Arctic Cat Sno Pro 120 2011, Service Manual

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Problem: Engine Loses Power or Runs on One Cylinder
Condition Remedy
1. Sensor faulty
2. Spark plug fouled
3. External coil faulty
4. Gas tank vent — hose obstructed
5. Secondary compression low
6. Fuel pressure regulator faulty
7. Pick-up valve(s) obstructed — out of position
8. Oil-injection pump malfunctioning — adjusted incor-
rectly
9. Throttle bodies out of synchronization
10. Injector faulty
11. Dropping resistor faulty
1. Check LED for trouble code — repair — replace problem
circuit or sensor
2. Replace spark plugs
3. Service — replace coil
4. Service — replace vent hose
5. Service engine
6. Replace regulator
7. Replace — relocate pick-up valve(s)
8. Replace — bleed — adjust oil-injection pump
9. Replace throttle bodies from a similar engine — if prob-
lem is corrected, replace the original assembly
10. Replace injector
11. Test resistor — replace as necessary
Problem: Engine Backfires
Condition Remedy
1. ECU/CCU LED trouble code
2. Throttle/ignition monitor switch adjusted incorrectly
3. Spark plugs fouled — damaged
4. High tension leads/coil shorting
5. ECU/CCU faulty — damaged
6. Fuel mixture lean
7. Oil-injection pump malfunctioning — adjusted incor-
rectly
1. Service — replace problem component
2. Adjust throttle cable tension — service spring
3. Clean — replace spark plugs
4. Service — replace high tension leads/coil
5. Replace ECU/CCU
6. Repair fuel regulator — injector(s)
7. Replace — bleed — adjust oil-injection pump
Problem: Engine Four-Cycles (Floods Excessively)
Condition Remedy
1. ECU LED trouble code
2. Fuel pressure too high
3. Injector faulty
4. Throttle position sensor faulty
5. Air silencer obstructed
1. Service — replace problem component
2. Replace regulator — hose
3. Replace injector
4. Replace throttle body assembly
5. Remove obstruction
Problem: Engine Stops Suddenly
Condition Remedy
1. Gas tank empty
2. Spark absent
3. ECU/CCU LED trouble code
4. Fuel filter(s) obstructed
5. Fuel pressure low
6. Fuel pump faulty
7. Fuel pump relay faulty
8. Gas tank vent hose obstructed
9. ECU/CCU faulty
10. Fuel hose obstructed — broken — pinched
11. Ignition coil faulty
12. Engine seized
13. Throttle/ignition monitor switch — throttle cable ten-
sion
faulty — adjusted incorrectly
1. Fill tank
2. See No Spark at Spark Plugs sub-section
3. Service — replace problem component
4. Replace filter(s)
5. Replace regulator — hose
6. Service — replace fuel pump
7. Replace relay
8. Service vent hose
9. Replace ECU/CCU
10. Remove obstruction — repair — replace fuel hose
11. Replace ignition coil
12. Service engine
13. Replace throttle control — adjust throttle cable
Problem: Engine Fails to Stop (Continues to Run, Even with All Switches Off)
Condition Remedy
1. ECU/CCU shorted to ground
2. Engine wiring harness connections wet
1. Replace ECU/CCU
2. Clean — dry connections
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