pressure and crank case low pressure the channel is formed by preferably by drilling one small hole with size range of about 3 5 mm on each reed stopping deck along the cylinder wall to the depth of about 0 1 to about 0 3 mm under upper piston ring this depth is very critical too deep will cause the high pressure releasing too earlier which will cause efficiency lost too shallow will cause the high pressure not be able to release in short time also several holes are drilled through the piston outside diameter between the piston rings when the piston completes the compression stroke a through channel is formed between the clearance volume and the crank case from an opening on the cylinder bore deck that is interconnected to openings on the outer diameter of the sides of the piston between the piston rings because of the pressure balance when the channel is opened the high pressure in the clearance volume is released suddenly and the new pressure will be equal to suction pressure in an alternate embodiment a channel is formed by drilling a hole on the center of piston from the crankcase side with two diameters a smaller size for the opening and a bigger size for remainder of the channel a metal ball spring and set screw are mounted at the opening the diameter of opening on the piston is smaller than the diameter of the metal ball but the internal diameter of the channel on the piston is bigger than the diameter of metal ball the transition between the sizes of the holes.