Arctic Cat 425 2011, Service Manual

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Troubleshooting
Problem: Engine will not start or is hard to start (Compression too low)
Condition Remedy
1. Valve clearance out of adjustment
2. Valve guides worn
3. Valve timing incorrect
4. Piston rings worn excessively
5. Cylinder bore worn
6. Spark plug seating poorly
7. Starter motor cranks too slowly - does not turn
1. Adjust clearance
2. Replace cylinder head
3. Correct valve timing - check chain, sprockets, and cam chain
tensioner
4. Replace rings
5. Replace cylinder
6. Tighten plug
7. Check - replace starter motor
Problem: Engine will not start or is hard to start (No spark)
Condition Remedy
1. Spark plug fouled
2. Spark plug wet
3. Magneto defective
4. ECU defective
5. Ignition coil defective
6. High-tension lead open - shorted
1. Clean - replace plug
2. Clean - dry plug
3. Replace stator coil
4. Replace ECU
5. Replace ignition coil
6. Replace high tension lead
Problem: Engine will not start or is hard to start (No fuel reaching the throttle body
Condition Remedy
1. Gas tank vent hose obstructed
2. Fuel hose obstructed
3. Fuel screens obstructed
4. Fuel pump defective
1. Clean vent hose
2. Clean - replace hose
3. Clean - replace inlet screen - valve screen
4. Replace fuel pump
Problem: Engine stalls easily
Condition Remedy
1. Spark plug fouled
2. Magneto defective
3. ECU defective
4. Valve clearance out of adjustment
1. Clean plug
2. Replace stator coil
3. Replace ECU
4. Adjust clearance
Problem: Engine noisy (Excessive valve chatter)
Condition Remedy
1. Valve clearance excessive
2. Valve spring(s) weak - broken
3. Rocker arm - rocker arm shaft worn
4. Camshaft worn
5. Valve tappets worn
1. Adjust clearance
2. Replace spring(s)
3. Replace arm - shaft
4. Replace camshaft
5. Replace tappets
Problem: Engine noisy (Noise seems to come from piston)
Condition Remedy
1. Piston - cylinder worn
2. Combustion chamber carbon buildup
3. Piston pin bore worn
4. Piston pin worn
5. Piston rings - ring groove(s) worn
1. Replace - service piston - cylinder
2. Clean chamber
3. Replace piston
4. Replace piston pin
5. Replace rings - piston
Problem: Engine noisy (Noise seems to come from timing chain)
Condition Remedy
1. Chain stretched
2. Sprockets worn
3. Tension adjuster malfunctioning
1. Replace chain
2. Replace sprockets
3. Repair - replace adjuster
Problem: Engine noisy (Noise seems to come from crankshaft)
Condition Remedy
1. Bearing worn - burned
2. Lower rod-end bearing worn - burned
3. Connecting rod side clearance too large
1. Replace bearing
2. Replace crankshaft
3. Replace crankshaft
Problem: Engine noisy (Noise seems to come from transmission)
Condition Remedy
1. Gears worn - chipped
2. Splines worn
3. Primary gears worn - chipped
4. Bearings worn
5. Bushing worn
1. Replace gears
2. Replace shaft(s)
3. Replace gears
4. Replace bearings
5. Replace bushing
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