Secondary air feed control device of an internal combustion engine

摘要

Disclosed is an internal combustion engine comprising a carburetor and a secondary air feed control valve for feeding secondary air into the exhaust system of the engine from the air pump driven by the engines. The engine further comprises a temperature detector for indicating whether the warm-up of the engine is completed, and a gear position detector for indicating whether the shift gear of the transmission of the engine is in the top gear position. A relatively lean air-fuel mixture is fed into the cylinder of the engine and a relatively small amount of secondary air is fed into the exhaust system when the shift gear of the transmission is in the top gear position after completion of the warm-up of the engine.