Got a 2009 polaris xp 550 that I think has some major engineissues. I went to start it one morningand it wouldn’t start when I messed around and finally got it to start it isjust blowing black smoke and struggles to stay running it will not idle atall. I took the spark plug out and itlooked like it has oil on it so I took a flashlight and looked down thesparkplug hole and could see what looks like some oil on the piston. I’m thinking it probably has a bad valve butnot sure anybody had this happen?

 

I know the manual says 1000 hrs on valve adjustment,but have you checked them? .006 intake and exhaust.Could be the reason on the dark plug,plus the 550 and 850 were bad on fouling plugs,running rich if you even touched the throttle until it warmed up.

 

Its my 80 year old grandpas so im gonna say that the valves have never been checked so ill try and ajust them.