APE developed this style of starter plate for the very high horsepower bikes that were experiencing left side crank throw failure.
This plate carries a bearing on the outside of the plate to give the crank support out on the very end. This prevents the crank snout oscillation that fatigues and eventually causes the destruction of the left side throw, causing catastrophic engine failure.
Complete kit comes completely assembled including our unique o'ring seal holder behind the bearing for leakproof operation. Aluminum starter nut that fits inside the bearing.
Note...The left end of the crankshaft must run true within .005" T.I.R. to use this setup. Cranks that run out more than that will tend to bind up with the outer bearing installed.