oil in the exhaust pipe 79 gs850g

[850gs79]

I looked around the web but could not find a answer. I get oil in the end of my exhaust pipe, not alot. the bike does not smoke and the cylinder does not fire couse there seems to be a little oil on the plug. Some times it will fire when riding. The bike is a 1979 GS 850G. any help will be greatly welcomed.

[azr]

Are they new spark plugs? if not put some new ones in. Are you sure it's oil and not gas. Be sure of that first. If it's oil, it's probably your valve seals. Have you checked the compression on the bike yet? if not you probably should, it'll help diagnose these issues. As for the oil in your exhaust pipe, is it oil, or just black water?

[850gs79]

if i hold my thumb over the spark plug holeit doesnt build presure like the other side did when i did it. i will have to find a pressure checker to be sure but im beting it doesnt hold or is very little.