xr250 oil in chamber

[Spurs19]

I have a 92 xr 250 and was having a bit of trouble starting it so thought changing the plug might help me out a bit. On removing the spark plug it was black and oily. According to the haynes manual oil may be leaking into the chamber and the symptoms it lists are what I have been experiencing (hard to start, misfiring, hesitation). I want to try and sort this out myself but have little/no mechanical knowledge. I don't know where to begin, what to take apart, what to look for, what to change. Feel lost.

So any help, advice, links, words of encouragement would be greatly appreciated. Anyone else ever had this problem? How did you go about sorting it?

Thanks

[AIRWOLF]

Sound's like piston ring's and valve stem seals, . . . . suggest a top end overhaul, . . . maybe a rebore and piston. . . . . all the info to carry this out is in the haynes manual.

[StumpyFingers]

It could just be a worn out gasket.