Exhaust backfire on deceleration I've heard that going to an expensive exhaust like Reinharts May 18, 2019 · To stop a car from backfiring, you should ensure the fuel-to-air ratio is correct, the ignition system is functioning properly, the engine timing is accurate, and the exhaust system is not malfunctioning. This is most noticeable when running above 35 mph and then completely turning down the throttle as I often do when preparing for a stop. Jul 27, 2014 · Ive searched for answers and have checked everything ive read. Apr 25, 2025 · “What causes backfire through exhaust?” is a frequent inquiry with many answers. Strong Smell & Smoke From The Exhaust? Is Backfiring Bad for My Motorcycle & Can It Damage The Engine? Is Motorcycle Exhaust Popping (Decel Pop) Bad? How To Fix & Prevent Motorcycle Backfire? Motorcycle Backfire FAQ What Is The Difference Between Misfire And Feb 19, 2004 · I have a 04 Fatboy injected with Air cleaner upgrade and SE II's and when I let off the gas I get a pop or backfire through the exhaust. Apr 18, 2023 · What does it mean if your motorcycle pops on decel or backfires? We explore the causes of decel pop and backfire and explain whether or not it's bad for your bike. Jun 4, 2007 · If the noise is more of a "burbling" than a "popping" it is from exhaust reversion, a resonance in the open exhaust system induced by throttle closure. Jul 12, 2014 · No popping or backfire on acceleration or deceleration. An open exhaust allows additional air to be “sucked up the pipe” during closed throttle and any unburned fuels, then ignite and “snap/crackle/pop”! The cure is the engine either needs to turn Jan 31, 2024 · Is your motorcycle exhaust making a gunshot sound or backfiring when decelerating? It’s bad for your motorcycle engine and environment. So give it a try and test the results. In addition, the carburetor was rejetted, bill indicates a #1048 jet installed along with a K&N High Flow TC88 Air Filter. Oct 25, 2006 · Ever since i put the O/R H pipe on my car if i rev the car up on the deceleration the exhaust pops/cackles. I found a couple of issues and have fixed those and now I get the backfiring/missing only after hard acceleration. It's common to feed them a bit more fuel and increase idle speed to remedy backfire. - If all the slides don't close evenly, some cylinders may get more fuel than others and pass that charge unburned into the exhaust. Oct 8, 2012 · My 97 400 Foreman backfires once very loudly when you back off the throttle at higher rpm's. On short open exhaust, many times you'll see a flame exit the exhaust along with the backfire. You do not hear this on a bike with a stock exhaust due to baffling of the exhaust. May 26, 2017 · Classified ads, photos, shows, links, forums, and technical information for the Volkswagen automobile Jul 10, 2025 · Upon encountering a backfiring problem, it is paramount to engage in thorough troubleshooting to pinpoint the underlying cause. As already mentioned set the idle speed at 1600 RPM, set the idle mixture slightly richer than ideal. #21 Backfiring On Deceleration Hello Group, One of the most asked questions pertaing to the Honda Elite CH 150/250 and CN 250 Helix involves a backfire through the exhaust on sudden deceleration. But when Dec 6, 2004 · Deceleration Backfire is caused by fuel burning in the exhaust manifold or header. Oct 10, 2015 · Exhaust backfire on deceleration Try setting PV to 19 and see if it improves. The only time I'm getting it is Decel popping, i. While riding bike, exhaust backfires/pops when letting off of the throttle in any gear The Deceleration Pop Problem Decel Pop is many times a nasty issue to deal with. The truck gets some backlash out of both sides on decel but also gives a strong backfire out of the exhaust when I let the throttle snap shut to shift or slow down. Any help would be greatly appreciated. But first things first, lets define the issue: Deceleration Backfire is caused by fuel burning in the exhaust manifold or What is this exhaust popping during motorcycle deceleration? These are some of the questions that may pop into one’s mind. Seems to be mostly on the left bank. But the bigger question is how does gas get there in the first place, and that’s a bit more complicated. It is not burning of unused fuel, which produces more of a pop and backfire. Exhaust leak / air getting sucked in on decel/engine braking when the throttle butterflies are closed = backfiring It's that simple. Oct 14, 2022 · What Causes Exhaust Popping on Deceleration? Popping on deceleration can be caused by both lean or rich Air-to-Fuel mixtures. The shorter the length of