Edelbrock Carb Backfire When Cold

A leaking, burned, cracked, or stuck valve could be the cause. 52 roller tip rockers and a Competion Cams 268 camshaft. Set aside the float bowl and let the epoxy dry. Either way a leaky fuel bowl on your carburetor, probably isn't going to end well. The carburetor regulates the flow of fuel and air to an engine. Single fire ignitions can often eliminate carburetor backfiring since they do not produce a wasted spark in the rear cylinder. When the fuel pump is turned on or when the engine is first started, watch closely for signs of flooding. So long crank times are not a characteristic of the Edelbrock performer carb series. so i rebuilt the carb, which is an edelbrock 1406 with electric choke. Each Edelbrock Performer Series carburetor is flow tested in the factory for both air and liquid flow so flooding is rare. Double checked the timing, it was a little advanced, about 16 deg with no vac. Amazingly an early Ford carb is as simple to rebuild, and adjust as is an air-cooled pre-1971 Volkswagen carb. The carburetor is unaffected by engine backfires, which means that there are no power valves to blow out, and the rods can be changed in seconds without carburetor removal or fuel draining. by jrinaman on Sat Jun 02, 2012 5:14 pm 38 degrees would be with vacume connected. My car runs fine, don't have any driveability issues. As far as the backfire - this might be either from the carb issue or it could be related to that rattle you mentioned - you could have a loose connection at or near the head - this can **** air and cause a backfire. setup is the best choice for off-road performance enthusiasts. Now I know why Edelbrock says his carbs are ready to go straight out of the box Not enough adjustments and backfire if you do try to make adjustments. I even bought a new coil because it doesn't hurt to have a spare. it had trouble starting and had a bad hesitation on acceleration. Mine does the same thing (Edelbrock carb & intake). Don’t be mistaken…. Either way a leaky fuel bowl on your carburetor, probably isn't going to end well. Mini Clubman 1275 GT, 1979. On to the problem. New gaskets, o-rings, and fuel inlet needles and seats are often required to return a poorly performing motor to good working order. This is the Edelbrock performer carb that comes in a two-piece aluminum body construct that allows the metal to expand and constrict without buckling and maintains a cooler internal temperature. 493 lift) Also only pulls 10 inches of vacuum at idle, stock heads with 10. i stll have a backfire-stall on a quick take off with a cold motor. It restricts airflow through the carburetor. Actually, I'm not sure if it's a traditional backfire. At the split of the "Y" or "T" there is a vacuum operated valve that diverts the air intake to come from the rapidly heating exhaust manifold area rather than the cold, wet air from the front of the car. we have glass beaded intake to clean it up and check it over. More backfiring, not as bad, but still not acceptable. You need to hook the dist to ported vacuum, also time it with the dist vacuum hose unhooked and port on carb blocked temporarily. Let me mention how I have sorted out the headaches in my own fashion. Next thing I know the bike is running badly. Buy online, pick up in-store in 30 minutes. If they are clogged the fuel mixture will be too lean for cold operation on that carb. Replacing the fuel pressure regulator fixed it. ive read a lot of forums and a few lead to bad distributor, i am using a used. STUMBLES WHEN COLD. Other things to check are, is the fuel boiling in the carb or is the gas line near hot exhaust etc?Or to look at it as a possible rich condition,is the choke. A friend's old-school mechanic said that if you are using an Edelbrock carb (mines a 1406) with electric choke (normal choke is ok), there is a manufacture defect/issue where there is a vacuum leak. For a year I ran this engine with a quadrajet carb. Best Y block carb choices. When in motion, it will backfire out the carb. Lately it starts great, idles fine, full speed under no load is also good but once I put a meaningful load on it the engine dies out, stutters and/or bogs down. the issue i am having is i have a 1968 charger with a 383 engine stroked to 500 cu in. It's like the ignition is almost being draw down or grounded when there is a large load applied. Sometimes when I get in my truck it starts fine and then as soon as I