Yamaha YZ250F Owner's Service Manual page 112

CARBURETOR
2. Inspect:
• Main jet 1
• Pilot jet 2
• Needle jet 3
• Starter jet 4
• Pilot air jet 5
• Leak jet 6
Damage → Replace.
Contamination → Clean.
NOTE:
• Use a petroleum based solvent for cleaning.
Blow out all passages and jets with com-
pressed air.
• Never use a wire.
Needle valve
1. Inspect:
• Needle valve 1
• Valve seat 2
Grooved wear a → Replace.
Dust b → Clean.
• Filter c
Clogged → Clean.
EC464301
Throttle valve
1. Check:
• Free movement
Stick → Repair or replace.
NOTE:
Insert the throttle valve 1 into the carburetor
body, and check for free movement.
EC464401
Jet needle
1. Inspect:
• Jet needle 1
Bends/wear → Replace.
• Clip groove
Free play exists/wear → Replace.
• Clip position
Standard clip position:
No.4 Groove
4 - 12
ENG