1970-1979 Ski-Doo Snowmobiles Service Manual, Page 105Get this manual
98 2If welch plugs were removed, install new plugs (convex side up) and tap plug with hammer and punch until plug is flatEnsure that plug completely seals opening3Place spring, washer, and packing on idle speed mixture screw and install in carburetorLubricate packing with petroleum jelly4Install high-speed needle with spring, washer, and packingLubricate packing with petroleum jelly5On HR and HD types with fixed main jet install jet with gasket and turn counterclockwise to tighten6Insert choke friction spring and ball into carburetor and hold in position while installing choke shaftNOTE: On HRM carburetors install primary venturi with largest section towardfront ofcarburetor
CHAPTER FIVE