2001 Polaris SLH, Virage PWC Factory Service Manual, Page 59Get this manual
Maintenance General TroubleshootingContinued Rich Fuel Mixture
Symptoms: Fouled spark plugs; black sooty exhaustrough idle, idle unstable; poor fuel economy; rough running ("four cycling"); misses; poor performance; bogs; loads up; backfires (plug fouling) Thermostatpopoff leak, dirty or damaged Carburetor mixture needles damaged or adjusted incorrectly Needle and seat damaged Misuse of choke Fouled spark plugs Fuel pump diaphragm damaged (ruptured) Carburetor synchronization incorrect Needle and seat control arm too high or sticking Collapsed exhaust hose or pipe (restricted) Air intake restricted Brokencracked or poorly sealing reed valve Low compression Ignition problem Anti-siphon valve worn or broken Exhaust hose delaminating presentSymptoms: Engine backfires
Weak spark from fouled, defective, worn or wrong spark plugs Broken reed petals
Symptoms: Engine "pinging" or "knocking"Lean fuel mixture Poor quality, low octane gasoline Incorrect ignition timing Spark plug heat range too high Symptoms: Engine power loss