Throttling passageway to decrease coast-down time of lawn mower engines

Abstract From the Canadian patent

Disclosed herein is a lawn mower including a rotatable cutter blade, a reciprocating internal combustion engine drivingly connected to the cutter blade and a venting arrangement for venting the engine cylinder combustion chamber at engine shut down to decrease the engine coast-down time. The venting arrangement includes a flow passage having an inlet port which opens into the combustion chamber and a discharge port which either opens directly to the atmosphere is, connected in communication with the engine crankcase or is, connected in communication with the engine exhaust system. Venting of the combustion chamber through the flow passage is selectively controlled by a valve which is …