Edelbrock Carb Stumbles Off Idle

Keep it level -- fuel remains inside and can leak out. The AFB (Aluminum Four Barrel) carburetor was produced by Carter for original equipment cars from 1957-1971. Q-Jet stumble from idle - appreciate any help The carb had a stumble before but now it seems a little more. Find Edelbrock Performer Series Carburetor Calibration Kits 1480 and get Free Shipping on Orders Over $99 at Summit Racing! Edelbrock knows carbs. I tried to tune out that off idle stumble when I had time for several months thinking that Chevy had a reason for using the standard screw. 15% OFF +$7. it has a 600 cfm edelbrock carb but when i adjust the idle screw down the engine shuts off. A carburetor that is too small will restrict airflow limiting engine power and speed at higher rpm's. Edelbrock 1406 carb. I have had many problems sense I went to a pumper Carburetor on my XR650R. Response is instant and seamless. After many thousands of miles of faithful service, I noticed a slight hesitation in accelerating from cruise and made a mental note that a carburetor overhaul was due. The choke butterfly should be fully open, as the engine is warm. Otherwise, it seems to run fine. and may run a little rich. How to Tune Edelbrock Carburetor Carb Idle Mixture Screws Choke Metering Rods Jets Fuel Air Vacuum Carburetor adjustment errors can affect the entire engine. The carb comes with everything shown here for the XR650R. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. Carburetor will come with a new mounting gasket and instructions on how to make the final adjustments. 340 everything stock , car idles great, cruises at 50 60 70 miles an hour great , but hesitation off an idle streets lights, stop signs ect, have 4106 edelbrock electric choke new base gasket , no leaks that i can find , what hole should the accelerator pump be in , and never taken carb apart , anybody have any suggestions , this is very annoying, thanks. My '96 KTM came with an Edelbrock, nasty nasty carb and I had to get rid of it. and i can hit the throttle at any other speed and its fine. signal as you come off idle and that would cause a lean condition. So I had a bog then backfire from a stop with meadium to heavy throttle. I have a 1963 Riviera and have had nothing but problems with the carb. Carter AFB Carburetor AFB Carburetor Identification Look for 4 numbers followed by a S. (stock engine shouldn't need nozzle changes but not impossible). hi nice tech tip ,. I wanted to make sure. fast idling when you start a carbed engine is normal. Have used every combination of springs and metering rods plus all pumpdrive link positions. edelbrock super victor intake and. 7) Check idle solenoid, especially for power/ground, replace solenoid if necessary. Or, does it stall/stumble (torpor) when you open the throttle fairly quickly? If it's the former, there may be a problem in the carb's idle to off-idle transition circuits. An idle system will have an idle jet/restriction that must be changed to supply the desired fuel mixture for idle and off idle engine demands. The car has a very mild 351C 2V with and Edlebrock Performer, and a 700 Holley double pumper carb. I have installed the Pro Flo 3 on my '66 Chevelle. Let me start off by saying this is not a Holley Vs Edelbrock thread. The engine vacumn holds this piston down with the metering rod at the bottom" the thickest part" " the leanest setting". Reconnect the accelerator arm to the throttle arm and off you go!!! This is how to set up for MAX squrit, so if less is what your motor needs than turn the adjusting nut more in, not out. Also, you may want to record your calibration settings in the table below and keep it with your vehicle records. hooked up, I could see the idle was too rich. Went up to Pink (2spring sizes larger) and I got my foot in the peddle acceleration. Atomization Abounds. so i checked for leaks. Points because we have it, we are out of time, and because points have never failed me, ever. On top of that we adjust the idle so it is not too high or too low and we even set the fast idle. I'll cross my fingers and try that out this weekend. The most common problem I see with the engine is it's inability to idle. Over 150,000 miles of trouble free injection and no hesitation at all. Many QJs need work to get them right also. 95 shipping. Cruise hesitation will be tuned by changing the step up springs on the metering rods. We installed an Edelbrock