step on the gas it misses and backfires. Restart and pump gas pedal to keep it running and it will spit fuel out the top of the carb and sometimes spits fire. Does that mean the carb is too rich for my 305? Thanks, Greg M. The original Edelbrock carburetor design is still available and offers affordable performance for hundreds of applications. Didn't fiddle with any adjustments besides float because it ran fine before. If it backfires through the carb, check the compression on each cylinder for a stuck valve. One time, it blew the plastic piece connecting the vacum hose to the power brake booster. I put a 1406 Edelbrock carb and 289 intake on the bronco over the winter. Get product details, choose a store, and get directions. Installing the Edelbrock Qwiksilver Pumper Series carb on the XR650R. 00 Optimized for maximum power at elevated rpm (from 7,000 to 10,000 rpm), the Victor X manifold is designed for. Edelbrock had the marine grade carburetor #1409, but it was priced nearly $200 more than the #1405. The one barrel carb on the 6 cylinder engine on my Edsel keeps backfiring unless I pull out the manual choke a little. Stock Pre 96 Carb. I would double check that you don't have a vacuum leak somewhere either although I think that would pop out the carb. Each Edelbrock Performer Series carburetor is flow tested in the factory for both air and liquid flow so flooding is rare. Then I replaced the carb with another quadrajet made my JET performance with an electric choke. Looking for edelbrock carb guru I have an issue with an edelbrock 650 carb. Save on Carburetor Choke Parts with great deals at Advance Auto Parts. Edelbrock packs 70 years of proven performance experience into every product it makes. If it SPITS through the carb its a sign of a lean condition, cleaning the carb out and installing one size larger pilot jet will help ( pilot jet #46 for a 88'' and a 48 for a 95'') I say to clean it out because its been sitting so long. Protect your eyes from spray back, then spray carb cleaner into the pilot jet. If good driveability and fine tuning are your concerns then bring home the Edelbrock 1405 carb. Now back to the list…. You need to hook the dist to ported vacuum, also time it with the dist vacuum hose unhooked and port on carb blocked temporarily. The carburetor is unaffected by engine backfires, which means that there are no power valves to blow out, and the rods can be changed in seconds without carburetor removal or fuel draining. Deceleration back-fire, rough idle, and throttle lag can be quickly adjusted by tuning your carburetor. I have tried tuning the carb myself but it's my first time trying that. The Edelbrock E Street EFI system features a universal throttle body designed to fit any V8 engine originally equipped with a carburetor and intake manifold with a square-bore, 4150-style carburetor flange. At a stop or long coast, it will resume the malfunction. A single barrel carburetor will normally squirt a single stream; while a two or four barrel carburetor will normally squirt 2 streams. dude trust me its not your valves, some people just want to jump to the most extreem thing first, most of my new young mecanics would act like that yrs ago when I was a shop forman, a little knowledge is a dangerious thing, as a good mecanic should do is allways start with the easy fix first then move on to the next harder, your running lean and in o5 or 06 they started to plug the idle. 010" wire will pass through the pilot jet. Seems like we have disagreement on what it means to backfire when letting off the throttle. While it is doing this, it seems that the engine loses power. edelbrock 1405 / 304 backfire -hesitation- stall (long) i stll have a backfire-stall on a quick take off with a cold motor. I hope this helped! Posted on Jun 10, 2010. This Edelbrock Victor Jr. The left side is stamped with a four-digit number. along with the hiccups i get. 04 silverado backfire and missing 3 Answers. If no changes have been made to the bike, and it previously ran well, a lean mixture can be traced to a leaking inlet manifold or leaking exhaust (often at the interface of. A lean condition severe enough to cause a backfire usually shows up at cruising speeds as a surge and a flat spot under light acceleration. it sat for about 2 years without being driven so there were some problems i had to address immediately. Buy online, pick up in-store in 30 minutes. Holley remains the carburetor of choice but there are nice alternatives from Demon, Edelbrock, Summit Racing, Quick Fuel, and Proform. The one barrel carb on the 6 cylinder engine on my Edsel keeps backfiring unless I pull out the manual choke a little. hey were easy to adjust. we have glass beaded intake to clean it up and check it over. Flooding can be caused by dirt, small particles of hose cuttings, floats and inlet needles which have settled during shipping, or by other conditions as discussed below. 