Honda TRX400EX FOURTRAX 1999, Service Manual

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TROUBLESHOOTING
From page
Possible cause
Remove cylinder head cover Valve train not lubricated
and inspect lubrication properly
Valve train lubricated properly
I
11.
12.
Overheating Check for engine overheating
-
Not overheating
Accelerate or run at high speed - Engine knocks
Engine does not knock
Clogged oil passage
Clogged oil orifice
Excessive carbon build-up in
combustion chamber
Use
of poor quality fuel
Clutch slipping
Lean fuel mixture
Worn piston and cylinder
Use of poor quality fuel
Excessive carbon build-up in
combustion chamber
Ignition timing too advanced
(Faulty
Lean fuel mixture
POOR PERFORMANCE AT LOW AND IDLE SPEED
Possible cause
1. Check carburetor pilot screw Incorrect
adjustment
Correct
I
2. Check for leaking carburetor
~-
insulator
No
leak
I
Leaking
Weak or intermittent spark
3.
Perform spark test
Good spark
Incorrect
4. Check ignition timing
See section 5
Loose carburetor insulator bands
Damaged carburetor insulator
Faulty carburetor insulator O-ring
Faulty spark plug
Fouled spark plug
Loose or disconnected ignition sys-
tem wires
Broken or shorted spark plug wire
Faulty ignition coil
Faulty ignition pulse generator
Faulty exciter coil
Faulty engine stop switch
Faulty ignition switch
Faulty ignition control module
Faulty
ICM
Faulty ignition pulse
20-3