air/fuel ratio meter last weekend. might try that if you havent. First, the 1406 is lean, on purpose, on the primary side. I do have the wrong intake for the street but no matter what i did to this carb it would still bog from the start. Seat of the pants opinion, no off idle hesitation like the stock carb and better midrange. I am putting a 800 cfm Edelbrock carb on my 462 that is around 500+ hp. I have driven around the block mostly and have probably about 30 miles on the car. A tuning book comes with the tuning kit. As you can see, there’s much more to setting idle mixture properly than. New fuel pump, timing chain, cap,rotor,wires,plugs vacuum advance and mechanical advance ( Mr gasket 929G with lightest springs) Timing is set - initial 17 and total 36. There are several things that are intriguing about Edelbrock’s Pro-Flo 4 EFI. Transition slot exposure is critical because it affects both idle quality, idle air / fuel mixture as well as 'tip-in' or 'off-idle' response. Edelbrock 1406 Help Needed *FIXED* A little background: Stumbles off idle , starts fine cold, vacuum leaks checked, replaced my recurved dizzy with brand new stock one this morning. 447 lift), 1. 10 gears, Stock motor with CompCams 268 cam, headers, Edelbrock intake and a new Holley 650. The idle screws should be set between 1/2 to 1 1/2 turns to start with and adjusted after warmup by turning them in until the engine starts to stumble, them turn them out, counting the turns until it stumbles again, then turn them back 1/2 way. Please advise me on what the real symptoms of lean vs rich system is. The rockers have been re-adjusted and the carb. Factory 1406 comes with YELLOW springs. We put a holey carb on but the air cleaner and shaker would not fit right and he bolted the shaker to the hood. Holley 4160 Carb Hesitation. If your idle mixture is off and you start doing other things, it will lower vacuum, which can change metering and it also means that your idle speed screw/ primary throttle. the discussion was my issue with Holley. We had a slight hesitation w/o opening the back barrels before, the bigger nozzle on the accell pump seemed to cure that. ) - 4802 Idle Pickup Tubes-(We highly recommend that you pull the original Idle Pickup Tubes during your rebuild to ensure carburetor passages are completely clean and idle pickup tube orifices are not. To narrow it down, tap the roll pin out of the accelerator pump lever by using a small pin punch or a small finish nail. Edelbrock 1406 Help Needed *FIXED* A little background: Stumbles off idle , starts fine cold, vacuum leaks checked, replaced my recurved dizzy with brand new stock one this morning. This is done one at a time. I might try dialing back the timing a degree or two, keeping it on ported see how it is.   If you are using a. The bikes front tire climbs up all the time. First, I would definitely buy a timing light and know your timing. Both of them had a bad stumble off idle that I could never correct. The 600 cfm is absolutely fine for the 305. In your case , since this is an intermittent problem - yours has dirt in the circuit. hooked up, I could see the idle was too rich. If you have any questions, give a call to our toll-free Factory Tech Line. With a specific calibration for improved off-idle and cruising performance, this carburetor eliminates the hesitation – and subsequent frustration – associated with a mismatched or poorly tuned carburetor. Would a vacuum leak affect idle as well or just the scenarios I've listed? I haven't yet checked the total advance, which I plan to do tonight to see if the vacuum and mechanical advance is operating correctly. You'll gain some low end power and better idle quality with a dual plane over the Torker single plane manifold. Start by measuring the idle vacuum and if it is below 18 inches, torque the manifold bolts and see if the problem goes away. If you're having problems with your idle the first thing to look for is air leaks. I ran the system in stock form through the '97 season. Ewhitaker0020 Erratic Carb at idle. cant get to idle correctly. This carburetor is a direct replacement for 289 and 302 Engines. As mentioned, each carburetor is different, but this circuit typically involves a mechanical lever that compresses an accelerator pump diaphragm through a discharge nozzle. My last effort was to clean and reset the float levels. It seems like when the carb goes from the idle system to the priamary