ok.I looked at a 1983 rx7 today.When he got on it then let off it would backfire.stock everything on the car? carb need to be tuned?timing?

 

These cars tend to make a popping/backfiring sound when decelerating. You have any more information regarding the car, as far as why you'd think it'd be the carb or the timing?

 

dont really have any imformation.i jsut didnt know thats what these older rx7's do.I was just worried cuz its all stock and thought when i get exhuast and remove EGR probably gonna be a loud popping.
he said something aboutthe timing...uurrr...i cant remember..thats why i thought maybe that was it.i forget if he said it doesnt run as good with timing turned up.ill probably remember later.
thanks for the quick response!!!!!!!!!!!

 

Could be, and probably is a leak in the exhaust.

 

YOu will generally get a backfire on startup its just a RX7 thing at least a 1st gen thing. I had the hole in my exhaust fixed the same time i got my carb and timing all done so I wouldent know what was cauing mine but one of them or all of them fixed the back firing because i rarely backfire now.

 

I never had this w/ my stock 7 but did w/ the street ported after taching it up high in racing-then decelerating. I think you are dumping too much gas. Have your carb output checked. Replace spark plugs.

 

i have the same popping sound when i rev it up high and then let go of the gas....i think i have an exhaust leak somewhere too

 

I like fireballs.

 

My car does it on startup if I use the choke (gives off a pop or two every 30 sec), but doesn't if I don't use the choke. Also, when I rev to over 4000 rpm it gives one good loud pop and then a bunch of smaller pops while winding down. I brought it once to redline yesterday. When I let off, it gave one hell of a bang and then just a lot of smaller pops after that. This is just reving in the driveway. But I also have a straight through exhaust.

 

Is the backfiring during deceleration something that can cause harm? I've started to experience it in my SE... should I worry about it?
Also, how would one go about looking for exhaust leaks (and fixing them)?

 

Unless you start getting HUGE backfires all the time (not just a single bang under decelleration), it could potentially blow up your exhaust. But thats about the only thing that could happen.

Basically a backfire is the burning of unburnt gas in the exhaust system. So that makes sense now doesn't it.

 

So basically it also means that I'm running rich?

 

Well, thats basically it. But the thing with rotaries is that they tend to backfire a LOT more than piston engines. This is due to the short exhaust stroke of the engine and the extreme heat of the exhaust gasses. It forces more unburnt gas into the exhaust and since the heat is so great, it burns it. It is almost impossible to stop the backfiring on a rotary, unless you have a cat still.