Yamaha WR450F Manuel D'atelier Du Proprietaire page 326

CARBURETOR
Measurement and adjustment steps:
• Hold the carburetor in an upside down
position.
NOTE:
• Slowly tilt the carburetor in the opposite
direction, then take the measurement
when the needle valve aligns with the float
arm.
• If the carburetor is level, the weight of the
float will push in the needle valve, resulting
in an incorrect measurement.
• Measure the distance between the mating
surface of the float chamber and top of the
float using a vernier calipers.
NOTE:
The float arm should be resting on the nee-
dle valve, but not compressing the needle
valve.
• If the float height is not within specification,
inspect the valve seat and needle valve.
• If either is worn, replace them both.
• If both are fine, adjust the float height by
bending the float tab b on the float.
• Recheck the float height.
EC464600
Float
1. Inspect:
• Float 1
Damage → Replace.
Starter plunger
1. Inspect:
• Cold starter plunger 1
• Hot starter plunger 2
Wear/damage → Replace.
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ENG