1997 Ski-Doo Factory Shop Manual Volume Two, Page 25Get this manual
Section 02 TROUBLESHOOTING Sub-Section 02 (ENGINE)
SYMPTOM CONDITION TestInspection
PISTON RING AND CYLINDER SURFACES ARE GROOVED NORMAL USE 1Check oil qualitya.Poor oil qualityUse Bombardier Rotax oil2Check injection pump and its hosesa.Inadequate injection pump adjustment andor defective hosesAdjust pump according to specifications (refer to ENGINE 03) andor replace hoses