Yamaha YZ250 Owner's Service Manual page 244

CARBURETOR AND REED VALVE
4-14
3. Install:
9 Pilot air screw 1
9 Throttle stop screw 2
Note the following installation points:
9 Turn in the pilot air screw until it is lightly
seated.
9 Turn out the pilot air screw by the number of
turns recorded before removing.
Pilot air screw:
1 turn out
*7/8 turns out
(for reference only)
*For EUROPE
4. Install:
9 Starter plunger 1
5. Install:
9 Pilot jet 1
9 Main jet 2
6. Install:
9 Needle valve 1
9 Float 2
9 Float pin 3
NOTE:
9 After installing the needle valve to the float,
install them to the carburetor.
9 Check the float for smooth movement.
ENG