A noise suppression system for an air-cooled internal combustion engine is disclosed. The system may include an acoustically designed shroud forming a cavity and configured for attenuating noise produced by a cooling air fan associated with the engine. In ...

A backpack work machine has a cover member (12) that defines a cooling air passage for forced air cooling around an engine (14) and an exhaust muffler (38). The air passage includes: a first air passage (62) extending along an intake-side lateral face of t...