I have a 2011 Polaris 800 EFI engine which was purchased from a wrecker. While preparing to install it in my Sportsman, I noticed that there appears to be some small amount of oil residue in what would be the space behind the CVT backplate. It doesn't look like the leak is coming from between the shaft and the seal, but from between the case and the seal. These seals have a lip which sits in a groove in the case, so I'm surprised this could happen. Has anyone seen something like this before? I also that it could happen from spilling while adding oil if the oil ran down behind the CVT backplate and found it's way into this area on the engine.

I don't have any history on the engine, but it has good compression and less than 10% leakage, so I think it's going to run fine. I need to decide if I should tear it down to fix this apparent leak, or just get it one the machine and run it. Any thoughts are appreciated.

Oil residue on Polaris 800EFI PTO side.