Did Oil Get Past the Seals in My Yamaha Raptor 660?

If your Yamaha ATV blows out a puff of smoke the first time you fire it up after it sat for a while, is that something to be concerned about? Does it mean oil got past the seals?

Partzilla’s Yamaha ATV expert John Talley livestreams Q&A sessions on our YouTube channel every Friday at 3pm Eastern. In this session, John was asked if a 2004 Yamaha Raptor 660 blowing out a puff of smoke once after it sat too long is a problem with oil getting past the seals. 

Yamaha Raptor 660 Oil Seals Q&A

I have an 04 Yamaha Raptor 660 that sat for a while since the last ride. Starting up, it smoked a little but then the next time we rode it, there wasn’t any smoke. Do you think oil is getting past the seals from the valves?

John Talley: That’s a safe bet. I mean, it’s almost impossible for the oil to seep up past the rings. So more than likely from it sitting long enough, yes. I’ve seen this especially on some of my project cars that I let sit up for several months. Yes, it’s going to blow out smoke there for a few seconds but it’s nothing to really worry about, because it’s just pulling it right past those seals up on the valves. So, nothing to be concerned about, unless it goes on for 3 or 4 minutes. If so, then you may be heading toward a problem, but not if it’s just that initial puff of smoke and then it burns it off within a minute or so.  

Watch the video below to see our complete Yamaha Raptor ATV engine rebuild.  

Watch the video below to see how to adjust the valves on a Yamaha Raptor ATV.  

Watch the video below to learn about reasons why engines blow up.  

Want to see more live repair questions answered? See more motorcycle and ATV repair questions answered here.