Exhaust valve assembly for a two-stroke internal combustion engine and method for cleaning same

A two-stroke internal combustion engine comprising:

• a crankcase;
• a crankshaft disposed at least in part in the crankcase;
• a cylinder block connected to the crankcase;
• a cylinder defined in the cylinder block, the cylinder having a cylinder axis, the cylinder defining a decompression port and an exhaust port, the exhaust port being disposed between the decompression port and the crankshaft with respect to a direction defined by the cylinder axis,
• the cylinder block defining an exhaust passage extending from the exhaust port and a cylinder decompression passage extending from the decompression port;
• a piston movably disposed within the cylinder and being operatively connected to the crankshaft;
• an exhaust valve selectively extending into the exhaust passage, the valve defining a valve decompression passage;
• and
• a valve actuator operatively connected to the exhaust valve, the valve actuator being movable between a first actuator position, a second actuator position and a third actuator position, the second actuator position being intermediate the first and third actuator positions,
• at least a portion of the exhaust valve being in a first valve position when the valve actuator is in the first actuator position,
• at least the portion of the exhaust valve being in a second valve position when the valve actuator is in the second actuator position,
• at least the portion of the exhaust valve being in a third valve position when the valve actuator is in the third actuator position,
• the second valve position being intermediate the first and the third valve positions,
• at least the portion of the valve extending further in the exhaust passage in the first valve position than in the second valve position,
• at least the portion of the valve being withdrawn from the exhaust passage in the third valve position,
• the valve decompression passage fluidly communicating the cylinder decompression passage with the exhaust passage when the valve actuator is in the second actuator position, and
• the cylinder decompression passage not fluidly communicating with the exhaust passage via the valve decompression passage when the valve actuator is in any one of the first and third actuator positions.