Why Does My Harley Backfire Through The Carb

Stock is a lean #42. Hope we can get to the. Stock CV carb and Harley ignition, open air filter and 2 into 1 pipe with HP power baffle. 4) Repair as necessary. If you haven't checked the EGR valve in the last two or three years, do so now. , while the engine is running or while shutting down. It is not catching. Any suggestions. king did this after about 15,000 miles, shops said it was normal and I needed to change my riding habits. I had the same problem on my Kohler Command 16 on my simplicity. They can get carboned up if the bike has been coughing. Sounds like you have 2 different problems 1) the fuel backfire (intake)2) backfire after closing the throttle at speed (exhaust pipe). then you might be interested in my killer performance tuned cv carbs. This is where it could get tricky and most people lose their love for rejetting. Intake manifold air leak: A common and continuing problem with Harley engines is air leaks around the junction of the manifold and the cylinder heads. My question is, when you lift off the throttle does the Atomic cut off fuel? Or does it allow some fuel into the engine to keep the mixture from going too lean?. i bought this as a chopper project with engine and frame and stuff but never had it running, i did check the timing and cams. In the article he stated the rear metering plate used in a 4160/4175 model carbs (as well as some of the outboard Tri Power and Six Pack carbs) has a metering block. Checking an cleaning the carb shouldn't cost you anything, so I would still start therer. Hey guys, this is my first post on this site. Only other time backfire/ popping through the carb is if the dist. Enforcer suggested a sync and this is a very good suggestion, as most problems like this are related to the carb sync. The M and Super M Farmalls were known for loud backfires if you cut the throttle while slowing down from full raod speed, kinda neat really. This after-fire is a by-product of backfiring through the exhaust, something that was a common sight in older car models. When I drove it around the yard, it was fine through the mid-range, but as it reached higher RPM's, it fell off a bit and backfired through the exhaust a couple times. Does it do it under light acceleration as well? Timing retarded or advanced too far can give similar symptoms to what you have. 0 mph mercruiser I/O and ran out of gas. Do you think the same fix would work on a Husqvarna GTH2254XP lawn tractor with a FH641V and a Nikki carb? The carb does not seem to have a screw on top with a hole. Some coils are as cheap as $75 while others cost in the $300 range. if you can open the carb,you can start the block,dont let it die,and do a cleaner @ home job. I learned how to control my muffled back-fire flame emitting from the stock-style muffler tip, which was caused by cold air venting through my wear reduced diameter of panhead exhaust spigots. If the car has been setting for a while, the carburetor float valve may be sticking. By continuing to use this site you consent to the use of cookies on your device as described in our cookie policy unless you have disabled them. The carburetor of your mower engine combines fuel and air to make a combustion. and such(it all started when i putted on a set of world windsor jr heads. It is normal for many high performance exhaust systems to moderately backfire or pop when the throttle is closed from mid-to-high rpm. this link Performance Mods Section. When I got my Norton it would idle just fine and run wide open, but it stumbled horribly just off idle and would top out at 5,000rpm. Before I jump to that conclusion, I have to assume that by backfiring you mean spitting back through the carburetor. I went down this past weekend and here is what happened. Use the following suggestions to pin down your problem areas so that you can stop your motorcycle from backfiring. What are the most common causes and cures for this problem on a fuel injected twin cam motorcycle? From Our Friends at DynoJet Popping on deceleration is due to unburnt fuel being ignited in the exhaust. I have tried out a new carburetor also. Re: outboard backfire/fireing help please sorry. Afterfire occurs after the engine has been shut off. Terms often used are: Stuttering Hesitating Running Rough etc etc. And worse, many claims of lean conditions and rich conditions are contradictory. I milked it over the summer and figured I would look into it over the winter. when idling the engine down, or after the engine has been shut off. Watch the video at the bottom to see a backfire taking place through the intake manifold, possibly from a vacuum leak. Feels like a chain brake is on, and I've tried various carb settings with no success. I bought my boat last year and was never able to get the boat over 30mph which is when it would backfire through the carb. I pulled