Yamaha TT-R90(R) Owner's Service Manual page 154

CARBURETOR
EC464000
INSPECTION
Carburetor
1. Inspect:
Carburetor body
G
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
2. Inspect:
Main jet 1
G
Pilot jet 2
G
Needle jet 3
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 → Clean.
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.
4 - 4
ENG