Signal indicating device on internal combustion engines

摘要

A signal indicating device for an internal combustion engine. The internal combustion engine has a sound absorbing shell surrounding the engine body. An air intake pipe is mounted on the engine and an air intake filter is mounted on the inlet end of the air intake pipe. The signalling device is provided to indicate the degree of contamination of the air filter. The signaling device can be a visual signal or an audible signal.