Flames Out Exhaust Rich Or Lean







2014 - 2017 Harley Davidson Dyna Wide Glide. Now repeat with cylinder 4, 2 and 1. As well as the. On the other hand if you have lots of little bubbles in you castings when you machine them or polish them it is probably hydrogen from having a too rich flame. If the light throttle is satisfactory, trying going 1 stage lean in the Cruise Mode. You are getting backfires because you need a tune. Running rich is caused by different issues (some as simple as a dirty air filter). This is the bottom side of a 1985-1986E intake manifold. Having an air/fuel mixture rich enough for all racing conditions will allow you to get all the horsepower out of the engine while getting as many laps as possible from a tank of fuel without. When the mixture is too lean, it doesn't burn properly, so fuel goes into the exhaust and explodes there. However, lots of people are understandably worried about. Don't know if one exists, I've just heard about them. In less than 2000 miles one of the pipes had absolutely none left inside. For the petrol-heads or the speed junkies the condition might look tempting but in fact the rich mixture has also drawbacks as the Lean mixture has. Over 160,000 unique items in stock & ready to ship today. This may or may not be evident with a stock exhaust due to the baffles and converter but with the slip-on it would allow the straight path the ability for the gas causing flames to pass through and out the exhaust where it is burnt on the way out. Watlow manufactures industrial heaters, sensors, and controllers for a variety of applications. The wasted energy is measured and displayed on a triad of cockpit gauges: oil tempera-ture, cylinder head temperature, and exhaust gas temperature. This can turn the exhaust manifolds into cherries. All fluid levels has been monitored and they are stable and normal. d full exhaust. So take your time and don't get discouraged. or a cylinder not firing all the time or at the wrong time: unburnt fuel builds up in the pipe and then backfires when the stuff in the pipe actually ignites. How do you shoot blue flames out the tailpipe? run your engine extremely rich/lean? C. Explore millions of exclusive, royalty-free, stock photos, images, and videos. Your exhaust is scavenging gas air mixture out of the cylinders and then burning as quickly because it is interior the pipes. No foot long flame shooting out the exhaust today only a tiny flame inside the pipe on de-accel. tbi o2 sensor, header discussion PLEASE READ. It was repowered before I got it, and the P. This is a review of how I repacked my Vance & Hines Classic II slipon exhaust for the '94 and later Honda Magna. 1V (High Oxygen, Lean mixture) to 0. What heat range spark plugs are you running ? 3. A word on pipes. When its RICH, there is unburnt fuel thrown into to exhaust header. The lean mixture is slow to burn and there may be a bit still burning at the top of the exhaust stroke where there's a bit of overlap between the closing of the exhaust and opening of the intake, and the flame sets off the charge in the induction system. An oxygen sensor failure can lead to incorrect readings of exhaust gasses. I solved most of my fumes problems by sealing up the rear of the car w/ new gaskets & weatherstripping, and adding a longer exhaust tip. Jeff's Little Engine Service 347,018 views. Spark plugs produce the electrical spark that ignites the mixture of air and fuel in each cylinder of your engine. Dropping the primaries will give you that lean pop then it will take off when cruising, but fine from a dead stop. Unlike gas engines, diesels have no throttle to restrict airflow, so they're always pumping a full amount of air. I have a idea but its shabby right now. Now, I understand this can be either a lean or rich condition at throttle lift where un-burned fuel collects and ignites in the exhaust system. I am gitting ready to put a motorcrfat 2150 carb on but i need to passs emisions now wiht the carter carb on. 036 gap from the current. Search now. And, there is some oil residue around the engine, the guy said that was a sign it's running rich as well. Pull them out and check the inlet side. Therefore, the high EGT serves to heat the pipe more and the gases themselves become a much better source of re-ignition. We offer the best customer service in the industry!. Chrysler Electronic Lean-Burn. In the automotive industry this sensor is also called a UEGO (universal exhaust-gas oxygen) sensor. Possible Causes: Refer to our Oxygen Sensor Code Diagnosis article for a list of all