Backfiring and Decel Pop — Is It Bad For Your Motorcycle? | The Shop Manual

As motorcyclists, our bike’s exhaust noise is a source of joy, pride, and… concern? People sometimes wonder whether decel pops and backfires are an exciting anomaly or something to be worried about. In this episode of The Shop Manual, Ari explores the difference between decel pop and backfires, and more importantly, explains which one is normal and which one means there’s something wrong with your motorcycle.

[justindavis]

Glad you mentioned the correct definition of "backfire". One real backfire can bring everything to a halt.

[chrisd]

I put a danmoto exhaust on my bandit, and the decel pops are amazing.

Roll down a hill with barely any throttle input and it goes popopopopopop the whole way down. Really makes my inner child smile.

[rwebiscool]

I JUST installed an aftermarket exhaust a few days ago and was surprised by the decel pops that began after. This video was timed perfectly as I was wondering if that was a normal thing! Thanks Ari!

[JeremiahHartmanPhotography]

Great video.. I think most people get decel pops confused with lean pops and worry unnecessarily. Back in the day with carbs and simple EFI systems when you'd put a new exhaust on it would lean out your mixture causing the bike to run super lean and pop on decel (which was bad back then).... newer bikes are popping because of what Ari was saying...from fresh air being injected into the hot exhaust gas...so it's totally fine now.

[RACE]

Bought my R1 already tuned, after 2 and a half years I've got my AIS (pops & bangs) turned back on. I don't see myself getting tired of them 😂

[G]

This video has put my mind at rest after installing a slip on to my bike. I was getting popping sounds and grumbling when rolling off the throttle. Thanks!

[Dexter-txfp]

Refreshing to see someone who knows what a backfire actually is. I love that he briefly mentioned off-throttle fueling as well. From the factory for emissions reasons, when you close the throttle completely you get whats known as decel fuel cut. When transitioning back to on the throttle and starting fueling abruptly again, this causes a harsh jerking transition. Any proper flash tune (not piggy-back trash like power commanders) can disable this. The downside (or upside depending on you) is angry demons releasing from your exhaust on decel, with potential for flames depending on your exhaust setup. The off to on throttle transition is 100 times better with this fuel cut disabled.

Side note, cars and trucks do this as well. Its not as noticeable of a transition as on a bike, but it still makes a wonderful difference when disabled.

[rickyrolls]

learned something new today, always thought that the they were the same thing, first time hearing the word decel pop in my entire life as well. I just installed an aftermarket pipe in my bike and some of my mates would tell me that my bike was backfiring, but thanks to this video i now know the diff of the two. great video as always!

[shogginr]

Rock solid basics, well done Ari! You have a knack for picking subjects that have needed clarification for decades!

[thedragonchatman]

I remember watching Ari Henning at the MC Garage when I got my GSXR 600 6 years ago. I just bought a brand new 2023 Vulcan S and now I'm taking his advice at the Shop Manuel. The advice from both the MC Garage and the Shop Manuel have kept me smooth as a rider. Thank you Ari.

[dusty]

I currently own a Buell XB12 and the decel pops are out of this world, i love it. Rolling downhill i get the constant pops and bangs. Got a real backfire twice which sounds way different (having the intake right under your chin so you can literally hear the engine breath makes it easy to tell the difference). The combination of a 1200cc V2 while accelerating and decel pop while letting go makes riding so much more enjoyable.
(Remus exhaust + K&N air intake are a nice combination)

[Kimsand]

Decel pop is cool, the first 10 times... After that it just became incredible annoying to listen to when commuting or touring.
It happend almost all the time on my Tracer 900 with an arrow exhaust that i got it tuned, way less decel pops and the bike ran much better.

[atem]

The CBR500R in the video is a perfect example of this. Bone stock they pop like crazy including mine because of the PAIR valves. Great video

[hexsymbol]

Thanks for this vid. I've gone from a leaky manifold that was causing backfires to a fresh full black widow system on my carb blackbird. But I have been noticing backfires when I'm rolling down the revs. After this vid I'm convinced it's audible decel pops as they're quiet and in line with the audio clip. Thanks for putting my mind at ease. Keep up the great vids

[D-Almighty]

I installed 2 Coffman shorty exhaust on my 2016 FJR1300 and the decel snap, crackle and pops sounds People be looking around like WTF and I LOVE #COFFMAN

[TheRealJohnMadden]

This video is really important for a lot of people, both car and motorcycle enthusiasts who love to do burble tunes just to get the "cool" backfires and flames from the exhaust. Probably one of the worst tunes you can ever do.

[desertfresh]

YES! BACK fire! It goes BACK through the intake. It's LARGELY a carb problem, but having your plug-wires or coil packs hooked up wrong can do it, too.

[billstadelman]

It's funny, because when I saw the headline, I just KNEW it was an opportunity for me to rip a new one into someone who, yet again, gets things wrong.

Alas, I temporarily forgot who I was watching.

What I really like most about your videos is that you get into the real detail of definitions, and you VERY APTLY explained the difference between a backfire and an afterfire.

It really is a hallmark of your Shop Manual Series of videos, and why I never hesitate to recommend them to friends. I know they'll get the best information.

Thank you!

[TheDetroitSlayer]

Ive had this argument with a few people. Youve also cleared up another argument Ive had about backfire and afterfire.

[joebaker]

My 2002 Bandit had custom ground jets and was tuned by reputable garage. It also had a high lift intake cam and a slip on. Carburetors can’t be tuned like fuel injection and thus I had lean areas and rich areas. My rich area was roughly 6.5-9k rpm. If the exhaust was warmed up and I rolled off the throttle from at or above the rich area of the rpm band, I would get decel pops into decel bangs. There was nothing wrong with my bike or the tuning. Only because it was carbureted.