the exhaust pipe and the larger its opening, the higher the air flowing in the exhaust. Any ideas? thanks. Sep 23, 2022 · Six methods stand out for how to make a car backfire: exhaust modifications, ECU tune, anti-lag system, ignition timing ECU, old school on-off switch, and the Sep 22, 2008 · I am experiencing LOTS of backfiring through the exhaust when I am decelerating from high rpm (from 5,000 to 2,500). Oct 17, 2024 · Exhaust backfires on deceleration occur when unburnt fuel ignites in the exhaust system, creating the distinctive sound. But I have to wonder, as heavy as the Huracan exhausts are, can they Oct 13, 2012 · Exhaust backfire on deceleration - normal or not? Jump to Latest 13K views 16 replies 11 participants last post by philjonestaffy Jan 29, 2013 S Troubleshoot motorcycle backfiring with expert insights. I've heard people say that it's unburnt fuel burning in the exhaust which would be a rich condition. Oct 12, 2023 · Table of Contents What Causes A Motorcycle To Pop on Deceleration? The decel pop, technically known as ‘deceleration popping’, occurs when unburned fuel escapes the combustion chamber and detonates in the exhaust pipe, particularly in high-flow exhausts that allow more fresh air to be pulled into the pipe. The most common reason for exhaust popping on deceleration is a lean condition. Backfiring during deceleration can be caused by several factors: Lean Fuel Mixture: If the carburetor is delivering too little fuel to the engine during deceleration, the air-fuel mixture becomes lean. Now, I get exhaust "popping" when decelerating. May 7, 2025 · Learn about motorcycle backfire causes plus how to fix motorcycle backfire on deceleration and acceleration with insights on our blog at West End Motorsports. A lean or rich condition can be a result of a vacuum leak, blown exhaust gaskets, or internal carburetor problems. Aug 16, 2013 · Popping/backfire through exhaust on deceleration Jump to Latest 67K views 34 replies 16 participants last post by 1ofAMillion+ Aug 3, 2022 buening Discussion starter Jan 13, 2025 · Greetings everyone. And if it does, it’s quite natural for those of you who have interest in motorcycles that entertain in particular or for an owner rider worried about his/her machine. If you have aftermarket exhaust it can be tuned to eliminate all or most of your popping. I cant seem to get rid of the popping out the exhaust on deceleration. I have mine set at 16 right now for the same issue and that fixed it. This comprehensive guide will elucidate the typical causes of car backfiring and furnish actionable steps towards rectification. Aug 24, 2019 · It has been a great motorcycle and seems to run very well. Jun 30, 2013 · This article is written for those of you having problems with exhaust decel popping. Stick your head under the engine with it running and listen for any slight blowing. Motorcycle Backfire On Deceleration? 2. Unlike EFI, a carb can provide unwanted rich or lean mixtures at various engine loading and this is something we have to tune out. If I keep the throttle from completely closing all the way it doesn't do it. If I get on it pretty good, almost immediately feel it start to miss and as soon as I push in the clutch/decelerate get the exhaust backfire. The prior owner installed a Vance & Hines exhaust. When the exhaust leaves the cylinder, it is still burning air and fuel as it passes through the exhaust. Apr 13, 2012 · Deceleration Backfire is caused by fuel burning in the exhaust manifold or header. Sep 29, 2009 · Exhaust backfire on deceleration Engine & DrivetrainAll times are GMT -4. Most importantly, you must have a clear idea about motorcycle popping on deceleration: causes and solutions. Common Causes of Popping on Deceleration Several factors contribute to the occurrence of popping sounds during deceleration, predominantly revolving around engine tuning and exhaust configurations. The time now is 02:22 AM. . My only complaint is the popping and backfire on deceleration. Oct 19, 2023 · When it comes to backfiring on deceleration, the bike typically backfires through the exhaust pipes. So it turned out my BBC needed 18* initial, 20* mechanical (all in @ 3000 rpm) and 14* @ 12 hg while using 74 primary jets ended up being the solution. I'm about to throw in the towel with this one. (Carb Jul 22, 2014 · This is done for EPA reasons. Mar 20, 2023 · The exhaust is a set of ceramic coated lake headers from Speedway with their baffles and turnouts. 