Exhaust valve throttling mechanism for two-stroke engine

Abstract

An exhaust port throttling mechanism for a two-stroke engine. The engine includes a plurality of in-line cylinders each having exhaust port means disposed to be closed during reciprocating movement of the piston. The engine block is provided with a passage which intersects each exhaust port means, and a shaft is mounted for rotation within the passage and carries a plurality of butterfly-type valves that are disposed to open and close each exhaust port means. When used with a V-6 engine, having two banks of in-line cylinders, a shaft carrying the valves is employed for each bank and the corresponding ends of the shafts are interconnected by meshing gear segments. One of the gear segments is connected through a linkage to the throttle lever for the engine, so that the valves will be moved by actuation of the throttle lever between a substantially closed position at low speeds to an open position at high speeds. A biasing mechanism is incorporated with the gear segments to bias the valves to a closed position, and an adjusting mechanism can be incorporated to manually adjust the closed position of the valves.