2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 334Get this manual
TROUBLESHOOTING
POOR PERFORMANCE AT LOW AND IDLE SPEED
1Pilot Screw Inspection Check carburetor ilot screw adjustment
Is the adjustment correct?
NO YESSee page 622GO TO STEP 2
2Intake Air Leak Inspection Check for leaking carburetor insulator
Is there leaking?
YES NOLoose carburetor insu lator bands Damaged insulatorGO TO STEP 3
3Spark Test Perform spa rk test
Is there weak or intermittent spark?