Bombardier SeaDoo 2001 factory shop manual, Page 63Get this manual
Section 03 TROUBLESHOOTING Subsection 01 (TROUBLESHOOTING CHART)
ENGINE CONTINUALLY BACKFIRES
OTHER OBSERVATION Weak spark Spark plugs Ignition timingTDC setting Rotary valve (if so equipped) Carburetor (if so equipped) Engine POSSIBLE CAUSE Fouled, defective spark plugs Malfunction of rev limiter in MPEM Spark plug leads or wiring reversed Incorrect setting Sheared flywheel key Incorrect timing Carburetion too lean Intake leakcrankshaft seal failure (carburetor models) REMEDY Cleanreplace Cleanreplace, refer to section ELECTRICAL SYSTEM Check with wiring diagram Checkreset, refer to section ELECTRICAL SYSTEM Checkreplace, refer to sections ELECTRICAL SYSTEM and ENGINE Checkreset, refer to ENGINE Checkadjust, refer to section FUEL SYSTEM Pressure check engine, refer to section ENGINE