Abstract: A floatless carburetor with a fuel reservoir in communication with the carburetor throttle bore includes an integral primer system which is operable to introduce fuel directly into both the carburetor throttle bore and the fuel reservoir. A plurality of check valves control flow of fuel from the fuel tank into the primer system and into the throttle bore and fuel reservoir. The carburetor and primer system are adapted to be operated in conjunction with an impulse-type fuel pump, wherein the primer system is operable to manually pump fuel into the reservoir when the fuel pump is not functioning.

Abstract: A manually actuable primer for an internally vented float regulated fuel bowl type carburetor employs an arrangement for minimizing variations in fuel mixture richness resulting from variations in air intake path restrictions as might be created by a clogged air filter includes a bifurcated float bowl air vent conduit with one branch communicating with the carburetor bore in the region of the Venturi and the other branch communicating with the bore outside the region of the Venturi along with an arrangement for directing displaced fuel from the fuel supply chamber directly into a conduit which normally conveys fuel from a fuel well to the Venturi region, the directing arrangement being formed as an annular insert for the fuel well, the aperture of which forms the fixed fuel metering orifice of the carburetor.