7 Vortec, 233k miles, 5 speed. I'm getting the normal exhaust backlash I'd expect from short pipes but my driver side has a loud backfire out of the exhaust when I let the throttle snap shut to shift. Don't go too far as that will cause other idle problems. This, in turn allows some un-burnt fuel to get into the exhaust pipes. Heavy backfire usually starts when folks add a louder, higher flow exhaust. Jul 31, 2022 · I'm having a backfire issue I can't seem to solve on my brand new SP350/357 crate engine. Mar 19, 2008 · Found this also: "In general, backfiring on deceleration (as opposed to acceleration) is generally caused by a lean condition in the pilot circuit. exhaust popping during deceleration, is in fact a common phenomenon in motorcycles with high-flowing exhaust systems. May 28, 2020 · Its definitely either lean fuel mixture, or just as commonly a leak in the exhaust system causing it. Runs fine in every other aspect. If your bike has stock exhaust and backfires it should be able to tune out your popping. When im shifting the drop in rpm's between shift makes the same effect occur. What happens is that the mixture leans out enough to where is fails to ignite consistently. The smallest leak can take in fresh air which promotes decel backfires. In theory, when unburnt fuel is combusted in say What Exactly Is That Popping Sound? When your exhaust makes those distinctive popping or banging sounds (technically called “afterfire” or “backfire”), you’re hearing small explosions happening outside your engine’s combustion chambers. These are things you can do or check to help solve this problem outside of just desmogging the motor. In extreme cases, backfiring can lead to damage in the exhaust system, making it critical for riders to differentiate between the two. Just tightening the header nuts now may be enough to eliminate most of the popping. Any time the exhaust is “opened up” the condition of deceleration pops is MUCH more noticeable and problematic. Jan 24, 2015 · Hopefully someone else DESPERATE to get rid of an annoying backfire on exhaust will someday find this thread and read the diagnostic procedure, as evidently they don't teach it to factory techs. Jul 20, 2008 · 1997 Road King, stock engine, 2-into-1 DG exhaust, HD airbox kit, rejetted original carb, 24,000 miles on bike. I have a 2000 C2500, 5. The physics behind this is actually quite simple. The PO, who was the second owner, said the first owner put a set of pipes on it, but thought it was otherwise completely stock. At idle, have someone hold a bath towel tightly over your tailpipe and listen closely to the rest of the exhaust system for leaks. The factory exhaust was way too quiet and I absolutely love everything about the race exhaust. Learn causes and solutions for exhaust issues. Feb 23, 2022 · With the amount of deceleration pop/ afterburn you are experiencing there is likely an issue with the exhaust install. Inspect the exhaust gasses, exhaust valve, and intake leak for issues, and consider a slight fuel adjustment. Check out how easy it is to tune your carbs to eliminate deceleration backfire. Apr 17, 2003 · Had the stock exhaust on my 03 FLHR Road King replaced with the Samson Silver Bullet 29" tapered muffler for RK models. Dec 5, 2008 · Deceleration Backfire is caused by fuel burning in the exhaust manifold or header. What causes this? My muffler is not packed and has no baffles. e. Some are very subtle others are very loud, but there are many each time I decelerate. Free Maintenance course Join my FREE maintenance course to achieve quality Jun 25, 2024 · If you hear a popping or cracking sound coming from your Harley motorcycle, more than likely it's backfiring. Motorcycle Backfire On Acceleration? 3. I noticed on reductions, when I'm using engine braking or decelerating that there's some backfiring in the exhaust. Jul 2, 2021 · Exhaust 'popping' on deceleration Jump to Latest 5. It is nothing to worry about. It runs well ,stable idle,good throttle response. I have a spec. Which can occur from multiple stimulus. Just keep reducing it by 1% to 16 until the popping goes away. No ifs ands or buts, that’s what causes it. When fuel is cut, it causes the exhaust burn to lean out and pop or backfire to to the leaner conditions. These however don't stop the fuel cut. Aug 10, 2023 · 1. The unburned fuel is ignited in the hot exhaust, typically in the header or collector. -timing is 18btc (doesnt improve when altered) -dwell is 31 -ive sprayed carb cleaner around possible vac leaks (no dice) -no exhaust leak -ive richened the idle mix screw and leaned it (no better) -carbs are synched (idles Feb 5, 2022 · Hi Mat. 8K views 15 replies 9 participants last post by done Jul 9, 2021 B Sep 15, 2005 · The popping on decel is likely from accumulated