Abstract: A fuel priming system for spark ignited internal combustion engines includes a manually actuated plunger pump for delivering liquid fuel from a tank to a reservoir chamber formed in part by a flexible diaphragm. A fuel injection passage leads from the reservoir chamber through a flow restricting orifice to an injection point formed in the engine intake air flow passage downstream of the carburetor venturi. The injection system provides for enriching the fuel-air mixture during cold starting while minimizing the chance of engine flooding. The finite fuel volume in the reservoir chamber also provides a sufficient quantity of fuel for automatic control of a rich fuel-air mixture during engine warm-up.

Abstract: A system for priming and temporarily enriching the air/fuel mixture for a crankcase scavenged, two-cycle engine having a fuel pump supplying fuel to a carburetor for mixture with air for delivery to an induction manifold leading to the engine crankcase where it is compressed and transferred to the cyclinder combustion chamber through a passage, the system includes a solenoid valve controlled by a switch so the valve opens when the switch is turned on to start the engine. The valve inlet is connected to the fuel pump. The valve outlet is connected to a conduit means which is connected to the transfer passage to inject fuel to prime the engine. The valve outlet is also connected to a conduit connected to the induction manifold to enrich the air/fuel mixture therein. The fuel in conduits is drawn into the manifold after said valve closes to thereby enrich the air/fuel mixture long enough for the engine to warm up.