1978 Ski-Doo Shop Manual, Page 240Get this manual
SECTION 04 SUB-SECTION 05, (CARBURETOR)
FUEL PUMPMIKUNI TYPE
To install new valve, proceed as follows:Place new valve flat on its seat- Insert 332" pin punch inside valve holder and lubricate tip of holder with drop of oilPush holder into carburetor body as illustrated
Valve holder
CLEANINGINSPECTION
ONE OUTLET TWO OUTLETS
The entire pump should be cleaned with general purpose solvent before disassemblyFuel pump components should be cleaned in general purpose solvent and dried with compressed airWARNING: Solvent with low flash point such as gasoline, naphtha, benzol, etc should not be used as each is flammable and explosiveInspect diaphragmThe pumping area should be free of holes or imperfectionsReplace as neededCheck fuel pump valves operation as follows: Connect length of clean plastic tubing to the inlet nipple and alternately apply pressure and vacuum with the mouthThe inlet valve should release with pressure and hold under vacuumRepeat the same procedure at the outlet nippleThis time the outlet valve should hold with pressure and release under vacuum