I have went through three mufflers. Two stock and one TBM Silent beauty. All three broke at the down tube junction. Bob did send me a replacement right away after the first one broke. After the second one broke is when I bought the TBM muffler. After that broke I'm left beating my head against the wall trying to figure out why I can't keep a muffler on this engine. I have no problems or complaints about the engine itself. It runs great.