85 250r....I have oil/gas in by the flywheel..

[boosted96cobra]

O.k. So I pulled off my flywheel cover and it had a little oil in the bottom of it. So I reached and felt the bottom, had a bit of oil in there. Smelled it...smeels like gas also. So is my crank seal leaking? The bike idles great, but was really hard to get jetted correctly and sometimes when I start it I get a bad backfire....would this explain both?

[Dirtcrasher]

Does the crank wiggle up and down just a hair also? You really have to grip it firm and it may have just a tiny bit, but usually the seals and bearings are 25 yrs old and should be done.....

You can also do a "leak down test" but being as to the design of a seal, I feel that forcing air through a seal from the crank helps it seal and may not always show a leak.

Most times you just have to say to yourself (honestly) how many hours are on this bottom end......

I try to do 1 lower end for every 2 or 3 top ends :D

[beets442]

+1 leak down and yes it sounds like the seal.Beets