1980 Ski-Doo Shop Manual, Page 67Get this manual
SECTION 03 SUB-SECTION 02, (ENGINES)
ROTARY VALVE &COOLANT
CLEANING
Discard all all seals and "0" nngs
Clean all metal components in non-ferrous metal cleaner
For example: 132 opening 52 closlOg USing angle findermark crankcase at 132 from bottom edge of magneto side IOlet port
DISASSEMBLYASSEMBLY
Torque to 20 N'm (15 ft-Ibs)Rotary valve adjustment when replacing crankcase having no timing marksREQUIRED TOOLS