This weekend my buddy and i were ridind some trails/homemade track and his pipe on his 250r (1987) kept blowing apart at the joints when he would have a backfire this happened about 8 times . This was the first ride out after a complete engine rebuild any help would be appreciated.

 

Make sure you are using the bolts to hold it in place, not just the springs. What kind of pipe is it? It would take a small nuclear explosive to blow my pipes apart. I've got an ESR trx6.

 

there is no place to bolt the pipe together only sprins maybe anyone could recomend a pipe to use?

 

First, he needs the fix the problem with the quad backfiring, that's not good. Second, exactly where is the pipe coming off, where the silencer mates up to the pipe or where the pipe connects to the exhaust flange. Springs hold the pipe to the exhaust flange and if you have a 2 piece pipe, I'm sure you do, springs also hold the 2 piece pipe together. The silencer is mounted to the frame, normally, so it should not be blowing off the pipe. More info needed please?
I run ESR pipe and silencer, excellent fit and finish and performance is outstanding!!

 

When I had my stock pipe on I blew that thing off. I was running a $h!tty plug and it kept causing it to backfire, as soon as I got home I changed the plug and never had a problem again. I also run an ESR pipe.

 

could it be a cracked head? in my old 72 nova when i cracked my head it blew my muffler right in half. i must say that was a embarrising ride home [img]i/expressions/face-icon-small-smile.gif[/img] the only other thing is maybe timing. to blow a pipe off i would figure one of these.

 

there is no timing on a 250R

 

sure there is, or the engine wouldn't run.

 

If the carburator is messed up, it can also cause a backfire.

My friends 250R did the same thing last time we went riding at the dunes.
KAPOW!! blew the pipe out of its sleeve (where the pipe slips together 2-piece).

Took three of us to pull on the remaining two springs to separate it and slide it back into the expansion chamber!

Never did it again after that though.

The wrong octane/bad gas can also cause a backfire occasionally.

Anything that doesn't allow the mixture to ignite at just the right moment can be cause for trouble.

Try this
Fresh fuel
Fresh plug
Proper jetting
Make sure you have a strong, consistent spark also.

 

OK, I'm trying to figure out where it's blowing off. Springs hold pipe to cylinder, next piece has one bolt-on mount and also springs to head pipe, silencer slips over pipe and silencer is bolted down. Are you leaving some bolts off???
Fix the backfiring problem. Shoot, a really badly mounted leaky pipe could cause backfire; it can suck cold air back in on top of the heated exhust coming out and cause problems.