1987 Honda Fourtrax TRX 250X Service Manual, Page 49Get this manual
FUEL SYSTEM Install the needle clip on the jet needle(11 JET NEEDLE
STANDARD SETTING: 3rd groove (2) 3rd GROOVE
Assemble the piston throttle valveInstall the throttle valve 8rm using the two attaching screws
I THROTTLE VALVE (21 JET NEEDLE