Abstract: A motorcycle power transmission assembly including an engine, a transmission, a drive assembly, and a starter assembly. The engine includes a crankcase, and the transmission includes a transmission case coupled to the crankcase to define an engine-transmission assembly. The drive assembly includes a drive housing coupled to the engine-transmission assembly to define a drive chamber. The drive housing including an opening, and the drive assembly further includes a starter gear. The starter assembly is mounted to the drive housing and includes a nose portion that extends through the opening. The nose portion includes a pinion gear adapted to engage the starter gear.

Abstract: A compensator assembly for a motorcycle engine including a hub and a compensator coupled to the engine crankshaft. The compensator is axially moveable along the crankshaft axis and a sprocket is supported for rotation with respect to the crankshaft. Cam surfaces on the compensator and the sprocket cooperate to transfer engine torque from the crankshaft to the sprocket. A spring biases the compensator into engagement with the sprocket and a resilient member is positioned between the hub and the compensator to resiliently limit axial movement of the compensator toward the hub. Torque pulses from the engine are damped by allowing relative rotation between the sprocket and the crankshaft.

Abstract: A drive assembly for a motorcycle including an engine having an output shaft and a transmission having an input shaft parallel to the output shaft and coupled to the output shaft. The engine includes a crankcase having a first interface portion with a first non-horizontal mounting surface. The transmission includes a transmission case having a second interface portion with a second non-horizontal mounting surface arranged to engage the first non-horizontal mounting surface. The second interface portion of the transmission case includes at least one fluid passage for the flow of fluid to or from the engine.

Abstract: A lubrication system for a motorcycle engine includes a camshaft support plate that is separable from an ornamental cam cover. The camshaft support plate at least partially defines a cam chest of the engine. A crankcase defines a crankcase sump and the cam chest defines a cam chest sump. A divider wall is disposed between the crankcase sump and the cam chest sump to prevent oil from draining from one sump into the other. An oil pump is mounted on the camshaft support plate, with a pressure chamber of the oil pump being at least partially defined by the camshaft support plate. The oil pump independently draws oil from the crankcase sump and the cam chest sump through a split-kidney intake assembly. Oil pumped from the sumps is delivered to a reservoir, and is then drawn back out of the reservoir by the oil pump and delivered to components of the engine through a series of oil passages, some of which are defined by the camshaft support plate.

Abstract: A drive assembly for a motorcycle including an engine having an output shaft and a transmission having an input shaft parallel to the output shaft and coupled to the output shaft. The engine includes a crankcase having a first interface portion with a first non-horizontal mounting surface. The transmission includes a transmission case having a second interface portion with a second non-horizontal mounting surface arranged to engage the first non-horizontal mounting surface. The second interface portion of the transmission case includes at least one fluid passage for the flow of fluid to or from the engine.

Abstract: A lubrication system for a motorcycle engine includes a camshaft support plate that is separable from an ornamental cam cover. The camshaft support plate at least partially defines a cam chest of the engine. A crankcase defines a crankcase sump and the cam chest defines a cam chest sump. A divider wall is disposed between the crankcase sump and the cam chest sump to prevent oil from draining from one sump into the other. An oil pump is mounted on the camshaft support plate, with a pressure chamber of the oil pump being at least partially defined by the camshaft support plate. The oil pump independently draws oil from the crankcase sump and the cam chest sump through a split-kidney intake assembly. Oil pumped from the sumps is delivered to a reservoir, and is then drawn back out of the reservoir by the oil pump and delivered to components of the engine through a series of oil passages, some of which are defined by the camshaft support plate.