Abstract: Automatic neutral finder apparatus for a motorcycle transmission, for automatically locating and positively engaging the transmission's neutral position. A preferred embodiment of the apparatus includes a shifter cam rotatable about an axis through predetermined rotational displacements for effecting gear shifts and having a neutral position; a stop indexed to the neutral position of the cam; a plunger actuable for engaging the stop to stop rotation of the cam when the cam is at its neutral position; and a circuit associated with the plunger and including a switch operable by the motorcycle operator for actuating the plunger to engage the stop. The plunger is further actuable for disengaging the stop, and the switch is preferably operable by the motorcycle operator for actuating the plunger to disengage the stop.

Abstract: Engine brace apparatus for an overhead-valve engine comprising a crankcase, a cylinder, a cylinder head and a rocker arm box in operative securement, with pushrods communicating between the crankcase and the rocker arm box, and a rigid elongate member securing the rocker arm box to the crankcase outwardly of the pushrods. The brace adds rigidity to a conventional overhead-valve engine and structurally ties together the engine's rocker arm box, cylinder head, cylinder and crankcase, and prevents the engine's pushrods from lifting the rocker arm box.

Abstract: A motorcycle reverse gear transmission that precludes inadvertent shifting into a forward gear when in reverse and inadvertent shifting into reverse when in a forward gear. The reverse gear transmission requires the forward ratio gears to be in neutral before shifting into reverse; during shifting, the apparatus locks the forward gears in neutral and then engages the reverse gear. The forward ratio gears are unlocked from neutral after the reverse gear is disengaged.

Abstract: A cylinder block of an internal combustion engine, and in particular of a Harley-Davidson motorcycle engine, including improved sealing between the block and a secured cylinder head, and which is interchangeable with an original-equipment block. A nipple communicating with a fluid passage in the block protrudes from the block's top surface for being received by a fluid passage bore in the cylinder block head when the block end head are assembled, and sealing means is carried by the nipple for being received by and sealingly seating against the fluid passage bore in the head. The compression gasses from the cylinder bore are sealed off by a malleable annulus retained on the block's top surface about the cylinder bore and compressed between such surface and the head's bottom surface when the block is secured to the head.