Exhaust valve controller for two-stroke engines

A method for controlling a two-stroke engine comprising:

• measuring a speed of the two-stroke engine;
• and
• adjusting, by a controller, a position of a valve body controlling opening of an exhaust port of the two-stroke engine in an increment of less than or equal to 10 percent of a range of motion of the valve body based on the speed.

A method for installing an exhaust valve in an engine comprising:

• inserting an exhaust valve assembly including a valve body and pivot rod into an opening adjacent a cylinder of the engine, the opening being above an exhaust port of an engine;
• and
• fastening a cover above the valve assembly and covering the opening.

An exhaust valve assembly for an engine comprising:

• a first valve body having a first main valve face positioned adjacent a first cylinder wall of the engine, the first valve face movable to partially obstruct an exhaust port in fluid communication with the first cylinder wall;
• and
• a pivot member secured to the valve body for movement of the valve body, the valve body being secured within a recess adjacent to the first cylinder wall, the recess having a top surface and a bottom surface within which the valve body moves in a limited range of motion less than 90 degrees.