Yamaha YZ250(W)/W1, Owner'S Service Manual

Page: 240 / 596

4-11
ENG
CARBURETOR AND REED VALVE
EC464401
Jet needle
1. Inspect:
9 Jet needle
1
Bends/Wear
→
Replace.
9 Clip groove
Free play exists/Wear
→
Replace.
9 Clip position
*For EUROPE
EC464511
Float height
1. Measure:
9
Float height
a
Out of specification
→
Adjust.
Standard clip position:
No.2 Groove
*No.3 Groove
Float height:
5.5~7.5 mm (0.22~0.30 in)
Measurement and adjustment steps:
9 Hold the carburetor in an upside down posi-
tion.
9 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.
9 If the float height is not within specification,
inspect the valve seat and needle valve.
9 If either is worn, replace them both.
9 If both are fine, adjust the float height by
bending the float tab
b
on the float.
9 Recheck the float height.
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