main system it goes lean for a split second ( it shows on the LM2) and I get a hesitation or stumble or it is the rod pulling out of the jet, not sure, Edelbrock tech guys tell me that I am out of the idle system before 2000 rpm???. Can't seem to get the Edelbrock 1411 to not off-idle stumble, for anything. adjusted as best as I can. once its warm no problems. Simply identify the part number of the product you have purchased or plan to purchase and enter it in the search field below. Problem has been from day one: Hesitation off idle, pop through carb, surges up and down until rolling. Pretty inconsistant, it is a edelbrock avs thunder series 650cfm carb. Clevelands love timing I also frequent 351Cleveland. I have run this carb at high altitudes and fairly steep climbs off-road and it didn't miss a beat. Engine is fairly fresh, about 5000 miles since rebuild. Jesse b suggested it was a fuel delivery or vacuum issue. I am putting a 800 cfm Edelbrock carb on my 462 that is around 500+ hp. i think there is also a screw somewhere that adjusts how high it idles when you have the choke on but i think you usually have to take the carb off to get at it. if you stumble, you've got a vaccuum leak. I have changer accelerator pump squirters and have changed the cam out. The carb could be gummed up (use about half a can on that thing, I do my carbs about once every two months. adjusted as best as I can. If you set this screw all the way in there is a risk of uncovering the off-idle ports so avoid the extremes of the adjustment range. Keep it level -- fuel remains inside and can leak out. new thumpr cam - wont idle below 1k Engine already has an edelbrock 4b carb and performer intake. You either have a rich or lean off idle condition. At the heart of the idle circuit are the idle mixture screw and throttle stop (idle speed control) adjustments. Carburetor problems generally fall into three areas: too lean a mixture, too rich a mixture, or an incorrect adjustment. it stumbles then picks up the load. thats why i purchased this model carb and size. Here's how to tune your Edelbrock carburetor. The intake and carb I have are edelbrock RPM, and 750 cfm carb. Technical and mechanical Q&A about Studebaker cars and trucks. Hesitation at acceleration as well. With a specific calibration for improved off-idle and cruising performance, this carburetor eliminates the hesitation – and subsequent frustration – associated with a mismatched or poorly tuned carburetor. In this range, watch and listen for the following: Off idle to mid-range mixture adjustments are made by raising or lowering the needle height in the slide. The intermediate circuit is the most common circuit that needs tuned. picks up instantly without hesitation, no flat spots, revs like a motorbike easily up to 7k rpm. Summit racing sent us four of the most popular off-road carburetors including a Holley 750-cfm, a brand-new model Holley Street Avenger 670-cfm, an Edelbrock Performer 750-cfm, and an Edelbrock Q. I have it myself and so far I have a larger accelerator pump, a set of pump cams, and I still need to buy larger jets to experiment with, but I have bigger problems to tackle. hi i have a chevy 350 in my 72 chevelle engine has been overhauled but the idle is too high like around 2000 to 3000. i adjusted the idle mixture screws and it didnt help. I switched from a 600 Holley to a 750 edelbrock carb on an old 390. Increasing the idle jets in the metering block solves this issue. You should always regear when changing tire size and especially anything over 35s running 3. Carburetor Throttle Stud Edelbrock 8016. I wanted to make sure. I dont what to highjack this thread, But I am getting a minor off-idle stumble on my Eddy 1407, 750 CFM. The AFB was then available as a high performance 9000 series carburetor up until the late 1990's. I bought the car last year, and it has always had a problem when taking off from a stop. I have an edelbrock 1406 series electric choke, 600 cfm carb on my sbc350 and I have always had hesitation issues with it if you accelerate hard. This is done one at a time. I'm running the MPFI with a FAST dual sync dist. That tells me I'm running lean when the carb is transitioning from idle to the cruise circuit. Simple test is to screw in the idle mixture screws all the way and if the engine does not die, the power valve is bad. You should experiment with that first. I had chalked this up to the engine