1986-1987 Honda TRX350 FourTrax 4X4, 1987-1989 TRX350D Foreman 4X4 Service Manual, Page 53Get this manual
FUEL SYSTEM
PILOT SCREW ADJUSTMENT
The pilot screw is factory pre-setAdjustment is not necessary unless the carburetor is overhauled, new pilot screw is installed or adjustment is necessary for high altitude riding
CAUTION
Damage to the pilot screw seat will occur if thepilot screw is tightened against the seatTurn the pilot screw clockwise until it seats lightly and back it out 1-12 turnsThis is an initial setting prior to the final pilot screw adjustmentWarm the engine up to operating temperatureStop the engine and connect tachometerStart the engine and adjust the idle speed with the throttle stop screw
IDLE SPEED: 1.400 100 rpm
Turn the pilot screw clockwise slowly until the engine stops, and then back it out turnsStart the engine and readjust the idle speed with the throttle stop screw, if necessary
HIGH ALTITUDE ADJUSTMENT
SPECIFICATIONS
Below Between
5,000 ft (1,500 m)
Main jet Pilot screw opening