have the same issue with the exhaust- it is made to move in its socket as the lower end of the pipe has two isolation mounts (rubber) so it needs to move at both ends. a bit of oil leak is not going to stuff anything up. dont waste your money on a new pipe. we just welded mine up at the ball joint and made the isolation mounts solid so now the pipel actually vibrates iwth the engine which to me actually makes sense as now there will be no independent vibration of donk and pipe. a bit of oil is not a problem it is a two stroke. piston is only a single ring item by design. dont be tempted to much with oil % as you will seize it.
