Yamaha YZ250 2004 Manuel D'atelier Du Proprietaire page 544

SETTING
1. Too rich at intermediate speeds
Rough engine operation is felt and the
engine will not pick up speed smoothly. In
this case, step up the jet needle clip by one
groove and move down the needle to lean
out the mixture.
2. Too lean at intermediate speeds
The engine breathes hard and will not pick
up speed quickly.
Step up the jet needle clip by one groove
and move up the needle to enrich the mix-
ture.
7-5
TUN