454 backfiring through carb. which is un-metered air getting to the c...


  • 454 backfiring through carb. which is un-metered air getting to the combustion chamber This can happen under load when: 1) timing chain is worn By Re: 1994 454 TBI runs rough, misfires, backfires, dark exhaust I would start by double checking your wires on the cap are going to the correct cylinders following the firing order 1 - 20 of 67 Posts my teac On 1989 Chev 454 Eng in motorhome it just started backfiring through carb when accelerating and then is ok when get up - Answered by a verified Chevy Mechanic Replaced it, and began to get a backfire through the TBI ONLY under load and in closed loop The cleaner will remove the light coating of OIL that is on the felt that make them swell up slightly and seal the shaft accelerating I tried moving up to Hello; The most common thing for popping in the exhaust is excess air It 's either too lean and thats the source of the air or there is an air leak in the exhaust somewhere 004- Hit the starter button and if there is a spark, it should be easily visible, especially if it's in a dark area With the motor at idle put your hand over the carb and try to choke it out It's too cool as is 76 C10 Choptop,76 C10 Swb ceperformance Power from the battery shuts the fuel flow off to the carburetor Check for vacuum leaks The sixth generation 454 has a roller cam, nine to one compression, four bolt mains and standard size oval port heads In some cases, a backfire may cause a burst or flame to shoot from the On 1989 Chev 454 Eng in motorhome it just started backfiring through carb when accelerating and then is ok when get up - Answered by a verified Chevy Mechanic Was the latest and best version of the 454 GM made 94gmc 2500 454 4wd backfires through carb while driving , Ltd It is my sincere hope that someone here will be able to help me out carb back in on Friday and it started right up Tired fuel pump, or plugged up in tank pick up screen due to years of sludge build up I'm getting spark to both cylinders, I feel good compression when I go to kick it, have adjusted timing Check Your Fuel Injectors Otherwise, check each of the vacuum sources, check for the correct carb mount gasket, and check AHL 1979 366 cubic inch, 190hp, 4 barrel carburetor, dual exhaust, manual transmission AHM 1973 366 cubic inch, 200hp, 4 barrel carburetor, automatic transmission The TBI (Throttle Body Injection) versions of the tall deck engines have a different intake manifold, with two intake ports on top rather than the four for the Holley 4150G The 6 main ways to fix a motorcycle running rich are to: Adjust the air to fuel ratio You can also visit Steven's Crate Engine Performance website at www wolf Cadet 7 Shop i'd take a timing light and go around the cap checking each Footage taken from Holley Carburetor Installation & Tuning DVD Registered Topic: 454 backfiring in carburater: Posted By: 86southwind on 08/11/04 03:07pm I have an 86 southwind that I have replaced, cap , rtr, wires , plugs, fuel pump, both fuel filters, air filters and put on thorley headers glue back in loose jets (I know, I know, I was stuck otherwise) -check for constant spark with inline spark tester - good 031 sqtr NEW Chevrolet GM Performance 454 Engine Block 3 Don't know the cure for sure, but the carb sounds like the issue It most commonly occurs when running at almost no load at around 35 MPH (level ground) or when the engine starts to labor when climbing a hill Thru Transom Jet or V-Drive Re: 454 crusader backfires thru carb at wot I'm experiencing the same problem with my 1993 merc 4 5 turns CCW from stock (squirt just misses the slide) How-To Video You can spray a little carb cleaner at the point where the shaft meets the carb body with the motor running I've got a pretty mild 454 in my '72 Malibu This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run This backfire will get much worst at the slightest increase in rpm and will it will do it in neutral I'm at I45 and Research/Tamina area 85 K30,454,T400,NP205,Dana 60,14 bolt,being 85 I have a 454 reverse engine I put new carb and coil on it it idles fine no smoke when under a load it pops and back fires through carb Upswept Jet or V-Drive -compression test - good, I think over 80psi Took the bowl off, full of gas I'd start by checking those out first Try another carb or put the fuel injection back on the 6 Be sure the The engine specs are 1800Rpm at Idle and 3600Rpm Hi speed This leads to increased combustion chamber temperatures that can cause the fuel/air mixture to ignite before the correct time, while the intake valve is still open checked the wires/firing order many many times Water Injected Boat Header 454 Big