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. I'd screw them in and out until you find the fastest idle and try that out. Got a 1997 yukon that starts good cold but backfires through the carb when warm ? Discussion in 'General Discussion' started by nokuy97, Mar 10, 2010. i asked a qeustion about my Stang a little while ago, it was continuisly backfiring and i couldn't get it right, everything seemed to be right, timing, advanced timing. How to Cure Carburetor Stumble May 13, 2014 Dan Sanchez Fuel Delivery , How-To and Tech Tips , News , Tech , Tech Tips 2 Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. Whether you need to replace an aging inchstocker inch or are looking for a performance carb to top your inchhot rod inch, the Edelbrock Performer Series carbs are the best choice for performance and value. Please Select A Vehicle To See Parts For Your Car. 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. There is a high idle screw for when the choke is working on cold start and what you have to do is get someone to step on the gas pedal while you watch the linkage from the front and once the linkage is fully open you will see a screw head facing forward on the bottom of the linkage. It features annular-flow primary boosters with calibration for improved off-idle and cruising, which also delivers improved fuel atomization, eliminating flat spots during idle. and such(it all started when i putted on a set of world windsor jr heads. i bought the 750 avenger$220 then a holley modification book for $12,i. Fully-synthetic oil improves efficiency of the engine by decreasing carbon accumulation and also has outstanding, capability to prevent cold-starts. But, it would not rev cleanly, and was backfiring through the exhaust. How to Adjust Electric Choke on an Edelbrock Carb. Edelbrock's AVS2 Carburetor: Improving Response and Modulation By Tommy Parry June 17, 2018 Finding a good compromise between having the response and throttle modulation of EFI with the price and versatility of a proper carburetor is challenging. Edelbrock offers a large assortment of carburetor accessories for your Performer Series, Thunder Series AVS®, AVS2, Quadrajet and NON-Edelbrock Carburetors. Ask and ye shall receive. Got the carb back today and installed with no changes. Please advise me on what the real symptoms of lean vs rich system is. Recent service includes a new Edelbrock carburetor, fuel pump, and tune-up. I checked and adjusted the carb with a vacuum gage and I’m getting a reading around 46-48 on both sides. If it backfires through the carburetor, back the idle mixture screw out another 1/4 turn. More backfiring, not as bad, but still not acceptable. Seems to run great out of water with hose attached to it, but not in lake. This was causing the spark in the dizzy cap to jump to one of the other cylinders corresponding brass terminals. 2) Slow flooding. It is probably from a combination of choke setting, accelerator pump shot, and idle mix settings. It seems to be the 'standard' replacement for a Carter AFB or AVS. Now, on with the back story. Single fire ignitions can often eliminate carburetor backfiring since they do not produce a wasted spark in the rear cylinder. i bought the 750 avenger$220 then a holley modification book for $12,i. If the choke comes open too quickly, the engine will be lean when cold and backfire. "Backfire" can mean a couple of thingsyou can get a pretty loud bang out the carb if you're leanshortened my eyebrows once looking down a Holley while flipping the throttle. I purchased a Husqvarna 128LD from Lowes several years ago. You should observe a healthy squirt of fuel from the pump jet. However, the steps may be dependent upon each other, so you will probably have to go back and forth some after an inital read. The points look new. A friend's old-school mechanic said that if you are using an Edelbrock carb (mines a 1406) with electric choke (normal choke is ok), there is a