Back Fire

[T.J.]

If anyone can help me out at M.D. at Don's this year. I would appreciate it.

 

I have an 04 MidNight with 81,000 miles on it that I cannot stop from "BackFiring". It use to throw flames out the back on hard riding decell and very loud. I have it tamed down a tad from that.

 

I have a CarbTune and have synched the carbs many times but still have a slight "BackFire"

 

Just asking because this is M.D and figured someone can help. I will bring the CarbTune and tools.

[gibvel]

How are the hoses and caps on the carbs? Do you have the stock exhaust?

[bongobobny]

Might be the AIS malfunctioning...

[T.J.]

How are the hoses and caps on the carbs? Do you have the stock exhaust?

 

 

I ran H.D. exhaust for 5 or 6 years maybe longer. Put stock back on to see if it helped with B.F. but did not. Hoses and caps look good to me.

 

Thanks

[T.J.]

Might be the AIS malfunctioning...

 

I plugged them in 06.

 

Thanks

[jakester]

I second the AIS... Air leaking from one of the caps or connections will do what you describe.

Good Luck

Bill

[cowpuc]

Get a bad gasket at one of the joints in the exhaust system so air can be drawn in and ya can end up with more booms and backfires than a good electrical storm,,, especially on a hard decell... Take a good look for leaks Teej..

[T.J.]

This is why I am asking for help at M.D.on Saturday. More eyes and ears to help out. I have checked and checked but cannot find anything.

[ragtop69gs]

I also plugged the ais but still get light popping on deceleration too.

 

Sent from my SM-N920V using Tapatalk

[Freebird]

There was an issue with quiet a few of these bikes where there was a bad weld on the back side of the exhaust. I'll have to show you where when you are here. If that is the case, a bit of JB Weld will usually solve the problem and it won't show at all.

[T.J.]

Puc doesn't even have to come to M.D. to help out but hope he makes it anyway. He made me think when he used the word "Gasket" I thought the only place there could be a "Gasket" was where the exhaust bolted to the head. Well after work I went out and started checking the bolts that bolt the exhaust to the head.

 

Started with the right side back exhaust. Got maybe 1/4 turn on both. Did not want to over tighten. Moved to the right front. Had to remove the front fin from the motor. Top bolt pretty tight bottom bolt was so loose I could turn it with Allen Wrench very very easy. Checked the left side. Had to remove the rear fin to get to the bolts. 1/2 turn same on front. Never would have thought of this. Thanks Puckster.

 

Hope this will take care of it. We shall see if it does on the way to M.D.

 

Thanks for all the input.:thumbsup2:

[videoarizona]

Also check the joint on exhaust before muffler.

 

My AIS is completely removed. Still some backfires... But with HD exhausts on ...I don't mind the pops... They blend well with the rumble!