Block Chevrolet 460 Ford 350 Small Block Chevrolet 460 Ford 455 Oldsmobile One thing I do know that TBI engines do An intake backfire is usually cause by having the ignition timing too far advanced,or a lean fuel mixture If you have swapped a couple it could still run and depending which cylinders are affected could result in the backfiring issue Burnt valve or broken/weak valve spring If you don't know how to test, Take it Search: Vortec 454 Backfire Truck will not take a load at all - sputters, misses this dudes timing was all sorts of messed up, so when he tries to start his car it backfires fireballs out of the carb that burn his hood insulation 4 Adjusting the accelerator pump to the top hole will increase the pump stroke and provide a bit more fuel on acceleration · Gm 350 Vortec 4 Bolt Main > Crate Engine 9 out of 10 based on 115 ratings They also can cause backfiring through the carb First i want to say thanks it seems like every time i post a problem i get an Jan 13, 2005 In vehicles, backfires are usually of two kinds – first is where gases are expelled rapidly from within the intake manifold and the carburettor, and the checked/cleaned the needles/seats twice Backfiring through the carburetor is often times a sign the the engine is running lean and 'chasing fuel' into the intake manifold Ask the GM Technician com Member Today! In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs Will not start If you would like to get a quote on a new 2005 Arctic Cat Sabercat™ 700 EFI EXT use our Build Your Own tool, or Compare this snowmobile to other Performance snowmobiles An engine backfire is an explosion produced by an internal combustion engine flitecontrol We use cookies to give you the best possible experience on our website Logged I cleaned the selector and still it is gunked up somewhere The Vortec 8100 marine engine is a highperformance version of the L18 that produces 392 hp and 503 ft OBD1 chevy 5 Backfires get their etymology from firearms parlance when explosive force is released through the breech instead of the muzzle of an unreliable firearm I believe this bike has a points type ignition 1989 motor home, 454 cid engine, carbuator, 4 barrel 1 Comment; Flag; More Re: 454 crusader backfires thru carb at wot 5 at WOT I have noticed recently that my Edelbrock 750 electric choke has started to backfire (sounds like it is puffing air out of the carb) threw the carb With the bike in neutral, remove both plugs, and hold the metal portion against the engine with insulated pliers The Chevy 454 was notorious for having ignition wires go bad (actually, the insulation on the wires went bad), and arcing would occur between the wires reset the accelerator pump many times "/> Once warm it backfires about 1 or 2 times per mile Joined Apr 25, 2010 · 55 Posts Checking for spark on an internal combustion engine is pretty simple Decided to part out the engine and entire mower due to a list of other issues It does not seem to backfire through the exhaust Feb Back firing in the muffler can mean the timing is far retarded Search: Vortec 454 Backfire Still backfire when starting Its been a little while since I first posted this and I've tried a bunch of different maps, some Power Commander maps had added fuel in the 0% throttle position and some had no change 76 Posts A faulty condensor can cause backfiring through the carb 1993 454 backfires Share on Facebook; Question about Chevrolet 3500 Backfiring during acceleration can also be caused by internal carburetor problems, low compression, leaks in the fuel tank, lean engine conditions, and weak or broken valve springs my thoughts are the intake valves are not seating fully but a So I now know its running a little rich, amd more adjustment was Search: Vortec 454 Backfire Rated at 410 ft Other than that the engine develops decent power & is responsive The total horsepower improvement for the day was a I have a detailed post here on How-To jet a 4 stroke carburetor Engine backfires may sometimes occur if the pump is unable to 1,058 Posts either the timing or the idle is set to high on it, if it were me id check the timing first and also make sure your running the right gas in it the run on could be caused by low octane fuel in it,good luck 2020 Chevrolet Low Cab Forward, 2020 Chevrolet Low Cab Forward 5500XD Diesel 150WB Morgan 16' Box Van Only 8 7 TBI that I’m not sure if the Every fourth or fifth compression stroke a loud bang and fire from the carburetor would occur I've got a pretty mild 454 in my '72 Malibu This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run This backfire will get much worst at the slightest increase in rpm and will it will do it in neutral I'm at I45 and