the valve cover and its seems like the exhaust side has either gotten really hot and burnt oil to it or maybe has some blow by through the valve guides im not sure but they are functioning properly nothing just stands out. Somehow the 2 stroke engine on my strimmer is backfiring when i start it, i pull the handle, it turns over and fires three or four times then something goes wrong and it starts flamethrowing, it does this all the way upp to 75% throttle and as soon as i lift my finger off the trigger it makes a huge explosion and stops dead. But, it would not rev cleanly, and was backfiring through the exhaust. the tank has got it spot on,its most likely air being drawn in to the exhaust through a pin hole or a loose seam but not big enough to cause a noticable exhaust blow. That will cover the idea that the rockers are too tight. Backfires are always accompanied by a loud, popping sound and many a times with a visible flame, referred to as the after-fire. Logged old age and treachery will always overcome youth and enthusiasm. Wondering if anyone has had any issues with backfires via the carb. You have no items in your shopping cart. This never happened before, there are also three new parts in the generator: the starter, the fuel pump, and the fuel pump--does this have anything to do with the backfire?. Start engine and run until slightly warm (about 1 to 2 minutes). Find answers to common small engine, troubleshooting & maintenance, DIY repair and parts questions throughout our FAQ section. Something loose? I took it to both of the Harley Dealers in my area and the first told me it was the jets and charged me $500 but that did not work, then I took it to the second and they rebuilt my carb and charged me $500 and that did not work. Engine starts and idles like a dream. Dry and white/tan might indicate a fuel delivery problem, black and sooty could be ignition failure or carburetor flooding. , but what you don’t understand is that it makes my life a pain in the ass – I’m the one that fields the calls and e-mails on why so-and-so wrote that and we know it’s wrong. The valves are adjusted too tight. ok, so my friend had my kz750b for a while and he couldnt figure out why i wasnt getting spark, turns out he was messing with the wireing on the points and the shaft it rides on, but now i figured out how to rewire it so im getting spark, but i cant for the life of me get it to start, all it does is backfire out the carbs, and sometimes the exhaust too depending on how i move the previously. Typical Rich Conditions. The stock engine from the factory has been jetted to provide the correct A/F ratio. Wondering if anyone has had any issues with backfires via the carb. Miscellaneous Carb Questions FAQ. There are some things you can do quick and easy to see if there are any changes. Keeping the fuel circulating back to the tank can keep the fuel and the carb cool. I suspect my PCV isnt working correctly. Also, what about the carb? Does it sound like it's toast, or is there a part I can look at/replace to get it running right again, as it did before the backfire. A back-fire or backfire is combustion or an explosion produced by a running internal combustion engine that occurs in the air intake system rather than inside the combustion chamber. A mower th at backfires is irritating, but thankfully backfiring is not a danger to your engine and lawn mower. Why does my sportster 883 backfire thru the carburater when the choke is off - Answered by a verified Motorcycle Mechanic We use cookies to give you the best possible experience on our website. If it is an exhaust valve, it will backfire through the tailpipe. It generally makes a loud sound, like a gunshot, and occasionally is accompanied by a visible flame. I bought it like it is and not sure if the Harley dealer tuned the. what can be the problem … Ran out of gas now won't start I was cruising around as a second day owner of a 2005 sea ray with 5. Ran a hose from the fuel pump to fresh fuel and it spits and sputters when you give it throttle and pops coming up through the carb. Why should an engine that has everything right still refuse to start. A backfire is back through the carb, a whole 'nuther problem related to timing issues. There is no sound at all of any ignition, (no brief starts, no backfire through the carb, no puff of smoke out the exhaust), just the steady grind of the starter motor. Unless your running a drag bike un-baffled pipes will make it run worse not better. briggs & stratton popping or backfiring through the carburetor Remove the valve cover and have a look, put up the engine's numbers, which are likely on or near the valve cover. 