fuel in the exhaust system lighting off. It is possible to have an over-rich mixture Nov 26, 2024 · Backfire on Deceleration: This often indicates a lean fuel mixture or air leaks in the exhaust system. Our cams are similar. Then when the engine does fire, these un-burnt gasses are ignited in the exhaust pipe Jan 8, 2008 · Popping out the exhaust on decel is almost always a lean condition that occurs when the throttle is slammed closed at elevated engine rpm. Most people end up with some sort of fuel control or FMS. No exhaust leak I can see. occasionally from the passenger side. Optimize performance with our guide. If Feb 23, 2017 · If it runs fine bar the backfire on deceleration, its usually the exhaust side, or sometimes if the heads are not sealing properly to the barrels it can cause it. Popping on deceleration is due to unburnt fuel ignited in the exhaust. Jun 7, 2010 · On downshifting and deceleration, I'm getting a lot of popping through the exhaust pipes. - Leaks in the exhaust system can provide oxygen to enable the unburnt fuel to ignite with an ember from the piston chamber. One thing a lot of motorcycle owners don't realize is that there was probably decel popping with the OEM exhaust, but due Aug 28, 2023 · Popping on decel is common and normal. An engine is not supposed to backfire and, when it is persistent, It could be harmful to the engine. In the event of a backfire when accelerating, the Harley backfires through the motorcycle’s combustion chamber. Here are five reasons this is happening. Loud like a gunshot. Generally, there are a variety of ways it gets there, and a variety of things that can make the backfiring worse. This can lead to incomplete combustion and cause backfiring as unburnt fuel ignites in the exhaust system. I never have to pop or backfire during idle, cruising speeds, or under acceleration. It's long and I apologize, but I want to be as detailed as possible. While some drivers enjoy the occasional backfire for its sporty appeal, it could also indicate underlying issues with the engine or exhaust components. almost always from the driver side. Aug 11, 2013 · Re: Backfiring During Deceleration Here is where I am today. 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 -> -> Backfiring on Deceleration View original topic: Backfiring on Deceleration Sep 24, 2017 · The exhaust pops on my Huracan now literally sound like shotgun blasts since the factory race exhaust has been installed. Apr 26, 2009 · I notice that when I am accelerating if I let off the throttle, my exhaust backfires and pops. Yet, the most common reason for an exhaust backfire is an imbalance in the air-fuel ratio during combustion. What happens is that the cylinder mixture goes momentarily lean, you get a lean misfire on a few cylinders, and this misfire dumps unburned air/fuel into the exhaust where it then eventually ignites (explodes). So, why does a motorcycle backfire? A motorcycle backfire occurs due to incomplete combustion of air-fuel mixture into the engine cylinder or leakage in the cylinder valves Jul 24, 2015 · The popping is caused by unspent gas building up in the cylinder or within the exhaust header on decel and then finally the heat or spark will set it off. Not OEM gaskets but gaskets nonetheless. BTW MOST Cobra kits I have installed come with replacement gaskets. Is this normal or due to inferior pipes. Idle is 1500rpm. I have an exhaust backfire on engine deceleration, and a stumble when i get on the acceleration when It has a performance air filter (which I plan on replacing with the original filter soon) and a performance exhaust. You say the idle mixture screw has no effect. But there’s a kicker, and something you Oct 20, 2022 · Discover the answer to your burning what causes backfiring through the exhaust question with our in-depth guide. Yes, it is a "lean condition" but is not related to lean jetting. Acceleration is good and recent fuel economy check on round trip to Rolling Thunder was 47+ mpg. This topic generates a lot of concern from inexperienced riders, or even from experienced guys who just hate the noise, so lets take a look at what causes it. Jun 17, 2006 · Burn Baby Burn The last thing I want to address today is the subject of deceleration backfire, or “popping”. It has app 1800 miles and seems to be getting worse. Exhaust backfiring/misfire is a common issue many motorcyclists and car owners face. A couple things you can do. Popping in the exhaust while deceleration might be a minor issue, but still, you need to resolve this. qkkg lygv iwws igsqyx yqforru wgftnn awuat uqq otirk gqaii ueotbt tdbana vofjop penjj ehd