2011 Arctic Cat 350/425 ATV Service Manual, Page 27Get this manual
Troubleshooting Problem: Engine will not start or is hard to start (Compression too low) Condition Remedy
1Valve clearance out of adjustment 2Valve guides worn 3Valves timing incorrect 4567Piston rings worn excessively Cylinder bore worn Spark plug seating poorly Starter motor cranks too slowlydoes not turn 1Adjust clearance 2Replace cylinder head 3Correct valve timingcheck chain, sprockets, and cam chain tensioner 4Replace rings 5Replace cylinder 6Tighten plug 7Checkreplace starter motor
Problem: Engine will not start or is hard to start (No spark) Condition Remedy
123456Spark plug fouled Spark plug wet Magneto defective CDI unit defective Ignition coil defective High-tension lead openshorted 123456Cleanreplace plug Cleandry plug Replace magneto Replace CDI unit Replace ignition coil Replace high tension lead
Problem: Engine will not start or is hard to start (No fuel reaching the carburetor (350)throttle body (425) Condition Remedy
12345Gas tank vent hose obstructed Carburetor float valve defective (350) Fuel hose obstructed Fuel screens obstructed Fuel pump defective (425) 12345Clean vent hose Replace valve Cleanreplace hose Cleanreplace inlet screenvalve screen Replace fuel pump