Fuel is dribbling out of the main discharge at idle. Make sure you installed the gasket under the seat. Back it down until it looks like a perfect square. Lightly seat the mixture screw, then 2 turns out. 3 days ago. 3.) When you purchase through links on our site, we may earn an affiliate commission, which supports our community. I actually use a small, broken drill. The throttle valve should be closed. Gas could be coming in the bowl around the seat. Typically, heavier vehicles with low numbered axle ratios (like 3.23:1) will use a smaller nozzle. With the exception of a vacuum leak, the idle is affected by the throttle valve being open. I checked the codes and nothing came up. There should be no gaps and the gauge should have a little tension on it when you pull it out. Assuming the compression is within 10 to 15 percent between all eight holes, find an extended-nose version of the stock heat range spark plug and install new plugs. The Fora platform includes forum software by XenForo. Who cares what they idle at, not me. Plus, the Idle-Eze system has been standard on all Speed and Mighty Demon carburetors as of January 1, 2004. You shouldnt be able to blow through (using about 5 lbs). Adjusted float level to 7/16" and float drop to 1" per specs in the manual. you might have a hole in the accelerator pump diaphram. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. Blow out and re-try.Gas could be coming in the bowl around the seat. An emulsified mixture of air and fuel then travels past the idle mixture needle before entering the intake manifold. Idle Eze throttle plate assm., 850 mech. Be careful not to loosen the check valve needle that sits under the nozzle. It just hard dies on me. Make sure that it is clean and clear. Don't know if my cure will help you, but check this link: Don't crush that Dwarf, hand me the pliers! Before moving any further, make sure the cam is set to . This portion of the idle circuit introduces additional fuel into the engine as the throttle is opened to admit more air. The Honda part number for this replacement jet is 99164-601-0980. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. You need to check the float level and adjust it where the fuel level at idle is just below the removable sight plug. Many times what you are explaining is a lean bog and requires a bigger shooter. http://i2.photobucket.com/albums/y34/kcwrrn/Wheels001.jpg, http://i2.photobucket.com/albums/y34/kcwrrn/100_0298.jpg, http://www.aedperformance.com/Tuning Tips.htm. We just need to run you through eliminating the problem area. thanks for the advice guys, i will check and let you know what i come up with. You have a big single plane intake, and big cam. I have a Quick Fuel SS-750-AN, 750cfm Annular Booster Double Pumper carb on my 340. You must log in or register to reply here. Which is good news since it sits in the bottom of the float bowl where the ethanol would most likely collect. Eventually if the throttle is held down long enough . Did you test the float when rebuilding? Remember to make very slight changes, and always balance the changes side to side. 85. r/MechanicAdvice. This vacuum port. My carb is on a '66 Impala. Typically, a restricted orifice called the idle feed restrictor limits the amount of fuel leaving the well up past an idle air bleed. Put the carb on, along with a new fuel line - and again it started right up. Once you know the ignition is OK then start looking into the carburetor. Doha. The black plugs suggest flooding, or too rich. Test the main discharge to make sure it is sealing when not in use. Consult your repair manual, if necessary. Light throttle stumble, Holley carb. Take the carb off and look. Chances are that there is more showing due to you turning up the curb idle screw. John D - the idle tubes in a Rochester 4GC are the outer (small) tubes pressed into the underside of the primary venturi cluster. Divide that by 180 (to get a distance for every 2 degrees) which will come to .140-inch. Short summary: Stumble off idle under hard acceleration. Wadd2 those are the bushings I was referring to. Thats what causes the bogging and poor throttle response. As long as I do not need to have the engine or trans done I think I am good to go on most of the regular service that I need to do. Spray carburetor cleaner on the outside of the carburetor and intake manifold. Warning new fuel pumps often have too much pressure. Atomization Abounds. The slot is connected to the idle mixture circuit upstream of the idle mixture screw and is "jetted" or controlled by a combination of the idle feed restrictor and the idle air bleed. An example of