Yamaha YZ250F(P)/LC Owner's Service Manual page 278

CARBURETOR
2. Inspect:
Main jet 1
G
Pilot jet 2
G
Needle jet 3
G
Starter jet 4
G
Main air jet 5
G
Pilot air jet 6
G
Leak jet 7
G
Damage → Replace.
Contamination → Clean.
NOTE:
Use a petroleum based solvent for cleaning.
G
Blow out all passages and jets with com-
pressed air.
Never use a wire.
G
Needle valve
1. Inspect:
Needle valve 1
G
Valve seat 2
G
Grooved wear a → Replace.
Dust b and c → Clean.
NOTE:
Replace the needle valve and valve seat as a
set.
EC464301
Throttle valve
1. Check:
Free movement
G
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
G
Bends/wear → Replace.
Clip groove
G
Free play exists/wear → Replace.
Clip position
G
Standard clip position:
No.4 Groove
4 - 11
ENG