manufacture defect/issue where there is a vacuum leak. It was during this ride at one of my stops that it started having trouble starting and the carb backfire started the air filter on fire. The first one had a manual choke on it. Eventually engine will backfire out the exhaust. Turning them out creates a richer mixture and screwing them in makes the idle air-fuel ratio. so I have replaced the carb, new fuel and filter, new spark plug, new air filter. Install the new carburetor studs/bolts (if necessary) and place a new carburetor gasket on the intake manifold. Re: Small popping/backfire after new Edelbrock carb install. Not to disagree with you, but the Victor series (according to Edelbrock's site) starts making power at 3500 RPM. Replace the float. i have a question about a 1813 thunder series avs carb i purchased in 2007. Carb Rebuilding SU & Zenith Stromberg Carb Rebuilding & Restoration. The 440-6 Bbl. It’s a 4 barrel carb that can easily fit on a 350 Chevy. Thanks for the info. Some carb kits contain floats and some don't. Ran the same. The Edelbrock E-Force Supercharger system part 1537 is a STAGE 3 Pro-Tuner System that delivers upwards of 651rwhp and 626rwtq for your 2005-10 6. An accurate and easy way to measure this is by placing a 7/16" drill. 2100 Identification. The main jet is the supplier of fuel to your engine at the top end of the RPM range. How to Adjust Electric Choke on an Edelbrock Carb Adjust the choke according to the way the car runs when it is cold. It runs really rough and starts backfiring as it warms up. It's got no power. Stuff a rag under the joint between the flexible fuel line and the carburetor fuel inlet line to catch any leaking fuel, and detach the hose from the inlet line. With a cold start, the engine will start rather quickly and then sputter out. 113" SecondaryJet-. I have an edelbrock performer intake and 600 cfm performer carb. It surges high and low and backfires through the muffler, cold or hot. 030), Comp Cams small "Thumpr" (. A backfire through the carb is an indication of an exhaust valve open when ignition occurs. I know, 'cos I have the same problem. Possibly damaged by a backfire condition. This number is the model number, which can be looked up to discover the type of carburetor on hand. The big four suppliers of 4 barrel carburetors today are Edelbrock, Holley, Quick Fuel and Barry Grant, each of these carburetor designs have strong and weak spots. Backfiring between shifts, and discovered, by trial and error, that enriching the mixture solved the problem. Also check the intake for leaks with wd40 or carb cleaner while its running. I sit at 4700 ft. Edelbrock's dyno proven combinations make it simple to change the appearance and performance of your induction system in a single box. Once I've been driving it for 10 minutes or so it's fine, or close to fine. Edelbrock Carburetor, Performer Series, 4-Barrel, 600 CFM Manual Choke, Satin Finish Carburetor, Edelbrock Performer Series, 4-Barrel, 600 CFM Manual Choke, Satin Finish Designed and calibrated for optimum street performance. The coil had gone bad. Here's the scoop. Turning them out creates a richer mixture and screwing them in makes the idle air-fuel ratio. I have a 84 mercruiser 470. Carb Synching When Do I Need To Synch My Carbs This is a procedure that needs to be done at least once a year during maintenance, any time you remove and replace the carbs, or a least any time your bike feels like it running rough. Browse your favorite brands affordable prices free shipping on many items. ITS A GOOD CARB. so i rebuilt the carb, which is an edelbrock 1406 with electric choke. Backfiring and paffffff sounds (to me at least) sound like timing problems. I'll keep the Holley. finally deduced the fuel pump was bad, no fuel to carb. Its backfiring out of the carb and keeps dieing. A worn camshaft lobe or bad timing chain could also be at fault. The carburetor that we would recommend is based on how the customer will drive their car and the engine package that is in the car. After-burn is similar to back-fire, which is the burning of fuel in the intake port of the carburetor. We usually refer to an exhaust backfire as a "backfire", and backfiring through the carb as "spitting" or "coughing". This after-fire is a by-product of backfiring through the exhaust, something that was a common sight in older car models. I bought an Edelbrock 500cfm performer carb on the weekend. Although the car