combination UNTIL I installed an older, used 600cfm edelbrock performer carb on the car to see if that affected the slight hesitiation from cruise. The car would stumble as soon as the throttle was cracked open from idle. I'll cross my fingers and try that out this weekend. edelbrock or other. To find out if this is your issue just remove the idle jets and see if the off idle stumble becomes a flat out bog down. The air valves already opened fully also. With the engine at operating temperature and idling, pull the vacuum advance hose off of the carburetor and "feel" for vacuum by putting your finger on the vacuum port (See Fig. Beyond the idle and accelerator pump settings, the Edelbrock carb has primary (part throttle) and secondary (WOT - Wide Open Throttle) main fuel metering systems. Brochure #63-0443. In spite of all the tricks, parts changes and adjustments it was just the nature of the beast…. 02 aluminum heads and the Pro-Flo EFI. '83 Chevy C-10 Pickup 2WD. Simply identify the part number of the product you have purchased or plan to purchase and enter it in the search field below. Also as for the intake the edelbrock performer is a good intake. A carburetor that is too small will restrict airflow limiting engine power and speed at higher rpm's. Oh the car I'm talking about is a '69 Dart 273 auto. Can't seem to get the Edelbrock 1411 to not off-idle stumble, for anything. any suggestions?. Otherwise, it seems to run fine. If vacuum port at rear of carb is not used, plug with a 1/4" pipe plug. Stiffer springs pull the metering rods up out of the jets quicker when vacuum drops (when you step on the throttle). I have played with this quite a bit and maybe I am expecting too much from this carburetor. The 500 & 600-cfm carbs can be modified to avoid an off-idle lean condition, so they can work well on a low boost pressure single or dual carburetor set-up, but we avoid the 750 and 800 cfm AFB s on street driven blown engines because of a lean at part throttle problem that is inherent with this type of carburetor. I borrowed a friend's 600 cfm Edelbrock carb and it had a noticeable flat spot or hesitation right off of idle compared to the 500 cfm Carter that I use to run on the same engine. To me it was not a 300 dollar upgrade. com (or Ford 4L or Ford 4. The carb comes with everything shown here for the XR650R. 0 Vortec that I repowered (21 ft Sea Ray 200 Sport, previous owner cracked original 4. Holleys are all the same, best performance carb available. I stll have an off-idle stumble, but it's driveable, it doesn't try to stall, just stumbles. I bought the car last year, and it has always had a problem when taking off from a stop. I'm now running pink springs and adjusted the electric choke. My motor has a bad stumble when i eccelerate hard from a idle. YELLOW is too light. I do have the wrong intake for the street but no matter what i did to this carb it would still bog from the start. We installed an Edelbrock air/fuel ratio meter last weekend. Yes, this will affect fuel economy slightly, but probably not much, and I would rather have a slight loss in fuel economy rather than put up with an off idle acceleration stumble. as soon as it is almost back to idle it. If you still run rich try the following. i'm guessing you may be rich given the size of the carb. We bought a reman Quadrajet Carburetor online with an electronic choke. Can't seem to get the Edelbrock 1411 to not off-idle stumble, for anything. It replaced the older AFB carburetor. Example 3445S. kinda like it was breaking up off idle when driving. 5 Pounds Vacuum Test and get 17 to 19 inches All that said, I still have erratic idle (fluctuates +/- 300 RPM) and a bog or stumble mid-range. combustion chamber, eliminated the rich idle condition and removed the stumble off idle. (Read NTX5467's explanation of idle control). running on a 327 (. The guy said use your finger plug the hole indicated by the picture below. as that is what most of the mule motors are if you are sticking an out of the box carb on a 400 to 454 or larger motor. Next I pulled the sec. I also run 16-18 degrees no issues at all except the stumble from off idle which I now believe is the Edelbrock. I switched from a 600 Holley to a 750 edelbrock carb on an old 390. Acts like it is running rich at idle. The flow from the squirters seem fine but I am not a carb guy. Ensure that the carburetor throttle lever came back against the idle rpm screw. Drain