I also had exhaust leaks. I installed longer bolts (4) holding the muffler and muffler hangers. This allows using lock nuts on the welded blind nuts to let the muffler pivot at both points to minimize over stretching the springs from the rigid mounting. Most motorcycle exhaust use rubber grommets after the springs to accomplish this. After over a year and 800 miles this had worked so far. I've had good luck so far with my Z 800 trail. Hope this helps someone.