is old, the engine is a brand new Jasper 350 with an Edelbrock 600 cfm carb and a new Mallory ignition. When the engine is warm, less fuel is required. Includes both timed and full vacuum ports for ignition advance. Q: The carburetor is backfiring and won't hold a cold start fast idle. It restricts airflow through the carburetor. We have all the parts you need, and we make finding the right parts. Not a backfire anywhere AND. once its warm no problems. At the split of the "Y" or "T" there is a vacuum operated valve that diverts the air intake to come from the rapidly heating exhaust manifold area rather than the cold, wet air from the front of the car. The units are both hard starting cold and will backfire through the carb. I just recently rebuilt my 350 sbc engine, the engine will start fine and idle fine, but when i seem to quickly give it full throttle it will backfire through the carb, the carb is an edelbrock performer 600cfm electric choke, has performer plus cam, rebuilt machined 882 heads, new carb, distributor cap and rotor. 1) Replace the power valve. Clean the float valve good and set the float level. The guy said use your finger plug the hole indicated by the picture below. Edelbrock had the marine grade carburetor #1409, but it was priced nearly $200 more than the #1405. Protect your eyes from spray back, then spray carb cleaner into the pilot jet. 107; Metering Rod-0. could also be loading up, jetted a little high. It's not as consistent as I thought, sometimes it will backfire a few times and then run smooth for a few seconds. In hot weather - frustratingly bad. The curb idle screw is on the driver side of the carb sticking forward toward the front of the engine. Anything new since 2006 - or does all the above about cover it? (Little confused by the comment "I took the choke off", not that I would do that. Cold Engine Driveability Condition. That can cause it to backfire. Carburetor Choose for Me to Minimize Cost Choose for Me to Minimize Cost Related Parts Accelerator Pump Diaphragm Carburetor Adjusting Tool Carburetor Air Flow Meter / Synchronizer Carburetor Fuel Inlet Fitting Carburetor Repair Kit Carburetor Return Spring Fuel System Repair Manual Throttle Linkage Throttle Linkage & Ball Joint Throttle. Now, on with the back story. Check the choke operation. If all you did was switch pipes should be able to just richen it a little without changing jet sizes. Problem: My Motor Hesitates, Backfires, And Won't Hold A Steady Idle. Then I replaced the carb with another quadrajet made my JET performance with an electric choke. Dismount the low idle solenoid from the carburetor by removing two philips screws holding it to the carb top. It is a popping resonating sound generated by a lean condition on deceleration. It features annular-flow primary boosters with calibration for improved off-idle and cruising, which also delivers improved fuel atomization, eliminating flat spots during idle. Edelbrock Electric Choke Conversion for the AFB Four-Barrel: by Jim Clark, Hot Rod M. Didn't run well cold at all. On the first test ride and to get it inspected it was a little hard to start when cold. I totally rebuilt the carb, changed timing, changed rods and jets, you name it. That kind of popping/backfiring. Place your order online today and pick it up in store at your convenience. While it is doing this, it seems that the engine loses power. I notice the hoses that go to the flame arrestor have a small ( pea sized) accumulation of milky oil, likely from mixing with this water somewhere. Includes installation instructions. Seems a little strange that the problem only occurs when the engine is warm. Manifold is an Edelbrock Performer RPM. Changing the exhaust or the intake from stock means readjusting your carbs as youve altered the back pressure from the exhaust and the flow of air from the airbox. Some carb kits contain floats and some don't. The original Edelbrock carburetor design is still available and offers affordable performance for hundreds of applications. What causes Backfire with an Edelbrock 4 barrel carb? I would think the engine is out of time or the spark plug wires are not installed correctly. I always called that symptoms of a vapor lock. Edelbrock had the marine grade carburetor #1409, but it was priced nearly $200 more than the #1405. Whether you need to replace an aging inchstocker inch or are looking for a performance carb to top your inchhot rod inch, the