possible causes. Rich Condition: The rich condition is a state where the mixture is comprises of more or excessive fuel and less air. The most important concept to understand is that lean mixtures, such as at idle and steady highway cruise, take longer to burn than rich mixtures; idle in particular, as. So it keeps burning all the way out the exhaust pipe. 2; for the latter, assume that in the exhaust, there are a moles of H 2 and 3a moles of CO. Step One: you want to take your screw and or nail and find a clean area on the interior of your exhaust tip about 2 to 3 inches deep. (air leaks for lean, leaking injectors for rich, or excess fuel pressure. backfiring - lean or rich? i'll be checking it out this coming weekend. It doesn't seem to smell like rotton eggs so I don't think its a head gasket issue. When this mass of unburned fuel hits the hot cats they ignite and shoot flames. exhaust temp to raise, running rich will. You can relate a to by elemental balance. The air to fuel ratios of lean-burn engines range from 20:1 to 50:1 and are typically higher than 24:1. ” Any calibration other than ideal …rich or lean will reduce the efficiency and power!. When adding an aftermarket exhaust, it is wise (and advisable) to rejet the carbs to increase the fuel delivery to match the much larger amount of air. my deuce is running just a little rich i'm not going though spark plugs like hot cakes or anything,just on the rich side i've adjusted the fuel mixture screw can't get it worked out i'm thinking its the jetting. I can't see how it can be lean. • Do not use aluminum foil to line any part. This storage usually occurs when the system is running lean; the gas is released when there is not enough oxygen in the exhaust stream. If the exhaust note rises and stays high till you drop the piston, this carburetor is adjusted too rich. Am I running rich or lean?. Turning screw in (clockwise) makes mixture leaner. Rich gas and lean gas are the two types of natural gas that are distributed in Belgium via different networks. A drop of water or spit on the engine heat immediately sizzles. (a fuel-rich flame) to obtain maximum response. backfiring - lean or rich? i'll be checking it out this coming weekend. What Causes Backfire? When the engine on your motorcycle has an emission system malfunction, such as an exhaust leak or a moment of running rich or running lean, backfire can occur. An exhaust backfire is either a leak: it lets the cylinder suck air back into the cylinder causing a lean condition. You may have also seen when too much oxygen is turned on, the flame goes out with a pop. It doesn't seem to smell like rotton eggs so I don't think its a head gasket issue. If the color is black the mixture is too rich. Far cheaper than buying the tuner and software. i then researched more and found out how. Flame Arrestor upgrade for 650 and 750 engines The stock 650 and 750 air intake flame arrestor is restrictive, and reduces engine power somewhat. a leak as far as 10in past the sensor can cause the sensor to read the outside reference air. Flames Coming Out Of My Headers Why I’m workin on my buddys 62 impala. This is because flames from the combustion can jump through an open exhaust valve and cause unburned fuel to explode in the exhaust system. 5 Reasons that Cause Your Car Backfire – Diagnosis and Troubleshooting which has an open exhaust valve, out of turn. While leaning on the ground, isn't it ok to lean while at run up RPM instead of full throttle? Got me thinking about that now. If there was more, it may be orange. If they're only lean at idle but operate normally while the engine is at cruise speed (~2000 RPM), then it's probably a vacuum leak. The ECM uses that information to adjust the fuel ratio to keep the engine. Thus I do NOT recommend using Superwool for exhaust repacking. That would cause poor valve sealing. Rich Condition: The rich condition is a state where the mixture is comprises of more or excessive fuel and less air. Black smoke is an indication that your air-fuel mixture is running rich. The computer uses the information from the 0 2 sensor to determine if more or less fuel should be added to the mix in order to maintain the correct proportion. Examples: Exhaust system leaks upstream or near HO2S, malfunctioning Secondary Air Injection system. In fact, just swapping out the stock filter element for a freer-flowing K&N one will sometimes give an engine a little case of the coughs off idle. This is how:. Unfortunately, when we have a rich or lean condition, we usually look for external engine problems