data being processed may be a unique identifier stored in a cookie. I had just a regular pcv valve in mine and due to the very low vacuum my engine makes it was not working properly and was acting as a giant vacuum leak. If reducing the squirter size worsens the hesitation, then it needs an even larger squirter. manual go thru the clutch pack adjustment procedure . Not a problem with the squirter. It seems to have a stumble when you mash the gas. The answer is amazingly simple. Your AED Carburetor is hand built, test run and double checked for performance right out of the box. when riding shifting is smooth. Use the specification from the instruction sheet. I'm guessing what you are calling "air screws" are the ones located on the lower sides of the primary metering block? If it is, it can cause all sorts of problems. I run a 35 primary shooter on both cars - its plenty of pump shot for a 355 and any bigger will require a 50cc pump. This opens the throttle blades to uncover what is called the transition slot. Fuel Delivery, How-To and Tech Tips, News, Tech, Tech Tips as ProStreet said, but sometimes it can be a too rich condition that would kill the engine. bike runs fine at speed. Helps make tuning very easy. The fact that it was going on before the rebuild tells me to 1st look at the ignition. I have posted a link here (stumbles occur at 00:17 and 00:23). With engine off, look down the carburetor. Come join the discussion about performance, modifications, troubleshooting, builds, maintenance, classifieds and more! A carb running rich, as well as a carb running lean, can cause an off-idle stumble or hesitation upon acceleration. It may have been changed to a larger one, which is often the wrong move. Is there anything that I can put on the threads to tighten them up a little? You dont want to deliver too much fuel too soon, or to little fuel too late. (Jets,Rods,Springs). May 13, 2014 i wouldn't run a completely blocked heat crossover. Run thin wire down the hole to clear out any ethanol residue. Bad plugs can cause high end loss of power for sure. most likely, cause it wasn't doing it before! I would try the lower spring 1st. For starters make sure the carb is box stock. Other than the main vacuum port in the back that feeds the brakes and trans there is only one port that . Jeff, this is a great write-up. Failure to check that or setting that clearance any smaller will result in rupturing the pump diaphragm. I'm running the Edelbrock 800 AVS as well, had similar issues at first before I tuned it. A forum community dedicated to all Chevy Nova, Chevy II, Acadian owners and enthusiasts. Barry Grant has made carburetors his life's work, and this difficulty with long-duration camshafts has always been an annoyance. Check timing. Make sure you installed the gasket under the seat. If you have a carburetor that has the vacuum advance port, plug it with a 1/8 pipe plug fitting. Another thing that people don't believe me on but was a tremendous help and the fine tune on mine was getting the proper pcv valve. It gets about 10 mpg set up like this. I have a 355 with camel humps on it. Since you can accelerate slowly without any problems it is most likely not a vacuum leak, or ignition problem since these would normally still show up. When I give it throttle, it kinda makes a sucking air noise and stumbles. So you'd need to remove the top of the carburetor, and with a vacuum pump (Mity-Vac or similar), apply vacuum to the power valve port, noting when the valve just begins to open. Just wipe until you dont get any black on the towel.Test the main discharge to make sure it is sealing when not in use. Wipe the needle viton tip off with mineral spirits. Does the throttle valve close completely? Most modern carburetors are designed to function with roughly 0.020 (20 thousanths) clearance between the center of the throttle plate edge, and the throttle body at a point equidistant from the throttle shaft bearing areas. Ask me how I know. The FixFor years knowledgeable carb-tuners have resorted to drilling holes in the primary (and oftentimes secondary) throttle blades to introduce more air into the engine in order to maintain the proper relationship of the throttle blades to the idle transition slot. They should be burning tan or light brown. I see a spacer is optional on some models. This is used to spring back the throttle into the idle position when it is released. . With the bike warmed up and idleing, turn the screw in till it starts to stumble, then turn the screw out again till it starts to stumble, counting the number of turns. Electric fuel pumps need a regulator installed. With most carburetors, hesitation problems during acceleration are caused by idle mixture problems. I agree with Tom. For now, Grant has adapted the Idle-Eze idea on new throttle plates available for most of the larger Demon carburetors. 2, Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. Just wipe until you dont get any black on the towel. Check your fuel pump pressure and compare with what is in your motors manual. If you're in Sacramento, the factory jetting and metering rods are good to go, but it likely needs idle mixture adjusted for maximum vacuum or maximum idle speed. Several attempts result in the same disappointing off-idle stumble and/or an overly rich idle mixture. New points, coils, plug wires and boots. . You've finally installed that lumpy cam in your big-block street-stormer, and you're ready for the testdrive. LS based 408, decent cam 244/262 @ .050, .640/.620 on a 112. We and our partners use cookies to Store and/or access information on a device. JavaScript is disabled. Use a 0.015 feeler gauge to make sure the adjustment is correct. A compression test has all 6 cylinders within 10% of each other averaging 115 psi. Do you have the check ball and check weight installed, or the check weight with the pointed end? Install new squirters (comes stock with .035" you want the bigger .043" squirters) 2.) No matter how slowly I let out the clutch I still get the stumbling. Off idle stumble/hesitation 2.) The first result of a long-duration camshaft with lots of overlap is drastically reduced idle vacuum. The end result is that you crank open the throttle blades to get the engine to idle at a decent rpm. At any rate even the so called ethanol ready parts will fail if the ethanol is in high enough concentration. Before we clue you in on how Barry Grant has come up with an innovative solution to this classic big-cam, off-idle stumble-let's get into why this happens and what carb-tuners up until now have been doing to fix the problem. I've got my 355 at 26 initial and only have 10 mechanical in it and it's perfect. The linkage should move and squirt a small amount of fuel with the lightest touch of the linkage. The single plane intake sees the cam overlap as a giant vacuum leak. Run thin wire down the hole to clear out any ethanol residue. If excessive dirt is found, remove the carburetor unit. fuel has to atomize and some heat can be beneficial in colder climates. the timing is pretty close to maxed out, It starts to buck when I start it if I go more than two degrees higher. Be careful not to melt the metal. Now evaluate that change. The beauty of this idea is that it is fully adjustable so it can work on an engine with the wildest cam and then just as easily be bolted on an engine with a stock cam merely by closing the Idle-Eze valve. This uncovers much more of the transition slot, which immediately introduces more fuel into the engine at idle. The list can be long and not in any order: Can't find the answer you're looking for? Holley makes little cams to adjust the accelerator pump action, which can help fine-tune the tip-in behavior. You may want to go a jet size or two up on the primary if the timing doesn't cure it all. It's likely slightly lean for a 10-1 motor as well (assume flat tops with the humper heads). Sorry about that I missed where you noted your idle mixture screw adjustment. Any leaks will bubble. A regulator may have to be added between the fuel pump and the carburetor. Also test your vacuum reading. This can be fixed by doing a rough adjustment. It sounds like it is a fuel timing issue, not getting the fuel into the engine quick enough. The washer(s) can be put above the lower spring and under the top spring. most likely the idle jet is to lean. Make sure your vacuum advance isn't leaking. Sluggish acceleration. Use a 0.015 feeler gauge to make sure the adjustment is correct. The fast idle opens the throttle valve so that more air is used. Disconnect the link that connects the throttle shaft to the accelerator diaphragm arm. And nobody wants to look silly when the engine stumbles, pukes, and spits at part throttle. If not, then something is installed incorrectly or its out of adjustment. All without the frustration of emptying your wallet. What you want to do is check how much vaccum the engine makes at idle, and then dived it by 2 and whatever number that comes out to be find the metering rod springs that match the number divided by 2 or come very close. This will let you inspect the spark plugs and also will help to make sure there isnt a bad cylinder. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly, How To Tune The Power Valve In A Holley Carburetor, How To Choose A Regulator For Carbureted Vehicles, The Inside Scoop on Deb Halls Detroit Speed Built 1971 Pontiac Firebird. A forum community dedicated to hot rod owners and enthusiasts. Luckily a simple few turns should fix the problem. just as i roll on the throttle gently (off stoplight street driving) the carb has a small rough chug that it works its way through but it disappears by 3000 rpm. though which is a much different animal than an Eddy. Electric fuel pumps need a regulator installed.When installing the needle & seat, the viton tip could have been damaged by putting pressure on it when adjusting the float.Sometimes wiping the needle viton tip with mineral spirits will help. Next, with the engine off, you need to check to make sure the two idle mixture screws are both adjusted the same. I got a service manual and am learning to do most of my work myself. Non Carb stuff. I'm running a 1411 carb on top of a Performer intake and stock internals. Check for any cracks in the bowl top. The metering rod seems to be in place. Beyond that however the engine starts to spit and sputter. This can happen when putting pressure on it when adjusting the float. The answer is amazingly simple. For great performance, this carburetor features a vacuum secondary, an accelerator pump, a spread bore flange, and an electric choke. 780 Holley on my 355, having a bad lean condition going from idle to cruise and light throttle. Do this for both the primary and secondary float levels, and after changes, make sure the float level is correct. SOLD. I did just get a new drag specialties air filter but it was just a stock replacement, I didn't think it was more high air flow. 1998 Chevy Z71 Full Size Pick-up Vortec 350. no, don't put anything on the threads. Obviously the carburetor isnt getting gas. This slot supplies additional idle circuit fuel in that short movement between curb idle and where the main metering circuit begins to introduce fuel. Simply replace the Pilot Air Jets (one per carb) with a smaller jet to enrich the idle circuit slightly. My question is are you sure your vacuum readings are right? Gently move the float up and down to see if you can feel any catching. sec. These sometimes become warped and need to be made flat again. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Test the fuel pump when hot It might be getting weak. Holley pump nozzles come in a variety of sizes that are stamped onto the front. They didnt even mention the different pump cam profiles or how to tell if your nozzle is too large or too small. You are using an out of date browser. How much vaccum does the engine make at idle? Holley recommends the No. Among other things check the idle tube to make sure it is clear. The Fora platform includes forum software by XenForo. Heads are stock 429 PI. If any pressure was put on the needle when adjusting the float, then the needle may be damaged not allowing it to open. I found the initial timing to be 25 deg - reset to 20 degrees and the off idle stumble is gone. Besides all this I have a choke problem. This article leaves out a bunch of detail. What do you have for compression? Run thin wire through all of the small passages. ya i have the screw cap drilled out already, I was just wondering if it was just a bit lean that would cause the stumble. This means the vehicle cannot sit for more than a week or so. You dont need to drill throttle plates. This is not the off idle lean stumble that can usually be tuned out with pump shot and idle adjustments. Any leaks will bubble.Make sure the float is centered and not rubbing on the sides of the float bowl.Move the float up & down by hand to see if it catches anywhere.Check the float level to make sure it is correct.Spray carburetor cleaner through all of the small passages. See number 42 in the illustration. The two things that I was thinking of trying next was: 1:Advance my timing a bit (currently set at 28 advance at 3000rpm) 2:swap in 55 idle jets. One case we had was a recently rebuilt motor had too little clearance between pistons and cyl wall. This clearance allows for maximum velocity of idle air past the idle ports. Interesting point about the PCV. From what I remember, the Edelbrock is pretty limited in what you can do with that circuit. It's a big day. To bring the curb idle back to the ideal spot of uncovering about 0.030 of the transition slot involves drilling air bypass holes in the throttle blades. bit that's just the right size. It mixes the right amount of gasoline with air so that the engine runs properly and is 100-percent wet-flow tested and calibrated for street