Edelbrock Performer Series carbs are the best choice for performance and value. Each side of the opening feeds four cylinders on a V8 engine. The Edelbrock AVS2 Carburetor. A lean condition severe enough to cause a backfire usually shows up at cruising speeds as a surge and a flat spot under light acceleration. The richness is necessary because cold fuel in a cold engine does not vaporize as readily …so the effective richness of a given mixture is reduced. It may well be a little lean, I'm not familiar with the Edelbrock. How to Adjust Electric Choke on an Edelbrock Carb Adjust the choke according to the way the car runs when it is cold. There is an offset passage in the carb body. Shop for Edelbrock Performer Series 800 cfm Square Bore 4BBL Carburetor Part #: 9962 for your vehicle. It’s a very slight problem, considering the potential for troubles … —the engine has a non-standard aluminum cylinder head, a mild ‘hot rod’ camshaft, and the carburetor, intake and exhaust systems are all upgraded, non-standard items. I have an Edelbrock Carb - auto choke. So, the popping you are hearing is not back-firing. Understanding the Backfiring Mechanism. You did not send a model number, so I don't know if the information I am sending you will be helpful. Possibly damaged by a backfire condition. I bought an Edelbrock 500cfm performer carb on the weekend. It's not as consistent as I thought, sometimes it will backfire a few times and then run smooth for a few seconds. Thanks for the reply. with it on ported vacuum when you give it gas it will advance by mechanical and vacuum advance. Lawn mower owners should contact the machine supplier or manufacturer on enhancing the air flow to the engine to prevent backfires. The points look new. Purchase Edelbrock Fuel Line and save!. A lean condition severe enough to cause a backfire usually shows up at cruising speeds as a surge and a flat spot under light acceleration. The Carter-designed AFB and AVS carburetors sold by Edelbrock, and the non-boost-referenced Holley-style carburetors can work well on a low-boost-pressure/mild blown engine. 52 roller tip rockers and a Competion Cams 268 camshaft. It seems that it is somewhat down on power in the cold weather. 1999 Husky WR 125. I'll keep the Holley. Edelbrock had the marine grade carburetor #1409, but it was priced nearly $200 more than the #1405. The tractor backfiring has several causes. Get product details, choose a store, and get directions. Older vehicles with carburetors require maintenance and cleaning to keep fuel and air flowing correctly. Look at the color of the spark plugs, they should be tan in color. I even bought a new coil because it doesn't hurt to have a spare. the car is running a Carter RAKX-O carburetor it runs great round town or under verying load, but under a constant up hill load I can field the power drop off and she starts to spit and backfire through carb. It only took me a day to make my 1405 edelbrock *(Adapt-O-Brock) linkage to work on my 79 C10's "new"305 I installed--the same problem as yours,after getting a V8 accelerator cable (mine was a six cylinder)and installing it--I couldnt get it to return to idle--I had to remove the bracket that holds the cable and file the holes out making them more like slots,and pused it closer to the carb. Adjusting the accelerator pump to the top hole will increase the pump stroke and provide a bit more fuel on acceleration. A lean condition severe enough to cause a backfire usually shows up at cruising speeds as a surge and a flat spot under light acceleration. When cold, the fuel coming out of the jets doesn't vaporize as well, which leads to an improper combination. Real backfiring is actually the bike "spitting up" in a sense, backwards through the carburetor or intake. for now i want it to run stong without spending alot of money. If it isn't, the pump solenoid will stay closed all the time and waste fuel. it had been setting for several years due to a coil problem, i repaired the problem a few weeks ago, the kill wire had grounded out killing the fire, so i put it on a toggle switch, the mower will crank and run, no problem, but it popps or backfires thru the carb, you can see fire in the carb, i. Engine 351c Backfiring/ And Not Running At Idle. Real backfiring is actually the bike "spitting up" in a sense, backwards through the carburetor or intake. Edelbrock had the marine grade carburetor #1409, but it was priced nearly $200 more than the #1405. I get VERY slow acceleration and a few backfires under load. Carb backfiring on hard acceleration! Jump to Latest Follow 1 - 20 of 32 Posts Then you say it backfires when cold only, well i would say its the accelerator pump. Application. so I have replaced the carb, new fuel and filter, new spark plug, new air filter. 