previously encountered unstable idle and found oil leaking from the carb 'neck' fitting into the engine.
upon close inspection after removing the carb; found a small tear on the carb neck O ring, replaced with a new O ring and refitted carb to try again.
now there's no oil seen at the carb neck area after a few hard runs and idle is ok now. temps at about 270F.
however noticed that there's oil on the LSN rubber sleeve. what's the possible cause?