first. Power is controlled by how much fuel is added to the mix. You just need the idle a little higher than normal so the bike won't die when you go in/lean. The computer uses the voltage to decide if the throttle is open and how far, so it can adjust the fuel mixture. So what causes it ? Heres a vid. This process happens continuously at high speed when the engine is running. Choose from an expansive collection of maps dyno tuned in-house by Vance & Hines. Rich being greater than 14. This opposite effect is caused moving the heat or the flame out of the chamber into the exhaust with a retarded ignition and raising the temperature of the EGT. It's much more intense when coming off of hard acceleration. If the plugs are too white, the operating mixture is lean, and, if lean enough, can cause problems. P0131, P0133, P0151, P0153. exhaust temp to raise, running rich will. If you notice a nasty smell from the exhaust, such as a rotten egg smell, then there is a problem. Whatever the problem is, recognizing when your engine is running lean is important for maintaining the health. Dies while accelerating from idle. The answer to after fire on carbuertor engines was good. Wires first, plugs, rotor and cap. With just a bit of know-how required, cooking on a charcoal grill pays dividends in delicious flavor. The exhaust valves are the ones most likely to lose their seal and leak compression, so, if you find unusually low compression, follow up with a wet compression test to determine if the problem lies with the valves or rings. If I ever think of it, I'll tweak the carb just a touch one of these days. Eventually, enough is there and it ignites due to the hot exhaust. Especially driving uphill, black smoke means the load mixture is too rich (turn in). The poor guy on the other end of the phone is giving me every intimate detail about his modified engine in hopes that I'll be able to rattle out the exact cause of his most recent piston seizure. Turn the mixture nut one flat (one-sixth of a turn) up, moving the jet toward the bridge, then repeat Step 4. I brought it to a mechanic for a safety inspection and asked him to have a quick look. There used to be a product on the market that would clean smelly cats; no idea what it was. After spending the day on the dyno Saturday, my 450 popped and shot flames out 4 inches after 11,000 rpm runs. The glow plug wire or "element" turns white. Rich Condition: The rich condition is a state where the mixture is comprises of more or excessive fuel and less air. The occasion when a man would lean on the bosom or breast of another was at the meal table, as John did with our Lord (cf. Lean-burn means pretty much what it says. I think its blue because there is not a lot of oxygen in the pipe. he has a 350 crate engine that was sitting on jackstands for about a year in the garage. A lean-burn engine has an air-to-fuel operating range that is fuel-lean of stoichiometric; therefore, the exhaust from these engines is characterized by medium to high levels of O2. It tells the computer if the fuel mixture is burning rich (less oxygen) or lean (more oxygen). Boiler is a Munchkin wall-mounted. Sensors, their Functions, and Interactions. Why Does My Car Exhaust Smell Like Sulfur? Credit: John Millar/The Image Bank/Getty Images A smell of sulfur coming from a car's exhaust pipe is a good sign that there is a problem with the catalytic converter, according to Cars Direct. What Causes An Engine Run Lean? The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber. at BLUERAY Recall, poorly tuned BlueRay's had a tendency to burn sooty and rich, emitting Carbon, CO and NOx in their exhaust. Just remember, that too lean of an air/fuel mixture can increase engine temperatures and cause engine damage. Fouled plugs, sooty exhaust, if it smells rich then it probably is rich. Flashcards. Please sticky!!! Banshee Jetting FAQ by: BenBB. If it does you know that in the rpm range your having the issue with you need to richen up your mixture. You said rebuilt, is this a rebuilt original carb or a rebuilt remanufactured carb? Also is it a Holley 1920? I once had a remanufcatured Holley 1920 and one of the retainer rings in the power valve came out and the check ball was just rolling around in the float bowl. The fuel pressure will jump up 4-7 psi and the engine will go rich. Re: Flames out of exhaust After a long search for the right carburetor rebuild kit (I have the Kohler CH730), I decided to rebuild the crab. 5 Reasons that Cause Your Car Backfire - Diagnosis and Troubleshooting which has an open exhaust