1986-1989 Honda TRX250 FourTrax 250R Service Manual, Page 49Get this manual
FUEL SYSTEM INST ALLA TI ON
Connect the fuel lineInstall the throttle valve assembly into the carburetor body with throttle valve cut away facing to air cleanerTighten the carburetor top securely
Align the lug on the carburetor with the groove in the connecting tubeTighten the connecting tube band screws securelyTurn the fuel valve" ON" and make sure that the there are no fuel leaksAfter installing the carburetor, make the following adjustmentsthrottle lever free play (page 2-4)- air screw adjustment- idle speed adjustment (page 2-6)Install the seatrear fender
AI RSCREW ADJUSTMENT
Warm the engine up to operating temperature