trapperb1;
Some 2 piece pipes are held together at the expansion chamber with springs (three usually).

My Paul Turner midrange, and my friends Paul Turner high rev pipe both are held together with springs at the expansion chamber.

I think this is what he is talking about.

I also have an LRD midrange pipe that bolts together at the expansion chamber.

 

I know what you mean, 2fun, but isn't there at least one "bolt on" mount on the expansion chamber on almost every pipe? That's what I mean. I'm not trying to be contrary here, just trying to understand what's happening. He may be able to blow the expansion chamber off of the head-pipe, but I'm thinking that if he had all the bolts on it would tend to hold it in place. I'm still trying to figure out just where it's coming apart. Still, it's a big mechanical problem that's causing this.

 

Fixed the backfire it was the carb tuning. the pipe was coming apart at the joint in the expansion chamber only the back half of the pipe bolts to the frame that stayed in place . the front half was blowing off the flange and at the joint in the two piece pipe

 

My R did this twice in one day this winter. I was running a little rich with my Sparks TT pipe. It backfired and blew the pipe off the exhaust flange and came apart where the 2 pipe pieces meet.
After leaning out my mixture and a new plug, it was fine.
ERIC