1999-2002 TRX400EX Fourtrax Service Manual, Page 254Get this manual
20TROUBLESHOOTING ENGINE DOES NOT START OR IS HARD TO START ENGINE LACKS POWER POOR PERFORMANCE AT LOW AND IDLE SPEED
20-1 20-2 20-3
POOR PERFORMANCE AT HIGH SPEED POOR HANDLING
ENGINE DOES NOT START OR IS HARD TO START
Possible cause
1Check fuel flow to carburetor- Not reaching carburetor
Reaching carburetor
Clogged fuel line and strainer Clogged fuel valve Clogged fuel tank breather tube
2Remove and inspect spark plug Good condition