DragBikeMike wrote on 09/05/22 at 14:56:39:Wow! That's some major axial movement. Thanks for the vid.
You have a very loose fit on your right-side main bearing. The right main bearing is a ball bearing. It controls the lateral movement of the crank. By design, the outer race is a heavy press fit into the crankcase, and the fit between the crankshaft and the inner race is a light drive fit. The crank is pinched to the inner race by the primary drive gear nut (Left-hand threads).
The movement shown in your video could be caused by a loose fit between the right-side main bearing outer race and the crankcase, or a loose fit between the inner race and crank combined with a loose primary drive nut.
Correction of either will require complete disassembly.
A mickey-mouse fix might be accomplished if the problem is related to the loose nut/loose inner race fit. Tighten the nut and sell it (pretty dirty trick).
Note that the normal crankshaft thrust is toward the right. That's true under both acceleration and deceleration. The crank always thrusts towards the right.
Unbelievable movement on yours. You also want to make sure that your cam drive sprocket on the crankshaft isn't shattered, and your balancer drive pin hasn't worked loose.
Thanx for the reply i just open it and the rigth bearing fits easy so you can move it, i think that they did a repair and insted of fresze the bearing to resamble they hit it so the case lost the ability to hold it, ill try to ensable using a bearing retaining compound as locktite i hoppe it works. The nut on the inner face was ok