1999 Ski-Doo Factory Shop Manual Volume One, Page 73Get this manual
Section 03 TROUBLESHOOTING Subsection 04 (TRANSMISSION AND BRAKE SYSTEMS)
SYMPTOM CONDITION TestInspection
BELT "FLIP-OVER" AT HIGH SPEEDNORMAL USE1Check pulley alignmentaPulley misalignmentAlign pulley according to specifications (refer to TECHNICAL DATA 10)2Check drive belt identification numberaUsing unspecified type of beltReplace belt with an appropriate drive belt