My bike is leaking oil from behind the chain sprocket. I can't find anything online showing a gasket behind. Anybody have a part number for the seal? It leaks pretty good and can clearly tell it's from where the shaft comes out of the crankcase 

Seal part number.  9310226042

Spacer part number. 90387202A0

You will likely need both the seal and spacer as one wears out the other and the spacer is likely rust pitted to boot.
 

Thank you for the part numbers

I've seen on some bikes, maybe a name we can't say here, but had a very thin Oring & the spacer had a small recess so the Oring compressed into there. It was to stop the possibility of oil finding its way along under the spacer. To my mind if the sprocket nut is tight & all faces being square on then no oil should be able to get out there.
Reminds me of the CB450 Twin we sold new & it had an adjustable oil feed on the end of the final drive shaft to oil the chain--i thought that was tricker than trick.
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