I have an OS 120 FS and the exhaust thread to the exhaust arm is so loose that no matter how tight I tighten the nut, after some vibration, when the engine is on, the exhaust will work itself free. I have used some pipe sealant but it still comes loose. I am thinking of putting some hemp fibers on the thread and than screwing the exhaust to give a better grip. Will that work? Any advise appreciated.