the gas then unhook the cables from the stock carburetor. edelbrock or other. The flow from the squirters seem fine but I am not a carb guy. Well we have been messing with the 1406 Edelbrock Carb and ignition timing for several weeks now. Pertronix ign. Hesitation and slight popping during acceleration? Why? What kind of voltage are you reading off of your throttle position sensor? When the engine is at idle. 098 jet and a 075 x 047 metering rod. The air fuel meter showed this flat spot just off idle as a lean condition, obvious because of the flat spot. Re: Need help with carb adj on Edelbrock-350 With the engine OFF , look down the throat while giving it full throttle with your hand. Page 39 1403-1413 Perf Series Carburetor Owner's Manual. (During carburetor overhaul the idle mixture screws should be adjusted approximately 2 and 1/2 turns out from their seat- this should allow the engine to run). 104 in secondary cause there is little lean spot at 5000rpm but its just starting to warm up here as it was snowing last week, so might leave it for a bit to see if air temp will help out. Went up to Pink (2spring sizes larger) and I got my foot in the peddle acceleration. If it was running well and stopped then rebuilding the carb and tuning the accelerator shot would make a lot of sense. Welcome to the world of the Speed Demon 650! I have the same carb you have on the same basic engine setup (302, edelbrock performer rpm heads, cam, intake) I have spent almost 3 years and $700 to try to tune the carb. net and a lot of the post talk is about timing these guys know there stuff about Cleveland from stock to race. If you have an automatic transmission you will need a vacuum sec. In the case of my Edelbrock, the engine will not keep running if either of the two idle screws is turned all of the way in - this is. It has very little or no effect on off idle and larger throttle openings. 600 cfm edelebrock carb (#1406) edelbrock performer cam edelbrock performer intake Mopar performance ignition hooker headers Jegs dual exhuast with magnaflow mufflers A904 tranny with b&m shift kit Lokar kickdown linkage It runs OK, but I have a problem with the off-idle throttle response. Hope this helped!. On that note, I did run a Holley 600 carb before the Edelbrock 1406, and there was only a manifold vacuum source available. I might go up to. Carter AFB Carburetor AFB Carburetor Identification Look for 4 numbers followed by a S. If it doesn't want to idle down then you got a vaccum leak or something. I was curious why there was no stumble off idle, but there is at highway speeds. is recognized as one of the nation's premier designers, manufacturers and distributors of performance replacement parts for the automotive aftermarket. How to Tune Edelbrock Carburetor Carb Idle Mixture Screws Choke Metering Rods Jets Fuel Air Holley Carb Stumble Fix. its only off idle if i hit the throttle hard. I switched from a 600 Holley to a 750 edelbrock carb on an old 390. couldnt find anything. Yes, this will affect fuel economy slightly, but probably not much, and I would rather have a slight loss in fuel economy rather than put up with an off idle acceleration stumble. After seating, the idle mixture screws should initially be adjusted by backing them out two or three turns from their seated position. Atomization Abounds. Many QJs need work to get them right also. -Connect tachometer to determine idle rpm (SEE DRAWING No. The off idle stumble and hesitation on acceleration are classic signs of an intake manifold leak, which is a common problem on 2Fs. The AFB was then available as a high performance 9000 series carburetor up until the late 1990's. 0 V6 OHV equipped Ranger for 10 years now and am very surprised at how little info there is on the net for this engine/vehicle combination. I did notice that when the carb was connected to manifold vac ther isn't a bog off idle, but it doesn't seem to hit as hard if i go WOT from 30mph or so. In spite of all the tricks, parts changes and adjustments it was just the nature of the beast…. 