Patent ID: 7490584

Claim:
A fuel enrichment cold start/run circuit for a carbureted internal combustion engine having a fuel pump pumping fuel from a fuel tank to a float bowl of a carburetor which supplies an air fuel mixture to an intake manifold of said engine, said circuit comprising an inlet receiving pumped fuel from said fuel pump, an outlet supplying fuel to said intake manifold of said engine, and an enrichment valve between said inlet and said outlet and actuatable between an open condition passing fuel from said inlet to said outlet, and a closed condition blocking the passing of fuel from said inlet to said outlet, said enrichment valve being actuated to said closed condition upon a given warmed-up state of said engine, wherein said circuit comprises a first supply jet supplying fuel from said inlet to a plenum, a second supply jet supplying fuel from said inlet to said plenum in parallel with said first jet, said plenum supplying fuel to said outlet, said valve being between said plenum and said outlet, a timer closing said second jet after a timing interval following a cold start, such that upon initial cold start, fuel flows through both said first supply jet and said second supply jet into said plenum, and after said timing interval, fuel flows through said first supply jet but not said second supply jet into said plenum.