Worrying History

I have a 02 Polaris 550 f/c classic and have been prepping it for snow. When I came into this sled the previous owner was selling it for a steal for one reason or another. $300 with the only thing wrong with it, he claimed it needed a head gasket. He said he was running it last winter and while he was out he thought he saw some oil coming out from the head and he said it didn't want to accelerate. He "limped it home" and there it sat until I pulled it onto my trailer some months later. Since then I have been up and down this sled looking for a symptom of head gasket failure I have found nothing except that it needed a drive shaft bearing job. The bearings have sing been replaced and I thoroughly cleaned the engine compartment and surrounding area. Tonight has been a relatively cold night so I figured I’ll get it warmed and see if I can find a problem and even at ~170F it was running fine, no real issues. The only two things I found is that 1. It has a very low idle (probably ~200 rpm) and 2. Smoke comes out of the connection between the exhaust headers and the muffler. Not a lot of smoke but enough to notice upon closer inspection. I've found some oily residue at that connection and there is very very light oil coming out the end of the exhaust. Enough that after 15 minutes of idle I could feel a residue on the barn floor.

I want to be able to trust this sled going out on the trail, do any of these things set off a red flag or are this relatively common for any snowmobile?

Worrying History