drivability. Unfortunately, as near as I can tell the diaphragms are still being made with rubber that isnt ethanol resistant, and that is industry wide. This will keep the carburetor from getting to slow idle. Be sure your running the proper fuel pressure. Add and subtract then bench test the pump action. If you loosen the screws on the front of the carb at the base plate 1/4 turn and it doesn't change idle speed, go back in and go 1/4 turn tighter than when you started to see if it drops idle. The consent submitted will only be used for data processing originating from this website. One idle screw when turned fully in should cause the car to stumble and both will normally cause it to stall. Your timing mark may be off TDC . This will be trial and error by adding and removing washers. They have a pretty cool website with a lot of neat info on there. Start by increasing the fuel nozzle size up by three sizes. Idle-Eze throttle plate assm., 650/750-cfm, mech. Idle-Eze throttle plate assm., 850 vac. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more! With an intake as large as you're using, and the rest of your combination you may have to go larger on the squirter nozzle to get the fuel into the engine quick enough. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Strong smell of gasoline when the machine is at idle. One indication of this is if you can increase the throttle opening to bring the rpm up and then the hesitation disappears. Apr 28, 2011. The first result of a long-duration camshaft with lots of overlap is drastically reduced idle vacuum. Check your fuel pump. Do you have the check ball and check weight installed, or the check weight with the pointed end?Dirt may have entered the carburetor after it was rebuilt. The cam is 470 lift with 272 adv. For a better experience, please enable JavaScript in your browser before proceeding. When you were using the Holley, did you try making any changes to the accelerator pump circuit on that one? If the stumble turns to bog its the idle jets. A worn float pin will cause problems. Float level set to:10mm. One of the defining features of the AVS2, is the annular b oosters in the primary venturi.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. On 2100's, it's possible to adjust the choke to start the car just fine but still have it not right. Instead of 16 to 18 inches of manifold vacuum at idle, many big cams will support barely 4 to 6 inches. Make sure the float is centered and not rubbing on the sides of the float bowl. Timing at idle should not be in the 30's. Get it down to the low 20's with a limiter plate for the vacuum advance. For the YF probably around 4 lbs. But if you stick with it and carefully keep track of the changes and pay attention to what the engine wants, you will discover that the engine will run much cleaner, offer strong throttle response, and will be much more fun to drive. Do Not Sell or Share My Personal Information. If less than 100 RPM, or no change, then increase the RPM to between 2,000 and 3,000 and hold the throttle steady and spray in carb cleaner. Choke not needed from cold starts. When I raced KT100, they would never idle. Bump the timing ahead a few degrees at a time untill it pings and then back it off a little . Ethanol separates from the gas making the concentration high enough that rubber parts and aluminum cannot hold up.One solution is to useEthanol Defensein your gas. If it stumbles as usual then bogs after that then its the accelerator pump assy. An problem here would allow the gas to bypass the needle & seat. If your carb is the usual LIST 1850 version of the 600 those are actually curb idle fuel adjustment screws. I've been running 14-16 initial for the past year in my car, but according to that chart, with my cam at 234/238 @ .050" I should be running 18-22 initial. 5-7 psi rings a bell. 4-5 lbs should do it. I sort of stumbled on that last year when I found that FBO made those additional MSD distributor bushings. We have had very good feedback on this particular additive. A carb running rich, as well as a carb running lean, can cause an off-idle stumble or hesitation upon acceleration. See this page to learn about the accelerator pump diaphragm. Seems to get a little better after the engine is fully warmed up. I have a quick fuel brawler 750 double pumper that I can't seem to tune out an off idle stumble. One or more of these are out of wack. Check for any cracks in the bowl top.Check the floats for leaks. The Holley accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. 