Pro Circuit exhaust leaking oil
 

Just bought a 1998 KDX 200 with a Pro Circuit pipe and silencer on it. It had a piece of oil soaked cloth zipped tied over the connection where the silencer connects to the pipe. I removed the cloth and the exhaust to see if there should be some type of gasket. Only found a 1/2 inch wide rubber ring on the outside of the connection - nothing inside. I tried a metal hode clamp on it, however, after a very short ride the connection still leaked gunk. Any ideas???

Sounds like you need to do some jetting work

clean with brake cleaner (or solvent), apply silicone.

and, of course, jetting.

Jetting, Repack the silencer and run Maxima SuperM at 32:1.:D

regardless of jetting, you will never totally eliminate spooge there if there is a leak.