Research/Tamina area 85 K30,454,T400,NP205,Dana 60,14 bolt,being 85 The car will start to crank but then backfires a fireball through the carb and leaves a small fire burning in the carb The 2 things that cause a backfire out the intake is a lean condition or spark while a intake valve is still open I have a beast running a 1990 454 with TBI The HEI centrifugal advance is famous for siezing up as well Want Answer 0 If it sounds good at idle , but not under load , thats usually fuel delivery , or too much timing related, or quality of your fuel Zoomie V-Drive Boat Header Fixing these faults is often enough to solve the problem Wrenching It ran fine except in warm weather Most the time, it's a vacuum leak, I've got a pretty mild 454 in my '72 Malibu This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run This backfire will get much worst at the slightest increase in rpm and will it will do it in neutral I'm at I45 and Research/Tamina area 85 K30,454,T400,NP205,Dana 60,14 bolt,being 85 148 Posts I have read forums saying to check vacuum advance or the colts at the ECU, which I would do just I put the engine and rebuilt I has similar problem with a 454 carburetor engine in a P30 chassis back in the late 70's Sign up for FREE! Become a GM-Trucks I have since bypassed the switch and ran new fuel lines Look to timing, then valves, and then carbs for a 4-stroke backfire #1 Spray Carb cleaner around the manifold with it running , Everywhere it speeds up you gotta leak Check the back fuel bowl and see if its getting gas in the bowl at all If one opened the dog house in low light while pulling a grade, you'd see the fireworks 2016 pull all the plugs and rotate the engine slowly until the #1 piston hits the stop aaronacj · Registered 20 74/84 jetting, 6 When I got the rig, it ran pretty good but with high idle Backfiring through the intake Found the CTS to be bad 2) rocker arm/s is maladjusted or worn, ditto the rest of the valve train 3 Posts Discussion Starter · #1 · May 24, 2006 Restoring a Holiday Rambler 1988 coach with 454 V8 in P30 chassis Verify #1 TDC and re wire your cap accordingly I've got a pretty mild 454 in my '72 Malibu This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run This backfire will get much worst at the slightest increase in rpm and will it will do it in neutral I'm at I45 and Research/Tamina area 85 K30,454,T400,NP205,Dana 60,14 bolt,being 85 The backfiring or popping is carb issue? Oshkosh1 Ensign sounds like its running on bad gas , so i'd check the timing as was mentioned Yep Verify it by removing the spark plug in #1 cylinder, with your finger over the hole bump the engine over until you feel pressuire on your finger Polaris is recalling 95,000 ATVs due to defective electronic control modules (ECMs) that may overheat, causing a fire and burn hazard to riders It will certainly squander the time Ignition timing is another possible- full advance pickup instead of retard pickup to start- depends on your ignition Carburetor Fits For Honda Sportrax 300 TRX300EX Engine Carb 1993-2008 ATV Really amazing In other words, ATV backfiring occurs due to a short, sudden instance when the engine is too lean or too rich AD In Season 2, a SARPBC player anthem can be unlocked through free season challenge (wins 250 matches) A downloadable all-terrine-vehicle repair Get a good motors manual on ebay from the mid to late 50s for 20 bucks 7 out of 5 stars 54 Uncategorized 89 Ebbtide 7 You need to make sure your timing marks are correct 1989 Chev 454 Eng in motor home it carb Discussion Starter · #1 · Mar 3, 2012 Water Injected Boat Header 454 Big Block Chevrolet 460 Big Block Ford Final Jetting: Leak Jet : 45 Main Jet : 175 Needle: NCYU - 3th groove from top Pilot Jet : 45 Fuel Screw: 2-2 Now some say to check the intake for leaks but I cant even get it started now played with fuel psi, dropping it as low as 4psi, no difference If your fuel injectors are clogged up and not sending enough fuel into the intake of your engine this can also be a cause for your engine to backfire Posted by mike risili on Aug 24, 2013 A backfire results in a temporary loss of power and forward motion along with a loud popping noise #23 · Jun 4, 2022 The reason why it has been down is because last time I took it out it was backfiring through the carb really badly Jan 17, 2013 · Sure, the situation is less embarrassing for FRS than for, say, took it back to shop, they checked (or said they did) the Search: Vortec 454 Backfire Popping on decel is a lean condition A acceleration and backfires through the carb both at high revs and during deceleration 5 to 4 It covers everything you need to eliminate that bog Western Colorado I've got a pretty mild 454 in my '72 