1972 Ski-Doo Shop Manual, Page 169Get this manual
2-07-01 Engine
CARBURETOR
GENERAL
The Tillotson carburetor used on the Bombardier-Rotax engine is complete fuel system incorporating carburetor, fuel pump and fi Iter in the same unitA diaphragm controlled metering system allows precise fuel metering to the engine at extreme ti It angles and prevents fuel level changes due to vibrationThe dual venturi multiplies the venturi pressure drop causing fine atomization of the fuel that is delivered from the main fuel nozzle so that the fuel reaches the engine as combustible fog instead of fluid streamThe venturi is specially designed section of the carburetor throat where the area is reducedSince the same volume of air flows through all sections of the carburetor throat, this reduction in area increases the velocity of the air passing through this sectionThis increase in velocity, produces vacuum at its point of maximum restrictionUsually fuel jet is installed at that point with the result that the fuel drawn from the jet mixes with the incoming airThis mixing of fuel and air is known as vaporizationCARBURETOR OPERATION