backfire/popping on deceleration

Fiddy-one · 10-19-2005, 09:51 AM

anyone else have excessive popping and backfires on deceleration (sp?).
The bike runs excellent with a load on it, but when I come into a turn and let off the gas a little I get these nice little pops.
It looks kinda cool at dusk and nighttime since I get a 2 foot long blue flame coming out the back of the pipes, but I have a feeling I am burning up the packing in my canisters.
Could this have something to do with my Power Commander?
Any help would be greatly appreciated.

Thanks,
Drew

firefighter81 · 10-19-2005, 10:31 AM

100% normal, all bikes do it. Just extra unburnt fuel igniting in the can.

ApriliaSL · 10-19-2005, 10:37 AM

I'm sure you have some after market cans throwing your fueling off, my big twin did the same after I put cans on it they seem more prone to it with their big jugs than those with 4 smaller ones. You are likely too lean or rich, fit a power commander and remap your fueling.

ApriliaSL · 10-19-2005, 10:39 AM

Sorry I missed the PC you already have. Get a custom map it will take care of it and sync your TB ( throttle bodies)

Josh D · 10-19-2005, 11:22 PM

What pipes do you have, and which map is in your power commander?

joe mamma · 10-20-2005, 02:33 AM

I have an sp1 and when I put pipes on (w/o a power commander) it did this, it seemed to be running really rich. But after I put on a powercommander, it really smoothed up the throttle and stopped (80% of) the backfiring when I let off the throttle.

I'd check the map on the pc.

randyrandy77 · 10-20-2005, 02:40 AM

it is normal especially with aftermarket pipes. the baffles in stock pipes dont allow the flames that are present in the stock cans to escape they burn out before they exit. aftermarket cans are a straight shot and the nice little flame is normal. you may or may not be burning the packing but i wouldnt stress it too much. and you arent hurting the bike at all like the other guy said all bikes do it. normality.

ps my bike is 04' stock and i can hear throught the stock cans it does pop but no flame. if i put aftermarket pipes on it i will have the nice flame and popping too.

Fiddy-one · 10-20-2005, 08:01 AM

I do have two bros exhaust but it seems that this backfiring has increased in just the last two months.
I am going to get a re-map and TB sinc this weekend and see what happens.
Thanks for the help.

Jake · 10-20-2005, 04:03 PM

I've never had this problem on my RC51. I never remember it backfiring when stock, never after the Jaradine slip-ons were installed, and never even after I did the soft-rev, flapper valve, and pair valve mods.

Josh D · 10-22-2005, 02:20 AM

Have you done the pair mod? I was thinking that I read that the pair mod helped to reduce your problem, but I might be thinking of something else.

My experience is similar to Jake's. There was only 1 time when my bike started popping. A friend and I were going to eat at a place about an hour away. 1/2 way there, we ran into a traffic jam where a semi had turned over. The traffic, as you can imagine, was at a crawl pace, but just enough where you wouldn't want to have to push your bike. It was about 95 degrees, sunny, and humid. The bike started to get so hot that I couldn't sit on the seat for more than a minute or so. It wasn't overheating or anything, just getting really hot and making me sweat like a whore in church. We finally got turned around and about 5 min later, when going through a town, the bike started popping on decel. That is the 1 and only time to date that it has done that on me. BTW- I have Sato Banzai pipes and a PCIIIr with a great map. I'm pretty sure the map is set up fat, as it was made for lowrange-midrange smoothness, and not so much top end power.

G-Man · 12-06-2005, 08:42 PM

It's a common misconception that unspent fuel (often from a too rich mixture) is the cause of popping/backfiring on deceleration.

Although you have to have unspent fuel to ignite, the actual catalyst is additional air introduced to the exhaust stream after the initial combustion, either by the bike's PAIR system or by a exhaust joint that may not be completely sealed.

Eliminating the PAIR system should reduce the amount/frequency of backfiring on bikes with aftermarket exhausts and no Power Commander. The PAIR system should be eliminated prior to any Power Commander custom map development as well.