Abstract: An internal combustion engine has a cooling jacket defined in the cylinder block for cooling at least an exhaust side of the cylinder. The cooling jacket at least partially surrounds the cylinder and includes a first cooling passage positioned between the exhaust passage and the first auxiliary exhaust passage, and a second cooling passage positioned between the exhaust passage and the second auxiliary exhaust passage. The cooling jacket on at least the exhaust side of the cylinder comprises an upper portion and a lower portion which are in fluid communication with each other via at least one of the first cooling passage and the second cooling passage.

Abstract: An internal combustion engine has a cooling jacket defined in the cylinder block for cooling at least an exhaust side of the cylinder. The cooling jacket at least partially surrounds the cylinder and includes a first cooling passage positioned between the exhaust passage and the first auxiliary exhaust passage, and a second cooling passage positioned between the exhaust passage and the second auxiliary exhaust passage. The cooling jacket on at least the exhaust side of the cylinder comprises an upper portion and a lower portion which are in fluid communication with each other via at least one of the first cooling passage and the second cooling passage.

Abstract: A piston for a two-stroke internal combustion engine has a crown and a skirt extending from the crown. The skirt defines a reciprocation axis of the piston. A circumferential piston groove is defined in the crown. An annular ring carrier is disposed in the piston groove. A circumferential carrier groove is defined in the ring carrier, the carrier groove being concentric with the piston groove. A retainer is disposed in the carrier groove. The retainer extends at least in a radial direction of the piston into the ring carrier. The carrier groove is adapted to receive a piston ring and the retainer is adapted to prevent rotational motion of the piston ring in the carrier groove, the rotational motion being about the reciprocation axis. Two-stroke internal combustion engines are also disclosed.

Abstract: A shifting sleeve for selectively engaging a transmission gear in a vehicle transmission is provided. The transmission gear has at least one opening defined therein. The shifting sleeve comprises at least one tooth for selectively engaging the at least one opening defined in the transmission gear. The at least one tooth extends from the shifting sleeve body and has a first portion, a second portion and a third portion. The first portion has a top surface disposed at a first height and the second portion has a top surface disposed at a second height, the first height being greater than the second height. The third portion is disposed between the first and second portions, and has a top surface disposed at an angle and extending between the top surfaces of the first and second portions.

Abstract: A shifting sleeve for selectively engaging a transmission gear in a vehicle transmission is provided. The transmission gear has at least one opening defined therein. The shifting sleeve comprises at least one tooth for selectively engaging the at least one opening defined in the transmission gear. The at least one tooth extends from the shifting sleeve body and has a first portion, a second portion and a third portion. The first portion has a top surface disposed at a first height and the second portion has a top surface disposed at a second height, the first height being greater than the second height. The third portion is disposed between the first and second portions, and has a top surface disposed at an angle and extending between the top surfaces of the first and second portions.