valve, out of turn. All fluid levels has been monitored and they are stable and normal. The only time when combustion temperatures can go down in a relatively rich mixture in a Diesel engine is when the engine is grossly overfuelled, such that. Three things are required for a flame to propogate: 1. Worst-case scenario: Lean conditions can and do destroy engines. Is it the VALVES? Single Cylinder Briggs and Stratton OHV VALVE ADJUSTMENT Procedure and Specs - Duration: 17:13. Dennis Kirk has been the leader in Powersports aftermarket parts and accessories since 1969. oxygen In case of a car to emit flames it must have these three. of detecting the air-fuel mixture in the exhaust from _____(rich) to ____(lean) off and the key out of the. Two Measurements of Combustion Efficiency. I would try and lean it out just a touch at idle and up the jets by 2 points to fatten up the WOT circuit. If you’re still seeing multiple misfire codes, it’s time to examine the timing chain or belt to see if the valve train is out of time with the crankshaft. It seems to happen more as the engine warms up. I just re-read this and it might be confusing so just ask questions away so it is good resource for everyone. Okay if it's just the exhaust manifolds then it's probably running lean. This may or may not be evident with a stock exhaust due to the baffles and converter but with the slip-on it would allow the straight path the ability for the gas causing flames to pass through and out the exhaust where it is burnt on the way out. Bear in mind that the engine will always transition from lean mixture to rich mixture between injection cycles, which will give an "average" of stoichiometric air-fuel mixtures/ratio. I had to tweak the straw on my sprayer to get a richer mixture. Features includes mandrel-bent stainless steel construction, a pair of FlowFX "straight-through" performance mufflers and large 4. when it is very hot and humid it makes the air alot thinner and therfore makes a engine run richer as well. if exhaust can go out, air can go in. It doesn't seem to smell like rotton eggs so I don't think its a head gasket issue. What is O2S11 and O2S21? Rich and Lean Condition Explained. Having a air/fuel mixture rich enough for all racing conditions will allow you to get all the horsepower out of the engine while getting as many laps as possible from a tank of fuel without overheating or doing any engine damage from having too lean of an air/fuel mixture, this is one of the many tricks it takes to beat the competition to the. The exhaust is designed to handle so much spent mixture and don’t forget a portion of the is mix is being recycled and NOT going out the pipe. backfiring - lean or rich? i'll be checking it out this coming weekend. 4 for the engine and 2 in the exhaust and have some gas blowby in the exhaust and have the sparkplug spark the gas blowby. Cal exhaust fabricator and bike restorer. What cannot get out blocks what needs to get in. A lean mixture will burn so slowly that a flame will still be burning in the cylinder on the next intake stroke which will light off the incoming charge. This, of course, is in open loop (WOT) mode. The O2 sensor indicated we were a tad rich on the pilot and needle. I asked a friend about this and he told me to check the exhaust stacks, too rich, black, too lean, white, nice grey color and your right on the money. More discs move the power band up to give you more top-end power, and lean out the carbureted fuel mixture. Odor of unburned fuel - In cases of a very, very rich mixture you may smell some unburned fuel coming out of your exhaust. 4 Do not wear yourself out to get rich; be wise enough to restrain yourself. Beyond two turns out, you need a larger jet for sure. While not often associated with a carburetor problem, an exhaust leak is often overlooked and can lead to off-idle hesitation and deceleration pops. Calculated Load = Current Air Mass X Atmospheric Pressure @ sea level Maximum Air Mass Current Barometric Pressure Figure. The tuner adjusts in a matter of seconds in 6 zones, including an accelerator pump feature for more throttle snap response. Is it the VALVES? Single Cylinder Briggs and Stratton OHV VALVE ADJUSTMENT Procedure and Specs - Duration: 17:13. The EVO R series draws on our rich heritage of making power. A drop of water or spit on the engine heat immediately sizzles. Don't know if one exists, I've just heard about them. Three things are required for a flame to propogate: 1. The flame is relatively cool and it produces a lot of soot. The EGR sits on this portion