ADJ
Engine idling speed:
1,900 ~ 2,100 r/min