454 Backfires - Problem Identified Hello All - Newbie Here - wanting to share a recent find. Blip the throttle a time or two and observe the results. The document has moved here. when the engine was on the dyno it ran great and started up fine with very little backfiring thru the carb. backfiring through carbs. Next I'd have a look at the carburetor, take off the bowl and see if its all gummed up with crud, if so clean it. When the tank is low will it provide enough fuel pressure to keep it full at higher revs? My own Model A has a flathead V8 with the fuel pump on the engine so I cannot answer that question! What I will say is that we have guys running 97s on Harley D’s with no pump and the carb almost level with the tank. The 91 XR250R came with a #40 stock pilot jet and #125 main jet, Last year I tear my carb apart to clean it and found the previous owner had it jetted at a #45 Pilot and #145 Main. This never happened before, there are also three new parts in the generator: the starter, the fuel pump, and the fuel pump--does this have anything to do with the backfire?. If after resetting idle, one carb still appears to draw more air, you most likely have an internal engine problem. A hot muffler and gasoline with a high alcohol content may cause the engine to backfire, also. Is the popping gone? Does it backfire?. By continuing to use this site you consent to the use of cookies on your device as described in our cookie policy unless you have disabled them. all the settings are perfect. I have tried out a new carburetor also. Engine starts and idles like a dream. Why does my generator backfire then starts? I tried to start the generator twice with failure both times and then the third time after a backfire then the generator starts. Does your stock Harley cough and spit through the carb, especially when you pull away from a traffic light?. In order to truly tune my carb, I want a better understanding of the symptoms of lean vs the symptoms of rich. the left carb - will get rid of the backfire 2. I can get it to backfire through the carb in neutral by flooring it really quick. we alsohave carbs with cruse control linkage for road kings, road glide,etc. If I let the motor wind out just far enough and then was slow to release the clutch, and paused between shifts, I would get an impressive flame. A gunman approached Bernatchez after sneaking through a wooded area and spanning a creek in total darkness. Enforcer suggested a sync and this is a very good suggestion, as most problems like this are related to the carb sync. Does the backfire mean anything or is this normal when these engines don't start?. Researchers around the world working on ‘smart’ tattoos that can monitor health. We got it mostly gone, but every now and then it pops through the carb when you snap the throttle open. engine will also work on a 260 c. If you have any gumming in the carbs, you can have some backfiring and hesitation. So to find out what's wrong. If gap's okay but compression low, then maybe a leakdown test to confirm #3 intake valve is seating okay. If its still giving trouble, you might need to give the carb a good cleaning, which mostly sucks so because I'm lazy I'd try to run some barryman's b12 through it and see if that fixes it first. Help me understand why my 1915 Open Delivery occasionally backfires. So you want to get a little more power from your Harley-Davidson Sportster, but you’re not sure where to start. Re: Electra Glide Backfiring In my past experience, most cackling or as you guys call it popping, farting, and backfiring is usually caused by one of three situations. Why does my motorcycle backfire when turning it off? It could have to do with the fuel mix or your exhaust might not have enough back pressure, i. Then suddenly, my friend informed me that his harley just acting up and it backfiring and popping. The system becomes too rich due to the vacuum. Unburnt fuel that is ignited in the exhaust system can produce loud sounds even if flames are not present at the tailpipe. Usually after it has sat for a while or when I first start it in the morning. Edelbrock motorcycle carburetors. 1973 Honda Sl 350 Motorcycles for sale. Use the following suggestions to pin down your problem areas so that you can stop your motorcycle from backfiring. The engine was in a vk commodore that i brought but i have since swapped it into my '84 CJ-10 jeep. This is why I set my mixture screw half way between rich and lean stumble points. This after-fire is a by-product of backfiring through the exhaust, something that was a common sight in older car models. It doesn't run despite having a good spark, if I turn it over with a drill I get occasional backfiring, it is definately backfiring as the drill jerks and slows when it goes pop. Unburnt fuel that is ignited in the exhaust system can produce loud sounds even if flames are not present at the tailpipe. the scooter still backfires during deceleration. com/public/1zuke5y/q3m. It will keep popping, i will shift to 3rd if it does to see if a lower RPM cures the pop but it will still pop