5 hp OHV engine, engine model=28N707. It was during this ride at one of my stops that it started having trouble starting and the carb backfire started the air filter on fire. Although the car is old, the engine is a brand new Jasper 350 with an Edelbrock 600 cfm carb and a new Mallory ignition. It sounds like a possible lean condition which is usually worse when the engine is cold,unless your running a choke and it runs good until the choke kicks off. Sounds Lean to me. Edelbrock offers a large assortment of carburetor accessories for your Performer Series, Thunder Series AVS®, AVS2, Quadrajet and NON-Edelbrock Carburetors. At the split of the "Y" or "T" there is a vacuum operated valve that diverts the air intake to come from the rapidly heating exhaust manifold area rather than the cold, wet air from the front of the car. The backfire is through the exhaust not the carb and happen when the throttle is opened up from idle (roughy 800 rpms) This started to happen after I changed the plugs, plug wires and removed the header to get the plugs. Put on fuel injection, ran slightly better when cold (-12*F to 35*F) but still not acceptable. I have an edelbrock performer intake and 600 cfm performer carb. In my how-to video I will walk you through the basic principles and fundamentals of what you are adjusting and how it will impact your bike's response. STUMBLES WHEN COLD. Remove the stock throttle assembly and cables (note where they are routed,. For engines to run efficiently, the spark plugs have to ignite the air and fuel at the right time. It does it as soon as you turn the A/C on. The cold starts are seriously bad. Whether you need to replace an aging inchstocker inch or are looking for a performance carb to top your inchhot rod inch, the Edelbrock Performer Series carbs are the best choice for performance and value. so after doing some. In a cold engine the fuel condenses out of the fuel / air mixture onto the passageways of the intake manifold and walls of the combustion chamber. Bike won't start - just backfires occasionally. Fresh rebuild on a 360 with a refurbished Edelbrock 1407 750cfm carb from national carburetors. I'd screw them in and out until you find the fastest idle and try that out. It's like the ignition is almost being draw down or grounded when there is a large load applied. The edelbrock marine 600 cfm is around 100 dollars less money, and everyone I have talked to that has ever replaced a holley with an edelbrock has said how much easier the edelbrock is to get set up, and keep running right. Restart and pump gas pedal to keep it running and it will spit fuel out the top of the carb and sometimes spits fire. If it is moved left, it receives less fuel. It's not a loud bang,just sounds like starter fluid being ignited backwards thru the carb, then the starter spins. Backfire flame arrestors are designed to prevent the ignition of gasoline vapors in case the engine backfires. Now I have read that the secondaries only open up when under a load with edelbrock carbs. Correcting Problems, continued. The spacer will prevent hot start issues due to the cast iron manifold heating the carb enough to boil our ethanol-laden gas out of the float bowl, and provides a very crisp throttle response. For connecting a throttle cable, I recommend cable ball joints from pegasusautoracing. First be sure that the carburetor is fully warmed up and the choke is off because some choke mechanisms limit the throttle opening when cold. It's backfiring a little, only on acceleration. Backfire is caused by combustion in the intake manifold. The transition from idle to part-throttle is essentially the hand-off of the Idle System to the Primary Main System. The carb is an Edelbrock 1406 (electric choke) 600 cfm unit. Float Circuit. I automatically blamed t on ethanol. ive read a lot of forums and a few lead to bad distributor, i am using a used. The carburetor regulates the flow of fuel and air to an engine. How do you convert EFI to Carb on a 1987 Chevy truck 350? That 87 truck already has a carburetor on it. I hope this helped! Posted on Jun 10, 2010.