Abstract: A four stroke internal combustion engine includes a cylinder head having a valve train having reduced profile that permits access to a spark plug assembly located therein.

Abstract: A control tensioner device for adjusting and maintaining the tension in a flexible linkage in an engine includes a retainer having a central passageway extending therethrough. At least a portion of the central passageway contains a first set of threads. The control tensioner device further includes an adjustment element having a second set of threads. The adjustment element is sized to be threadably received within the central passageway. The adjustment element is adapted to apply pressure on the flexible linkage to maintain the tension. The first set of threads and second set of threads are sized to permit minor relative movement between the retainer and the adjustment element. Furthermore, the first set of threads and second set of threads are sized to be borderline self-locking such that the first and second sets of threads engage in response to minor relative movement between the retainer and the adjustment element.

Abstract: A four stroke internal combustion engine having a flexible arrangement is disclosed such that the engine can be easily configured for supercharged or normally aspirated operation. The engine includes a cooling system that includes both closed loop and open loop cooling systems for improved cooling efficiency. A power take off housing located on one end of the crankcase. Various engine components are operatively coupled to the crankshaft within the power take off housing including a cam shaft for a valve actuation assembly, a generator, an engine starting mechanism, a balance shaft, and a supercharger. The engine contemplated in accordance with the present invention also includes a dry sump lubrication system having lubricant separator for separating lubricant from blow-by gas within the engine.

Abstract: A clutch (1) for a motorcycle, having intermeshing plates (9, 10) associated with an inner and outer cage (22 and 23, respectively), and having a release actuator (3) for a pusher element (5) loaded by at least one clutch spring (8) for applying pressure on the plates (9, 10). The pusher element (5) is operable by a force opposite to the closing force of the clutch spring (8) in dependence on the engine load via a control means (11).