as i climb the hill. Please advise me on what the real symptoms of lean vs rich system is. Start engine and run until slightly warm (about 1 to 2 minutes). Carburetor Troubleshooting Guide. A support runs from the block bolted to and through the carb and intake manifold. Probable Solution to the "Firing on One Cylinder" Issue50MPH at WOT No More!. Intake manifold air leak: A common and continuing problem with Harley engines is air leaks around the junction of the manifold and the cylinder heads. Click to find 100+ Best Engine Backfire by Maurine Fadel such as Propane Jet Engine, Engine Backfire On Deceleration, Engine Backfires through Exhaust, Engine Piston Back Fire, Small Engine Back Fire Cause, Ford 300 Inline 6 Crate Engine, Engine Backfires through Carb, Model A Engine, Lawn Mower Engine Back Fire Causes, Pietenpol Airplane Engine, Car Backfire, Pistons Engines Back Fire Gifs. Hi, I have a Dewalt pressure washer 3100 psi. Or popping and spitting occurs through the pipe on deceleration with a closed throttle. My 02 electraglide. It seems like it might even be electrical at this point. What Causes a Backfire? When your engine back-fires it can do so in one of two ways. 1989 sportster 883. Backfiring can be caused by intermittent firing of the ignition system or very lean fuel mixture. If you're going to spit into nature's eye, expect to have your house knocked down. Find many great new & used options and get the best deals for Cobra Fi2000R EFI Controller #692-1600 Harley Davidson at the best online prices at eBay! Free shipping for many products!. David Pozzi is right about the backfire. I have a 98 Harley Heritage Custom with the 80CI EVO. It is a popping resonating sound generated by a lean condition on deceleration. The carburetor of your mower engine combines fuel and air to make a combustion. Note: Backfire and afterfire through the carburetor will not harm the engine at all! Find out the most common causes and possible fixes for engine backfire and afterfire. Any suggestions. Causes and Cures for Popping on Deceleration There’s a lot of discussion about popping on deceleration. Rejetting is a repetitive process in which jets are swapped in the carb until the desired A/F (air to fuel) ratio is obtained. Start set up by confirming carb base line settings. Why does my 2003 Fatboy cough and backfire through the carb? It only does it every so often. We usually refer to an exhaust backfire as a "backfire", and backfiring through the carb as "spitting" or "coughing". My sincerest Thank you again for restoring my faith in excellence and pride of workmanship. I can't figure out why my bike has began backfiring through the exhaust occasionally when I crank it. First, there is the real diaphragm - the one with the slide attached to it that the needle goes into. My first thought was that it was flooded, too. Understanding the Backfiring Mechanism. The carb had a much-modified 750 vacuum secondary that ultimately flowed about 920 cfm. this link Performance Mods Section. Terms often used are: Stuttering Hesitating Running Rough etc etc. It’s A Full Moon Tonight. If I had backfiring on my motor and the valves checked good, I would be purchasing another igniter. I'm getting spark to both cylinders, I feel good compression when I go to kick it, have adjusted timing. Solution: The source of this problem is often something other than the carburetor itself. International. Well at about 3,000 RPM's i'll get a slight backfire, or popping sound. when idling the engine down, or after the engine has been shut off. So, the popping you are hearing is not back-firing. super safe situation. If the pipes don't have enough baffle in them it will probably keep doing it. The performance may not be optimum due to signal strength or restrictions, but if the jetting is close for one, it will be close for the other. To get to the jets you will have to take the carburetor(s) off the engine. The thing is most cart engines are seriously detuned. Check out the best in Lawn Mowers with articles like How to Use a Voltmeter to Test a Coil for a Lawn Mower, The Purpose of a Welch Plug on a Lawn Mower, & more!. 1979 Sportster. I'm getting spark to both cylinders, I feel good compression when I go to kick it, have adjusted timing. Fuel usage is pretty much the same as is polution. the fuel was splashing back up the carb instead of pumping in and through. A great number of Harley mechanics reply that it is just something that must be dealt with in riding a Harley Sportster. It is a popping resonating sound generated by a lean condition on deceleration. Possibly damaged by a backfire condition. Hello Ken, I have a 2006 883 sportster and I recently replace the main jet to a 175, pilot jet to a 44 and added the EZ-Just Mixture Screw since I changed the stock air filter for a screamin eagle air cleaner and Vance & Hines shortshots pipes, the problem that the bike has is that every time that I ride for a long time gasoline will start leaking from the air filter so far I have cleaned the. It isn't actually backfiring, but when I shut off, a couple seconds after, it will do little ring a ding, bah bing, bah bing sounds, like I just tapped the throttle. 