Yamaha YFZ450S 2003 Service Manual page 243

2
3
3
1
1
4. Check:
• throttle valve 1
1
• throttle valve plate 2
5. Check:
• accelerator pump diaphragm 1
• pilot jet diaphragm 2
• spring 3
2
6. Check:
• jet needle 1
• clip groove
• clip position
7. Check:
• main jet 1
• pilot jet 2
• needle jet 3
• starter jet 4
• pilot air jet 5
• accelerator jet 6
8. Check:
• throttle valve movement 1
6 - 6
CARBURETOR
Scratches/wear/damage → Replace.
Bends/wear/damage → Replace.
Free play/wear → Replace.
Standard clip position
No.4 groove
Bends/wear/damage → Replace.
Blockage → Blow out the jets with com-
pressed air.
Sticks → Replace the throttle valve guide
and the throttle valve.
Insert the throttle valve into the carburetor
body, and check for free movement.
CARB