Patent ID: 8225776

Claim:
A power unit for a portable chain saw, comprising an elongated crank case which extends in a longitudinal direction, an engine having a cylinder and an associated flywheel mounted in the crankcase such that an inner wall of the crank case defines an air guiding passage around a first peripheral portion of the flywheel, said air guiding passage having a open discharge port for directing air at a first side of said cylinder, a muffler mounted on said crank case so as to be spaced from a second side of said cylinder opposite said first side, an ignition coil, and a coil support connected to said crank case and supporting said ignition coil so as to be adjacent a second portion of said flywheel near said second side of said cylinder, said coil support extending upwardly and providing an insulating gap with a side of said muffler in a width direction of said crank case perpendicular to said longitudinal direction.