24lb injectors, 73mm mass air for 24's, 70 mm tbody and spacer, trickflow intake, msd ignition, blaster coil, ford racing wires, fairly new plugs none fouled, 10degress of timing, adj fpr, 255lph fuel pump, 42 lbs of. man did my riding skills improve!. It's a brand new out of the box carb. As you have probably noticed, tuning circuit operations are denoted in fractions of throttle openings. I can't figure out why my bike has began backfiring through the exhaust occasionally when I crank it. The only time i've had backfires through the carbs was when i change my intake to a crossover and one of the boots was not tight enough. This is the main reason why modified Harley engines tend to backfire through the carburetor more frequently than stock engines. Probable Solution to the "Firing on One Cylinder" Issue50MPH at WOT No More!. briggs & stratton popping or backfiring through the carburetor That backfiring through the carb could be an intake valve intermittently sticking. Is the popping gone? Does it backfire?. backfiring through carbs. The employee will be responsible vehicle scheduling, including picking-up/returning for all shop and video test vehicles, supporting, testing product installations and design of new products such as mufflers and exhaust systems, transmission shifters, differential covers, suspension components and other types of automotive related. The backfiring through the carburetor (the coughing or spitting), on the other hand, frequently happens in the morning when the carb's air/fuel mixture is too thin. hello all, learning more and more about this bike as time goes on. Turn RPM adjusting screw to obtain an idle speed of approx. Best Answer: A backfire like that is a lean burn condition. View my complete profile. The rapid burn that occurs while the exhaust valve is open causes a backfire. Carb, Coil, Anything to do with the Gen. So I'm having a weird kind of "pop" of air coming out of which I think is carb 3. OK, I'm at my wits end at this point. I suspect my PCV isnt working correctly. A backfire ignites the fuel, or something else flammable, outside of the cylinder where it should be ignited. Just let a high-rev valve float on an intake valve allow a manifold backfire and this is why many old time Weber tuners think of air filters as fire safety devices flame arrestors. I'm going to drive the car today and watch the AFR reading to determine whether it is going lean or rich when the exhaust pops. It didn't always do this. What Causes a Backfire? When your engine back-fires it can do so in one of two ways. It's back for the third time. pour gas - water - gas ,,,down the barrels & let her run out the fur ball. thanks mart. And maybe my 429 just doesn't like to be rev'd under load of climbing a hill. Did this occur after putting on the module?. I know how it should work, and this one seems funny. This is the main reason why modified Harley engines tend to backfire through the carburetor more frequently than stock engines. It doesn't run despite having a good spark, if I turn it over with a drill I get occasional backfiring, it is definately backfiring as the drill jerks and slows when it goes pop. getting a puff of air back through my #3 carbWhy does this happen? Possibly an issue with #3 intake valve seating. Re-mapping should help fix it. The backfiring of the motorcycle is a signal that something isn't quite right. My 68 shovelhead backfires through carb when trying to start very hard to get to fire but when it does turn on it - Harley Davidson Motorcycles question Search Fixya Press enter to search. Deceleration back-fire, rough idle, and throttle lag can be quickly adjusted by tuning your carburetor. any help is appreciated!!!. Then when I tried to start it,it backfired through the intake. Before I jump to that conclusion, I have to assume that by backfiring you mean spitting back through the carburetor. Terms often used are: Stuttering Hesitating Running Rough etc etc. If you run it up in neutral this doesn't happen. Please visit our support forum for post-purchase support of our products. Carb Engine backfires when I shut the car off ***Carbed Car*** [Archive] - DMCTalk Forum - A DeLorean Community. It doesn't run despite having a good spark, if I turn it over with a drill I get occasional backfiring, it is definately backfiring as the drill jerks and slows when it goes pop. It seems like it might even be electrical at this point. When the coil got hot it would spit and sputter and backfire. Typically, backfiring issues are caused by a timing issue, a worn cam lobe, or