of the intake manifold; round port is exhaust flowing into valve, rectangular is exhaust out to the engine via the intake manifold ports. The idle mixture is set for starting an engine which is much too rich for taxiing. Having an air/fuel mixture rich enough for all racing conditions will allow you to get all the horsepower out of the engine while getting as many laps as possible from a tank of fuel without. ­Th­e oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. Why do the exhaust flames from cryogenic stage engines appear to be separated from the nozzle? Stack Exchange Network Stack Exchange network consists of 175 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. My relatively new Husqvarna (couple of years old) spits out blue flame from the exhaust too. Barely runs at that. A backfire is simple, either caused by incorrect valve timing, ignition timing or a oddly lean mixture. Recovery Center Wichita Falls Tx (FCR), a leading addiction treatment center in the US, provides supervised medical detox and rehab programs to treat alcoholism, drug addiction and co-occurring mental health disorders such as PTSD, depression and anxiety. You may have some or all of the symptoms depending on how and why you are running rich. Fuel burning in. This melts engine parts. Lean mixtures tend to burn slow and raise the exhaust gas temperatures, overly rich mixtures can burn even slower (to the point of some of the fuel burning in the pipe) and raise the EGT even higher. The faulty sensor can cause a too rich or too lean condition. In the really bad old (carbureted) days, all it took was a spark plug in the tail pipe. When the atoms of a gas or vapor are excited, for instance by heating. Hint: Do the stoichiometric balance with moles of fuel under lean and rich condition separately. 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. The current flow needed to maintain the sampled gasses will either be positive or negative depending on the gasses being rich or lean. My manual was not clear on the number of turns out from lightly seated. If you're running really rich, you can even get flames out your exhaust. Getting inaccurate data will make the. Whatever the problem is, recognizing when your engine is running lean is important for maintaining the health. How did the fuel get into the cylinder in the first place?. If you are new to Bike Talk, be sure to register for free and join the conversation. he has got the high speed jet too lean. A quick inspection can not only tell you if it’s time for new spark plugs, but can speak volumes about your automobile’s engine condition as well. Below, you will find some examples of Mustang computer codes, arranged separately by year range and tips to help you recognize your specific ECU code. However, it is uaually true that if you dump a lot of fuel in it will make a higher flame coming out, unless you also increase the amount of air going into the furnace. Here are some symptoms of an engine that is running too lean: 1. If it is black smoke that would seem to be coming out of the muffler exhaust then you may be that the engine is running to rich like if you left the choke on. And the Installer Series pipe kits allow for the flexibility that is needed to build an exhaust for a modified vehicle. A lean mix ignites earlier, burns way hotter and is still hot leaving the cylinder, and at the manifold you'll see temps as much as 300F hotter than normal. engine light would come on but go back out. has developed an innovative and disruptive technology which achieves such emissions targets but which also has the. When the fuel-oxygen mixture is imbalanced, however, cooler pockets are produced in the flames because the fuel is not consumed properly. I set the air mixture slide value to minimum air but still see mainly orange flame, not much blue. So it keeps burning all the way out the exhaust pipe. i will get off the gas and most of the time it will just stall out. Today was a little cooler outside , so I scooted over to my parents palce and fired it up. Never use an open flame to locate a leak. Am I smelling a lean mixture?. Misfires are one of the catalytic converter's worst enemies. it will cause all kinds of spooge. You mentioned plugs are black (rich) and it bogs (lean?). Then u can fix the air filter cover and lean the mixture. As far as lean goes, higher than normal operating temps, plugs look like they're burnt to a crisp. I've found leaned at about 1500 adequate. Dies while accelerating from idle. There is an oxygen sensor tip located on the inside of your exhaust