5 and timing is 36 @ 3000. A carburetor is the part of an automobile that blends air and fuel at the proper ratio to allow for internal combustion in the engine. Engine starts, then races for a few seconds and then dies. Car runs pretty good every place other then off idle tip in. 086) and at 5200 elev. (power circuit for off-idle function), and secondary main. Easy Fix for Jeep 258 Carter BBD Idle Problem. Other then a slight hesitation when you stomp on it, it's running good. 015" clearance mentioned in carb instructions is supposed to be at WOT, so the pump diaphragm and linkage isn't bottomed out and making excessive friction on the pump cam and throttle lever so it won't hang at WOT. The only modification performed on the carburetor was to set the idle mixture and idle speed. I think your Edelbrock carb is an updated copy of a Cater AFB and Edelbrock should have a tuning kit available for it. thats why i purchased this model carb and size. This is on the new 401, with summit 8601 cam and 9. "I successfully installed my Edelbrock 1409 onto my M360. Let me start off by saying this is not a Holley Vs Edelbrock thread. Vacuum is 10 at idle. Car runs pretty good every place other then off idle tip in. I'm not sure that what you describe is a function of the carb itself or how well it was rebuilt and tuned. Keep it level -- fuel remains inside and can leak out. 130"), brass float and sufficient idle/off idle fuel for your engine. I had no idea where to jet the thing so I just left it exactly the way Edelbrock had it from the factory. If the engine either hesitates or stalls upon acceleration due to the carburetor, the carburetor's accelerator pump nozzle may need to be cleaned or the secondary throttle plates may not be closing all of the way. My first thought on the idle speed variation might be a vacuum leak. Take that 24 tune, which is 1 step rich in cruise mode, Most people do two things to try to correct this both cause the problem to get worseeither they richen the idle mixture or they increase the accelerator pump shot. Has a Michigan Motorz partial engine package including 1409 carb, cast iron 4 bbl intake ( allegedly a cast iron copy of Edelbrock performer- they grind the manufacturers name of them), thunder bolt v ignition. Ever since I got my 1406 carb installed, its had a hesitation problem. kinda like it was breaking up off idle when driving. I have a Holley 600 vac sec. The Edelbrock carburetor uses jets and metering rods that control fuel flow based on throttle position and intake manifold vacuum. ok im wondering how do i set the idle mixtuer screws on an edelbrock performer carburetor like how much do i turn the screws and how do i set them idling or dead help please the eal is i have hesitation when i try to go and black smoke comes out wen i take off it hesitates is how i know its the idle mixture some 1 show more ok im wondering. If you're having problems with your idle the first thing to look for is air leaks. I swapped that motor out for a 400 small block with a stock cam and put my intake carb and headers on it and when in gear if I mashed on it it would stumble and then clear out and fly. We test for vacuum leaks, flooding, bleed clogs, etc. Carbureted 302 Off-idle Stumble 5. Adjusting these correctly are essential to the carburetor's idle and off idle performance. Or you may not be pulling a good enough vac. The air valves already opened fully also. My guess is that it's pretty much the same for the big XR. The bikes front tire climbs up all the time. 1970 440 stock manifold with edelbrock performer 1407 carb stock exhaust manifolds Comp Cam -4 hydraulic flat tappet. Performer Series Carburetor. 6 exhaust valve,torker intake,headers and a mild cam, 727 with 3000 stall and 3. Stock: 10-12* or maybe even less. An idle system will have an idle jet/restriction that must be changed to supply the desired fuel mixture for idle and off idle engine demands. Virginia St. thats why i changed the squirter nozzle to a bigger size because it seems like its not getting enough fuel when there is no vacuum. A community for fans of the classic Dodge Charger. We bought a reman Quadrajet Carburetor online with an electronic choke. Factory 1406 comes with YELLOW springs. vaccum line to the distributor clamped off (and a cap on the. I think your Edelbrock carb is an updated copy of a Cater AFB and Edelbrock should have a tuning kit available for it. I had a 850 Demon on it before, but it was always running to rich all of the time and was hard to start and you had to let the car run for about 15 minutes to warm it up enough for it run okay, becaues it did not have a choke. To cure this condition either slightly undo all four idle-mixture adjusting screws to enrich the system or enlarge the idle-feed restrictors in the metering blocks. I am posting this so that someone might avoid the week of headaches I had trying to get rid of an off idle stumble on my '64 Galaxie. 