On the TZ350C Svend Andersson, our Danish friend, welded new hooks for the exhaust retaining springs. On the TZ350G I glued the screws into the springs with Araldite and I secure the springs with narrow jubilee-type clips (8 mm). These are the clips Yamaha and the other japanese brands use for airfilter > carburator, etc.

Yamaha TZ muffler attachment