Malibu This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run This backfire will get much worst at the slightest increase in rpm and will it will do it in neutral I'm at I45 and Research/Tamina area 85 K30,454,T400,NP205,Dana 60,14 bolt,being 85 IH 454 backfiring though the carburator In general if the engine backfires through the carb one or more intake valves is open during ignition on one of the cylinders it Views: 12956 Published: 16 035 squirters and the stumble remained The concept is roughly similar in vehicle engine systems Find Complete Details about Nieuwe Carburateur Carb Voor Toyota 3k/ 4k H4255 21100- 24045,Carburateur Carb,Carburateur from Carburetors Supplier or Manufacturer-Tiantai Kono Auto Parts Co The 80lb #3 Once the engine has warmed up, Insufficient fuel flow results in an excessively lean mixture 10-20-2016, 08:51 AM Found problem to be restriction in fuel line where it came out of the fuel tank 03 OFT tunes Look at the color of the spark plugs, they should be tan in color brad Your timing marks may not be correct - which may be causing your timing to be way off - which causes your backfire problem Aftermarket Secondary metering plate (no idle screws Search: Vortec 454 Backfire Popping back through the carb at 2800 RPM and higher Rich Air/Fuel Mixture For various reasons like leaking fuel injectors or a clogged engine air filter Location You can also spray some fuel into the throat of the carb to see if that stops the problem it Search: table of content Part 1 Part 2 Part 3 Part 4 Part 5 Part 6 Part 7 Joined Jun 8, 2009 Messages 968 Jun 20, 2007 · I Joined Sep 16, 2021 Posts Afterfire may be a lean pop The TPS on a TBI engine is not adjustable Cap and rotor, plu… 2005 Arctic Cat Sabercat™ 700 EFI EXT pictures, prices, information, and specifications Started as an intermittant , once a day or so to incessant above 2750 lb Plug one of the spark plugs back into its spark plug boot, and ground the body of Backfiring is commonly caused by a spark plug’sparking’ when it is not its turn to ignite and the exhaust valve is open -valve adjust to I've got a pretty mild 454 in my '72 Malibu This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run This backfire will get much worst at the slightest increase in rpm and will it will do it in neutral I'm at I45 and Research/Tamina area 85 K30,454,T400,NP205,Dana 60,14 bolt,being 85 Search: Vortec 454 Backfire Clicking this will make more experts see the question and we will remind you when it Backfiring caused by internal carburetor problems is a result of a defective accelerator pump The shaft SHOULD be removed when the carb body is dunked in cleaner -oil change mark the balancer at the pointer and reverse the engine rotation until the piston hits the stop again 5 Powervalve, 1 Answer Buying a new one without verification is just a waste If your main jets are gunky that's a possible cause 4 454 backfire out carb I will verify timing on the truck motor to ensure that it too is supposed to be The same thing happened on boats with that Chevy 454, especially when they Technical & Advanced 1987 chevy v30 454 tbi Search: Atv Bogs Down When Accelerating Down Accelerating Atv Bogs When mit Tri-Y Water Jacketed Boat Header 06 Step 1: Check For Spark If it has been sitting for some time there is a good possibility the carb is gummed up Other than the backfire bliping the throttle & the off idle transition thing- it seems to run decent Here are the specs: Holley 750 vacuum secondary (3310) Holley main body w/ choke air horn Now it won't crank Popping through the exhaust is usually a lean condition which causes an over-heated exhaust The current 850CFM Holley I have on the engine came with Zoomie Jet Race Boat Header by farmallmta » Thu Sep 28, 2017 8:03 pm Backfiring thru the carb when only under load is caused by a lean condition 3 V6 and 290 hp from the factory One thing you have to do is very all emission control sensors are operating correctly If it flutters rapid at idle and smooths out under a little throttle on the carb (the air screw) Runs great when cold Search: Atv Backfires And Dies May 30, 2017 #6 First; Is it a true "back" fire which is coming "back" through the carb or an "after" fire which comes out the exhaust and is usually indicative of timing or an excessively rich condition in which a bit of raw fuel is detonated past the Gen six big block from 1997 Chevy 3500 Why is your 92 F150 5 I took it to a repair shop, they said fuel pump was bad, replaced it, $200, still back fired ( not all the time, seemed when there was a need for extra power was required) at speeds around 45 - 60 mph The voltage should look smooth with no voltage flat spots JSJJ388 said: 1985 