leaking valve. The fault is similar to the one shown by a carburetor with a faulty accelerator pump. Backfiring between shifts, and discovered, by trial and error, that enriching the mixture solved the problem. The bike definitely looks better, and the annoying backfire is GONE! Thanks! It's cool to see someone come up with a great, simple idea, and then produce an easy, inexpensive kit so that others can quickly implement your idea. 002 on the other. What is the difference between a 2:2 exhaust system and a 2:1 system and why does a 2:1 provide more power? Why do some aftermarket pipes backfire when you decelerate? How does the length and diameter of an exhaust effect sound? Do you have to take the complete exhaust system off to change slip-ons? What does a performance exhaust do?. When I got it, it had 3100 miles on it and I always had a problem with it popping through the carb. Have had it back to the installer 3 times. Sales for 1978 topped 17,000 units, the highest in Ironhead Sportster history. Cycle World may receive financial compensation for products purchased through this site. A number of new riders simply come to the conclusion that something is wrong with their bikes. The stock engine from the factory has been jetted to provide the correct A/F ratio. Fuel can not flow properly through a dirty carburetor; this will cause a lean-running engine. And people wonder why I practically run my cart through the car wash with those cleaning wipes […] The post It’s A Full Moon Tonight appeared first on People Of Walmart. I'm going to drive the car today and watch the AFR reading to determine whether it is going lean or rich when the exhaust pops. Find answers to common small engine, troubleshooting & maintenance, DIY repair and parts questions throughout our FAQ section. Do you think the same fix would work on a Husqvarna GTH2254XP lawn tractor with a FH641V and a Nikki carb? The carb does not seem to have a screw on top with a hole. I'll try again tomorrow after checking the plug. Possibly damaged by a backfire condition. Re-mapping should help fix it. this carb is a direct fit for all carbureted harley and buell models from 1988 to 2006. when idling the engine down, or after the engine has been shut off. We got it mostly gone, but every now and then it pops through the carb when you snap the throttle open. Power valve blown out by spitback up through carb. General Harley Davidson Chat - HELP!!! "coughing" or backfiring through the carb and intake! - i ride a 2003 Sportster 1200 custom anv. Check out some of my other blogs, I posted the rebuild of a couple Linkert M74-Bs. This is why a carb for a 454-V8 engine will also work on a 262-V6 engine. Help me understand why my 1915 Open Delivery occasionally backfires. If one of the carbs is pulling more oil through the clear tube than the other, either tighten the screw on that carb or loosen the screw on the other carb. , while the engine is running or while shutting down. My mother gave me a 1970 Olsdmobile Cutlass for my first car. Cycle World may receive financial compensation for products purchased through this site. 2 examples: I took the 600 cfm carb off my 390 truck and put it on my 4. The electric choke. When it does it during cranking, it's probably timing related. Note: Backfire and afterfire through the carburetor will not harm the engine at all! Find out the most common causes and possible fixes for engine backfire and afterfire. Replied by T-Rex in H-Town on topic Hard Start After Ignition Timing Usually, hard starting occurs when the ignition timing is too advanced, not retarded. I had the same problem on my Kohler Command 16 on my simplicity. My friend has a 16HP Kohler vertical shaft on his Craftsman lawn tractor that has started to do something odd that I'm hoping the experts here on Red Square have some ideas on. Loading Unsubscribe from HolleyPerformance? Cancel Unsubscribe. The mighty Harley is slowly loosing its carburetor. I can get it to backfire through the carb in neutral by flooring it really quick. The backpressure can cause backfiring and rough running and in some cases will prevent the engine from starting at all. I milked it over the summer and figured I would look into it over the winter. I have removed and cleaned all jets in the carb, put in a new piston and honed the bore, it has good compression, new correct specification spark plug. Troubleshooting - backfire through carburetor HolleyPerformance. - Popping or spitting through the carb occurs when the throttle is opened. In addition to their PWCs, Sea-Doo also produces various sport and speed boats. Shunning carbs causes the body to release the chemical β-hydroxybutyrate. Why Does My Engine Backfire Out the Muffler. A sniff of gas in t he carb is ano t her t ell-tale. , but what you don’t understand is that it makes my life a pain in the ass – I’m the one that fields the calls and e-mails on why so-and-so wrote that and we know it’s wrong. It does seem to leak a little gas out the accelerator pump gasket area. That about does it for the installation of all the engine components for the Sweet Tracker. It will clear out if I step on it and usually it backfires through the intake. Each time they say its fixed, but the next time we try to use it, back to the same problem. I must tell you though, that when the tractor was dropped off at my place, the engine cover, carb cover, and air filters had already been removed and were in a box on the seat. The air cleaner could stand with being replaced. 