However the seal works not on the crank drive shaft, but the distance piece fitted chamfered side in...if the oil seal is not slush to the crankcase outer but somewhat lower, it will still act on the distance piece...but too far in and the drive side bearing will chew it. Stick to the factory, on my original it's pegged at noon,3,6 &9 by punchmarks, but then I have the original steel backed oil seal still fitted.