my car back fires and it blew up the muffler and i don't know what to do to make it stop. Can anybody help me.

 

What year, is it a stock setup etc. A common cause of backfires is bad timing and too much fuel. Sorry to hear about your muffler, those are not cheap for our cars.

 

sounds normal to me!

rotarys are prone to backfiring...but if your car is totally stock it shouldnt be backfiring that much. As above stated you can be running rich or timing is off.

 

first, it's not normal.
Second the most usual cause is a hole (even a VERY small one) in your exhaust system. If there is a hole in the exhaust, it will allow fresh air in and cause the explosion.
It can be timing, but unless you have messed with the timing, it won't change by itself.

 

its an 1980 and everything is stock. i will check up on the timing and the fuel how would you lean it up?

 

You should not have to lean it out. It should be fine. Unless your carb is flooding.

Check for small leaks in the exhaust system first.
And again, if you haven't touched your timing, then it should be ok. It won't hurt to check it. But, if it is on, don't mess with it.

 

mine backfired all the time and once I got a new exhaust it all went away. Like above, check for exhaust leaks

 

lucky.

 

Your running super rich! Are you running a cat? If not, could be a big reason. Mine backfires, but not enough to blow up the muffler.

 

Ok thanks for the advice i have fixed it i ran a new whole exhaust from the header back. and it purrs like a kitten it sounds awesome. very nice sound especially when
accelerating.

 

congrats! Annnnnnnnd check the timing anyway....