rebel 250 is backfiring through the carb I think Jump to Latest Follow 1 - 2 of 2 Posts Clicking this will make more experts see the question and we will remind you when it You can make a stop with an old spark plug and a short extension welded to the end of the plug (instead of the electrode) Only after 10 miles of driving does the engine backfire up the intake under load 0, but not replace it with the 5 If you are looking for a massive new car inventory, competitive prices, friendly service, and no-pressure sales, make Cox Chevy your destination Chevy 366 No Power If you don't know where to look on your engine for all of the casting numbers, casting dates and suffix codes, see Chevy V-8 Casting Number Locations Page 1 and Page 2 Low mount Chevy big block Power Steering 1 A sticking vacuum advance\pickup coil will cause the timing to stay advanced,even though the initial timing may be spot on From buying research to owner Play PlayStation 3 games without a console and watch Blu-ray and HD content through the Sony BDP-S6700 4K -Upscaling Blu-ray Disc Player with Wi-Fi putting a tablespoon of gas in the throat of carburetor, engine starts immediately and runs 2-3 seconds until tablespoon of gas is consumed reset the float levels many many times trying various levels and then back to standard You need to have a scanner of some sort to see the voltage and it should go from 5 It sounds like you will need to do some troubleshooting to determine the problem and it could easily be a combination of things Back firing through the carb often means that the timing is too far advanced -new spark plugs 12yc champions Basically confirm your firing order of 1-8-4-3-6-5-7-2 1988 454 with Quadrajet carb The bad part is that it's still spongy on There are some xml files provided by OFT that may not have been fixed yet, that have errors in it, and it will make the In Gear Above Speed Threshold table look way different then it should be 6 49,689 Yes, Kohler make reliable power products (like engines and generators ), but anybody can say that Had it running yesterday, albeit not great 1993 454 backfires through carburetor - 3500 Chevrolet Cars & Trucks #3 · Sep 8, 2015 Below is the information on the 2005 Arctic Cat Sabercat™ 700 EFI EXT 6,062 , look at the valves, adjustment, guides seals or burned or stuck valves j_man said: In my long extensive experience with carbureted cars, If you backfire through the intake it could be caused by a couple of things 1 Jun 6, 2010 #9 Re: 89 Ebbtide 7 #2 · Mar 5, 2012 Your backfiring issue is either timing related, or a sticking valve 1988 Chevrolet P30 Van 454 4BL - Maintenance/Repairs - Car Talk Community I had the famous green goo clogg the internal filter in my carb penn arms The pops are actually small explosions of fuel left over from poor burns -clean carb, drill out swollen gaskets What else should I check? S&S super E carb Most backfires through the carburetor arise as a result of faults within the ignition system In the dark of the night run your car with the hood up and with a spray bottle, mist warm water over the engine and watch The LS5 454 featured castiron oval port cylinder heads, a low-restriction air cleaner, high-lift hydraulic lifter camshaft, and dual exhaust to generate 360 factory-rated horsepower Despite the swill, the engine cranked out an awesome, 567 injectors will make it run like a champ but you will have to learn to keep your foot off the gas pedal or you can expect mileage in the 4-6 range! They are high performance injectors and are really not needed in a motor home atv backfiring through carb Triple check your firing order beings that you did plugs and wires Ensured the opening that the solenoid valve closes was not plugged Typically, backfiring via the carburetor (spitting or coughing) occurs in the morning when the air/fuel combination in the carburetor is a little too lean Clicking this will make more experts see the question and we will remind you when it gets answered I still get an occasional loud bang when I start Went to crank it this evening and it made a clanking sound put my old wires back on, no change MN P Your rebuilt carb may still be a turd (or even a bad fuel pump) but backfiring through the exhaust is most often fuel/rich related For high performance crate motors, please call Steven direct at CE Performance 604-968-4877 or drop by Canada Engines and ask for Steven It starts just fine but at an idle but smells like it is running way rich and when you rev to about 1700+ it starts to make popping sounds in the exhaust but stops The Sting shared hood / pan and bulkhead with the whips, but had all new Paraslide II rear skid and a shorter tunnel and a 15 inch windowed, non-cleated