ORIGINAL: on_your_six
I try to use socket head bolts to fasten the muffler to the engine. I drill a small hole through the head of the bolt and wire the muffler bolts together just like on full scale aircraft. I have never lost a muffler or bolt using this method and don't need any loctite.
The only trouble with this is some mufflers have recessed bolts and you can't get to the heads.
I have a little Chinese engine that has recessed bolts. I have tried every concoction made and the bolts wont stay in. I am going to have to buy longer bolts and spacers so that I can get the heads out where I can wire them.