JB weld?, Epoxy?, I have a bisson muffler for a OS .46 fx and OS 1.60. Just put one pipe in a vice and crimp it closed.
It works great. no more fuel problems. This is a tip from an article.


Important note: On this setup I had to crimp one exhaust tube on the Bisson Pitts muffler in order to get adequate muffler pressure. Without this I could not get the motor to richen up at all. Once crimped it ran perfect.

This quote is from a review from RCUniverse by Mark Vigod when reviewing the Extra 300 1.60 arf by Great Planes.