600 cfm edelebrock carb (#1406) edelbrock performer cam edelbrock performer intake Mopar performance ignition hooker headers Jegs dual exhuast with magnaflow mufflers A904 tranny with b&m shift kit Lokar kickdown linkage It runs OK, but I have a problem with the off-idle throttle response. (stock engine shouldn't need nozzle changes but not impossible). In other words, when I accelerate from 8-900 rpm's, when going through 1100 the engine will stumble. The Racer Walsh 2. The 600 cfm is absolutely fine for the 305. I had that setup on the chevy with a built 402 (slightly undercarbed, perhaps) and it was bearable but noticeable. To me it was not a 300 dollar upgrade. Using an AFR (air fuel ratio) gauge you can see this, the AFR gauge will show the lean condition just off idle and often up to 2000rpm. A computer is adjusting the idle speed, based on complex calculations. For your fuel issue, I strongly recommend removing your carburetor and inspecting the idle transfer slot adjustment as set. new thumpr cam - wont idle below 1k Engine already has an edelbrock 4b carb and performer intake. I had tinkered and tinkered with the Edelbrock 1806 carb for almost a year, way too long. Good Garage Scheme offers tips and advice if you need a car repair. Stiffer springs pull the metering rods up out of the jets quicker when vacuum drops (when you step on the throttle). Best carb for offroad. Increasing the idle jets in the metering block solves this issue. This question was recently asked by one of our customers. Edelbrock 1403 (500 cfm) still sporting what appears to be factory calibration. Car and Truck Carburetors. Just run Edelbrock on the daily drive stuff. start with the basics. and may run a little rich. I have some ideas, either the carb (edelbrock 650cfm) is screwing with me, like a blown accelerator pump or something. I am not particularly proud of this "fix" but it did actually resolve the problem, so I decided to share all but one of the photos. Next I pulled the sec. Adjust the Gas / Idle Mixture Screws on Your Edelbrock Carburetor Chris Ingrassia. Tried jetting, different metering rods and springs to get it to be the same as the 1405, but still didn't run right. Calibrating idle mixture on an Edelbrock carburetor is controlled by equally adjusting the two screws at the front of the carburetor. To narrow it down, tap the roll pin out of the accelerator pump lever by using a small pin punch or a small finish nail. INTAKE MANIFOLD and CARBURETOR I ended up with a non-EGR Edelbrock Performer manifold which I did some modifications too. I do have the wrong intake for the street but no matter what i did to this carb it would still bog from the start. I have had many problems sense I went to a pumper Carburetor on my XR650R. Most everything else from the factory comes ORANGE springs. Also for: Performer 1413, Performer 1412, Performer 1411, Performer 1409, Performer 1407, Performer 1410, Performer 1406,. Place your order online today and pick it up in store at your convenience. I pulled the carb off of the engine to make sure I set the AV spring tension right. Virginia St. accessible on the top of the Edelbrock. Yeah, looks like that's the way to go. When I originally set up my linkage I backed off bolt idle screw until the throttle plates where closed and put my linkage on from there, then used the front idle screw only. ©2010 Edelbrock LLC. Also, you may want to record your calibration settings in the table below and keep it with your vehicle records. So through the winter months of '96-'97 I pulled off the old carb/intake, the GM double hump 1. 098 jet and a 075 x 047 metering rod. It has very little or no effect on off idle and larger throttle openings. I have an edelbrock 1406 series electric choke, 600 cfm carb on my sbc350 and I have always had hesitation issues with it if you accelerate hard. There is one more adjustment that is possible if changing the discharge rate does not cure your engine's off-idle stumble. 5 Pounds Vacuum Test and get 17 to 19 inches All that said, I still have erratic idle (fluctuates +/- 300 RPM) and a bog or stumble mid-range. Occasionally, the carburetor's idle jet will become clogged with dirt, which will cause the hesitation or stall. I cured a hesitation on an Edelbrock 1406 by going to a bigger accelerator pump nozzle.