2003 Ski-Doo REV Series Factory Shop Manual, Page 92Get this manual
Section 03 TROUBLESHOOTING Subsection 05 (ELECTRICAL SYSTEM)
SYMPTOM CONDITION TESTINSPECTION
FOULED (BLACK) SPARK PLUG TIPNORMAL USE1Check carburetoraCarburetion is too richAdjust according to specifications (refer to TECHNICAL DATA)2Check if choke is partially openaChoke is partially openAdjust according to specifications3Check injection oil consumptionaInjection pump flow is too highAdjust according to specifications or replace4Check oil qualityaPoor quality oil (creation of deposits)Use BOMBARDIER injection oil5Check engine for leaksaLeaking center seal on crankshaftReplace
SYMPTOM CONDITION TESTINSPECTION