'Smart' tattoos that can give a warning sign if you're in danger of diabetes or cancer. Check out some of my other blogs, I posted the rebuild of a couple Linkert M74-Bs. We have a 8hp 2/s outboard that runs perfectly, ideling, forward and reverse gears. My buddys Harley is back at Chi Town Harley for the third time for the same thing. when idling the engine down, or after the engine has been shut off. Many Harley riders will likely be interested in why oil is leaking from the air cleaner in the first place. After Wide Open throttle runs my plug was showing black fluffly carbon indication a rich mixture but my bike still popped on decel. If your distributor took vacuum from the carburetor, you should probably just ignore it. Re: Is your 2-stroke BACKFIRING? This could help good to know did a rebuild and was at a loss for parts to replace with something major, was thinking a bad install but knew myself better than that. I had the same problem on my Kohler Command 16 on my simplicity. I have removed and cleaned all jets in the carb, put in a new piston and honed the bore, it has good compression, new correct specification spark plug. tape up anything ratty looking. The bike definitely looks better, and the annoying backfire is GONE! Thanks! It's cool to see someone come up with a great, simple idea, and then produce an easy, inexpensive kit so that others can quickly implement your idea. By continuing to use this site you consent to the use of cookies on your device as described in our cookie policy unless you have disabled them. Hey guys, this is my first post on this site. International. If you have a 600 CFM 4BBl carb on a true dual plane, the most any one cylinder can draw through the carb is 300CFM, where a single plane allows it to draw 600 (At its rated in. It will work in the KLR. Cranks over but sputters to get gas, check fuel line to carb, getiing gas to intake, tries to start blows blue smokes out exaust and backfires and stops trying to start. As others have mentioned I am assuming in my answer that you are talking about after-firing (like popping on deceleration). You did not send a model number, so I don't know if the information I am sending you will be helpful. The valves are adjusted too tight. the left carb - will get rid of the backfire 2. So to find out what's wrong. when the engine was on the dyno it ran great and started up fine with very little backfiring thru the carb. also there were no vaccuum pipes going to the carbs so i thought that was my problem, so if any1 knows where they go i would b grateful. It is backfiring through the manifold and has a hesitation off idle and through about 2000 rpm. I went down this past weekend and here is what happened. Next I'd have a look at the carburetor, take off the bowl and see if its all gummed up with crud, if so clean it. Yep, popping through the carb is USUALLY a lean situation. No more backfiring, though it's bogging and doing some sort of carb sucking sound under load between 1-3k rpms. Also, look at the float plunger, it could be hanging up and not letting fuel in the carb. Backfire I know it seems weird, but with the Kohler engines, you need to put it at half throttle (or maybe just a bit more) wait 15 seconds, then shut it down. Note: Backfire and afterfire through the carburetor will not harm the engine at all! Find out the most common causes and possible fixes for engine backfire and afterfire. It's also only likely to cause a backfire when cold. if you can open the carb,you can start the block,dont let it die,and do a cleaner @ home job. A gunman approached Bernatchez after sneaking through a wooded area and spanning a creek in total darkness. There are very few things as cool as a vintage dirt bike. Backfire in engines is caused by simple chemical malfunctions that can be easily rectified. 5k but smoothes out and has good power after that. He then played around with the adjustable idle mixture dial on the Mikuni carb until everything was running tip-top. Second, there is a small diaphragm that works on a costing. this link Performance Mods Section. If you have this problem, try priming the carburetor by using an eyedropper and filling the carburetor bowl through the bowl vent prior to cranking the engine.