Internal combustion engine with altitude compensation device

摘要

An altitude compensation device for an internal combustion engine having a vacuum-operated ignition timing advancer and a carburetor has an atmospheric pressure variation responsive valve operative to control the air bleed of the carburetor and the vacuum fed to the vacuum advancer such that, as the atmospheric air pressure is lowered due to increase of the altitude, the air flow into the advancer vacuum chamber is decreased to advance the ignition timing while the air flow into the carburetor air bleed passage is increased to increase the air-fuel ratio of the air-fuel mixture produced by the carburetor.