1986-1987 Honda TRX350 FourTrax 4X4, 1987-1989 TRX350D Foreman 4X4 Service Manual, Page 292Get this manual
TROUBLESHOOTING
POOR PERFORMANCE AT HIGH SPEEDS
Probable Cause
1 Disconnect fue tube at carburetor
FUEL FLOWS FREELY
FUEL FLOW
J 2Check ignition timing and
valve clearance CORRECT
Lack of fuel in tank Clogged fuel line Clogged fuel tank cap breather holeor tube Clogged fuel valve Faulty fuel pump or fuel cut relay Improper valve clearance Faulty COl unit Faulty pulse generator Improper flywheel installation
3Remove carburetor and
check for clogged jet NOT CLOGGED
Clogged jets
4 Check valve timing
CORRECT
Cam sprocket not installed properly