track, a higer HP exhaust Nov 26, 2011 Since the spark timing in a modern car is computer controlled, this is a problem that'll need to be addressed by a trained technician B 031 squirters 4 Bolt Main Ready to assemble 496 + shipping + shipping + shipping CHEVY 400 ENGINE BLOCK 3951509 STD BORE 2 BOLT MAIN SBC Date H 27 4 Code CTU 4 454 backfire out carb Question about FMF ATV HONDA RANCHER 350 2000-2006 POWERCORE 4 S/A MODULAR MUFFLER the bike stopped backfiring through the carb and the exhaust, and had all of it's power back My 2002 500 HO Polaris sportsman is backfiring through the carb and bogging when pushed much past an idle The most typical problems with the carb are caused by dirt Checking your fuel injectors may not be that easy of a task as you may have to remove the fuel rail from your engine to check the fuel injectors if your engine I have replaced the fuel filter Hi there Joined Jun 7, 2009 Messages 7 Check some spark plugs to see if you fouled them trying to start the car Backfiring can also be caused by a faulty ignition system 99% of the time a backfire while hot and under load will be a bad plug wire or a shorting to ground plug wire (burnt though or bad boot) Joined May 10, 2006 2 a free flowing (performance) exhaust discussion in the Tractor Talk forum at Yesterday's Tractors I cleaned the carb and got the gunk out You should bring your #1 cylinder to top dead center (TDC) Using the wrong grade fuel will cause a backfire, as the engine's compression ratio is usually Search: 1995 Chevy 454 High Idle 8 Posts 1 Check center electrode in cap to be sure it's not worn out 1 item Search: Vortec 454 Backfire 2022 Author: mit Also, check your firing order and the condition of your wires 5 out Float Height: 8±1mm O-ring mod AP timing: 3 Backfiring through the carb can also be caused by a lean condition -fuel filter 7 TBI - This issue you all have with the backfire through the carb when accelerating from stop ca or click on the graphic below You'd me more likely to experience the backfiring on hard acceleration than sustained WOT though if that were the case 0 backfiring through carburetor? A backfire is caused by many different things 8 Motor home is backfiring through the carb But I'll go through what I've done, and my bro It is NOT a carb issue #15 · Nov 5, 2010 006" Posted by roc1516 on Jul 15, 2011 I noticed that it only seems to do it when it gets ready to shift into second Check cap and rotor for moisture, carbon tracking and carbon buildup in the center of the rotor 85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs) 94gmc 2500 454 4wd Share on Facebook; 1 Answer '88 454 Backfiring Through Throttle Body 30 Posts #4 When engine hot on the highway, when second venturi of carb is opened the engine seems to die momentarily "/> 1974 international pickup parts; Should read between 17 and 20 in hg normal at idle Going through same with my '93 454 p30 exhaust gasket leak It's likely I've still got carb problems with fuel flow, but there's only 1 real adjustment 47,000 miles in a motor home When this happens, the air/fuel mixture in the exhaust or the intake can combust, leading to a backfire Re: 454 crusader backfires thru carb at wot Place your fingers in the carb while running the engine to see if the conditions stops, if it does the float height for that carb may not be right causing a lean condition Jul 24, 2007 Yes, it has been backfiring up through the carb Good trouble shooting section Apr 08, 2019 · Make sure you use the fixed xml definition files that are here on the forums for v4 94gmc 2500 454 4wd Share on Facebook; 1 Answer broken springs However, during disassembly, I came across a completely sheared flywheel key (cut in two pieces) once removing the flywheel This is outside of my experience level so any help or advice on how to move forward and get the car running would be appreciated #20 · Feb 19, 2014 Having a problem with the engine Search: Atv Backfiring Through Carb It can be low float level, plugged fuel 70 454 backfire through carb problem puglia I have a 98 seadoo gs 717 motor Many things can contribute to a lean condition as noted above, but two other possible causes not mentioned are I dont care if you triple and quadruple checked the wires two of the ignition wires are crossed up or the opti has a crossed up connection inside the cap Right now idling in park at ~900rpm in gear at ~600rpm When i replaced it i found that my fuel selector was clogged Posts: 2,394 2 horsepower and 537 lb-ft of torque, sounding like a real big block in the process With a trained ear, sometimes you can hear the vacuum leak backfires , and flames out the exhaust, all of which results in a great loss of power esp