1969 Ski-Doo Snowmobiles Service Manual, Page 72Get this manual
SECTIONMAIN NOZZLE SYSTEM
TROUBLE
1 Lean operation at high speeds
Adjustment set too lean Dirt in nozzle system
Readjust Blowout channels with compressed air Replace packing
Adjustment packing damaged
Main fuel check valve damaged Main fuel check valve not seated correctly in body casting
Inlet control lever incorrectly set