To solve a problem that air is trapped in a fuel feed pipe to a carburetor from a carburetor passage and a fuel tank on the upstream side of a diaphragm, and an engine is hardly started when no fuel is present in the engine using a diaphragm carburetor.

A fuel feed system with a diaphragm carburetor has an air purge system to exhaust trapped air from a fuel feed system. In the air purge system, an exhaust pipe having an outlet opened into an upper part of a fuel tank and an inlet at the position close to a diaphragm chamber of the carburetor is provided, preferably, in an inner passage of the carburetor, or at least in a fuel feed pipe part close to a fuel inlet of the carburetor. In a system having no air purge system, a cord must be pulled about 15 times to start an engine with fuel. According to this system, the cord may be pulled only about several times, and "false-hit" need not be performed during a cold engine start.