pipe; the oxygen sensor observes the percentage of oxygen in the exhaust. Testing with a vacuum gauge will confirm a blocked exhaust system. Lean mixtures tend to burn slow and raise the exhaust gas temperatures, overly rich mixtures can burn even slower (to the point of some of the fuel burning in the pipe) and raise the EGT even higher. You can also determine if you need to jet the carb based on how the bike rides. Commercial LPG fuel having an average composition of: 23% propane, 76% butane, and 1% pentane was used. This test result tells you that the O2 sensor is seeing a constant rich air/fuel mixture. The PCM uses this to determine if the mixture is rich, lean, or just right. The poor guy on the other end of the phone is giving me every intimate detail about his modified engine in hopes that I'll be able to rattle out the exact cause of his most recent piston seizure. This is how:. 5 Reasons that Cause Your Car Backfire - Diagnosis and Troubleshooting which has an open exhaust valve, out of turn. If the mixture is too lean, it may burn very slowly and unevenly. It communicates with the ECU via the voltage it produces. The exhaust system manages both pressure and vacuum cycles the engine runs. Typically if everything is right 3 to 3 and 1/2 turns out is correct with Carter and Rochester carburetors. Anytime the air/fuel mixture is off enough in one direction or another combustion becomes erratic. " Poor fuel mileage is also a common complaint when black smoke comes out of the tailpipe. Now obviously it's not a problem of constantly running too rich or too lean. I have a 2000 Maxum 3300SCR with twin Merc 350 MAG MEFI engines (Bravo 3 OD), in which a complete valve job was done on the port engine. Have an 05 Mustang GT. I'v heard that flames and pops coming of half throttle is a Lean and rich condition? Heard that running with the lid off is easier to tune?. Explore millions of exclusive, royalty-free, stock photos, images, and videos. Small engines use a series of small explosions in the combustion chamber to generate power. What would cause the mass air flow sensor constantly put out low input are rich or lean if they need adjustments. That should do it! I know it seems silly to go back and forth between lean/rich but you want the adjustment to be right in the "Sweet Spot" of the mixture range and the only way to tell is by going lean/rich a couple times. A rich condition is no good because it will leave some gas unburned, increasing pollutants out of the tailpipes and of course, waste fuel. Exhaust gas analyzers have been in the shop since the 1940s. The ECM uses that information to adjust the fuel ratio to keep the engine. If there is too much fuel and not enough air, the engine is said to be “running rich”, or “has a rich mixture”. GOOD NEWS!!! It is running good now FYI it does NOT have a ACR. A car exhaust smell can be due to many different things. Blue flames out the pipe is generally unburn't fuel (to rich). Whatever the problem is, recognizing when your engine is running lean is important for maintaining the health. Bulgur-Stuffed Summer Vegetables. It was time to revisit things and make some corrections. i will get off the gas and most of the time it will just stall out. Dropping the primaries will give you that lean pop then it will take off when cruising, but fine from a dead stop. It gets worse when the weather gets colder, it pops louder and more often. Some engine builders look at the top of the exhaust ports to check their fuel setting, with a light brown indicating a good air/fuel mixture. In less than 2000 miles one of the pipes had absolutely none left inside. Read honest and unbiased product reviews from our users. of detecting the air-fuel mixture in the exhaust from _____(rich) to ____(lean) off and the key out of the. The exhaust from this cylinder passes the oxygen sensor and then the report to the ECU is that this whole bank is running lean (too much oxygen, due to the one cylinder running lean). well, the oil in the fuel ends up as a mist in the crank case. We take great pride in our customer service and continue to innovate the industry. exhaust system emission control. Since most ported MAFs typically lean the system out 10 to 15%, the SVO pieces actually bring you back over into a too rich condition (or as I like to say, enough to purposefully overdo it). Deep Fryer Exhaust Smoke I have an old second-hand Cecilware countertop fryer. 