Fuel supply system for gas engine

Abstract

A fuel supply system (30; 80) includes an intake flow passage (32) communicating with an intake port (18) of a gas engine (11), a fuel shut-off valve assembly (35) for blocking a fuel supply passage (34) to prevent supply of a gas fuel to a fuel mixer (33), a vacuum flow passage (36) communicating with a vacuum actuator (56) of the fuel shut-off valve assembly (35) and a crank chamber (28) of the gas engine (11), and means (37; 82) for holding the vacuum flow passage (36) open when the gas engine (11) starts, such that a vacuum produced in the crank chamber (28) is used to actuate the vacuum actuator (56) for switching the fuel shut-off valve assembly (35) to an open position allowing supply of the gas fuel to the fuel mixer (33). (Fig. 2).