My Thunder Tiger mufflers keep shearing the threaded rod. I have tried reinforcing with JB weld, loosening the lock nuts, tightening the lock nuts, tig welding etc. When I went to the last Tiger Stick contest I looked around and saw multiple airplanes with modifications to their Thunder Tiger mufflers. It seems that this is a cronic problem (loss of back half of muffler in flight). When I approached Ace Distributors about the problem they said that no one else has complained. How could this be? Our club alone has enough front halfs to go into production (if we could just find our back halfs). Everyone is giving up and buying Tower Hobbies mufflers. The problem is that the competitions we attend require a stock muffler. Please help me collect data or take it upon yourself to contact ACE and convince them that the muffler needs reengineering.