7) Carter Only. So, there are two potentially problematic cases here: There is too little oxygen (the mixture is too rich) There is too much oxygen (the mixture is too lean). Dies while just idling. the initial setting is 1 1/2 turns counterclockwise from fully but lightly all the way in. While medication and other treatments are important, many experts say that adopting an anti-inflammatory. There is no rattle sound on the cat. I finally tried using steel wool and some polish as well as wet sanding and managed to clean them up pretty good for what they looked like before. Lean-burn engines are designed to operate with a weaker mixture, exhaust to feed information back to the fuel-injection system. Alert oncoming traffic if possible. Read this page to help you get your scooter to to performnace. The car exhaust port is important as it neutralizes many of the harmful fumes that come out of the engine. Three things are required for a flame to propogate: 1. Everything you ever wanted to know about Banshee jetting! While the specifics listed are based on the Banshee's stock carbs, the principals remain the same and are similar for other carbs (and anything else with a carb). A lean condition occurs when a car burns more air than gas. The character of each condition is subtly different though. Today was a little cooler outside , so I scooted over to my parents palce and fired it up. Eventually, enough is there and it ignites due to the hot exhaust. TEST 1: Inducing a Rich Condition. O2 Sensor Slow Response - Rich to Lean. I've already checked and ruled out vacuum and/or exhaust leaks which would introduce fresh air into the system. Carburetor Troubleshooting Guide. My wide band A/F meter says that I am between 12-14, (mostly on the high side) not considered rich for what I understand, but the tail pipe is completely black! or does the black carbon indicate incomplete combustion, even if the meter is measuring the correct air/fuel ratio?. Take the plugs out and if they look clean you're good to go. The poor guy on the other end of the phone is giving me every intimate detail about his modified engine in hopes that I'll be able to rattle out the exact cause of his most recent piston seizure. With the testing of all three cats out of the way, it was time to unplug the exhaust and let her rip without that pesky brick in the exhaust. strokes—because the exhaust valve is closed and so no exhaust gas is fl owing out of the exhaust port and past the probe. cthowards did a good job of describing the process. What Causes Backfire? When the engine on your motorcycle has an emission system malfunction, such as an exhaust leak or a moment of running rich or running lean, backfire can occur. Choose from an expansive collection of maps dyno tuned in-house by Vance & Hines. Little oxygen = rich so it leans the mixture out. Shutter fully open, fully closed, it still smokes. To appear lean, you'd have to have a dead cylinder fuel-wise (no fuel at all). Rich gas and lean gas are the two types of natural gas that are distributed in Belgium via different networks. that usually happens afterhigh rpm for a while. At idle, or under partial load, they're running lean. The only concern I have is that when I am using my air shifter which is 99% of the time that it back fires and shoots about a foot long blue flame from my exhaust. Why does my engine spit or backfire? First off, you need to determine whether it is backfiring out the exhaust or back up through the carb. The piston make two complete passes in the cylinder to complete one operating cycle. also mine does not seem to hold an idle very well. " Any calibration other than ideal …rich or lean will reduce the efficiency and power!. So it keeps burning all the way out the exhaust pipe. ¶ To maximize ICE efficiency it is necessary to operate lean (air dilution) with overall dilution levels beyond the limits of traditional homogeneous flame propagation combustion modes 13 Combustion Technology Key Challenges Lean SI - Gasoline Ignition and flame propagation limits along with emission challenges Lean SI Stratified Charge -. The main purpose of the O2 sensor is to keep the oxygen level in the exhaust constantly changing. The first thing we'll do, is to see how fast the oxygen sensor responds to a Rich Condition (that you will induce yourself). Lean it out again to the point of misfire and then richen it to where it is smooth again and go 1/4 to 1/2 turn rich. Always make sure your carburetor isn't set too lean as it can cause similar symptoms. Combustion Temp's for an IC Engine they could lean it out to approximately 12. Intermediate jet too small. Blue flames are shooting about six inches out of the front opening.