Got a couple of crank seals from gasbike yesterday, only to discover that the ones they sent are not the ones I need. I seem to recall reading that the left and right crank seals are different, and either they are different from one another, or the left is different from the right. In any event, I have no crank seal. The size of the seal I'm replacing is 29x17x3.8. That's ODxIDxthickness, in millimeters. Motion Industries has a store near me (there's a big strip of factories they serve), so I stopped there with my old seal. I'm picking up a 29x17x5 today, which should be fine, and for only $5. I've dealt with them before on some other stuff, they've had great service.