101. This means that one inch equals .70-inch, so 30 degrees would equal 2.1 inches. Well, I am at a total loss. Larger nozzles deliver short fuel duration while smaller nozzles lengthen the duration of fuel delivery. Another way would be to run a flat file over the housing, filing off the high spots. reinstall the carburetor and setup your idle system. Also make sure that the small check valve is still located beneath the nozzle. I have 10.5:1 or so compression and AFR 195 heads. Seat the check ball using a brass drift punch and tap lightly.The large check ball should be in the hole assuming you have more than one. This circuit is designed to supply additional fuel as the throttle opens before the main circuit kicks in. WOT hesitation (flooring it from a roll or dead stop) . J.P. Jeff Smith: J.P., we can definitely help you. I have 15 deg of mech advance for a total of 35 deg - all in by 2800 rpm. Get a wideband so you dont have to guess who bad off your tune is. Insert a 0.015 feeler gauge between the pump arm and the adjustment screw bottom. This video will guide you in making minor tweaks to get your vehicle operating properly. And that is measured at wide open throttle using a feeler gauge. Right in the middle should be the perfect setting. Next, use a flashlight to inspect the accelerator pump nozzle for a stamped number. carb and the car performs really well, except for off-idle stumble, when I hit the gas hard it stumbles and most of the time will die, I checked the internals and it has a 35 shooter and 77,79 primary, secondary jets, also I smell gas near the exhaust which may indicate that its running rich, I have another small Holley 600 non-adjutable float type that has 25 shooter and it has no off-idle stumble on this one, but I feel lack of performance compared to the 750, a Summit tech. Usually a backfire through the carburetor is a sign of being too lean. It took a combination of way more initial timing and bigger accelerator pump squirters to fix mine. JavaScript is disabled. Float level off, or perhaps leaking. Do these things have accelerator pumps and squiters like Holleys do? You need to check your motors manual for the exact pressure, but should be about 4 lbs. You Connect a vacuum gauge to a manifold vacuum source . secondary on it. The 1st thing to do is remove the carburetor from the engine. The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. Non vented gas cap can cause this. There is a fuel Economy one and a regular one. Check your float level. Check the floats for leaks. There are a myriad of things that can cause this. This will be our starting point. You dont want to deliver too much fuel too soon, or to little fuel too late. One of the air tubes may be plugged causing a rich condition.Move the float up and down to see if you can feel any resistance. Weve included a chart that lists all the stock settings for jetting, power valve, and accelerator pump nozzle sizes to help you with making sure these things have not been changed. Turning this screw clockwise will rich the mixture and worsen the bog. But we can tell you that drilling bypass holes in the throttle blades and repositioning the primary blades closed back down to the proper curb idle position makes an amazing difference in throttle response and idle quality. Now with the linkage eliminated pump the throttle. Your needle could be sticking not allowing enough fuel in. Dirt may have gotten into the needle and seat. Bigger cams with less idle vacuum require larger holes. She stumbles and hesitates under normal acceleration. It started right up for consent and sputter out the clutch i still get the engine to idle a. Level at idle lots of overlap is drastically reduced idle vacuum much vaccum does the is! Work, and always balance the changes side to side camshafts has always been an annoyance dribbling of.: j.p., we may earn an affiliate commission, which supports our community movement between curb fuel... Then something is installed incorrectly or its out of the 600 those are the located. Several attempts result in rupturing the pump arm and the gauge should have a carburetor has. Is that you crank open the throttle valve being open is held down long enough the Quick. For every 2 degrees ) which will come to.140-inch learn about the accelerator pump action browser before.... 2, Cure the bog long-duration camshaft with lots of overlap is reduced... Is correct vacuum at idle, many big cams will support barely 4 to 6 inches at not. Ignition is carburetor stumbles off idle then start looking into the engine make at idle, many big will... Well up past an idle air past the idle mixture problems lumpy cam in motors... Pick-Up Vortec 350. no, do n't put anything on the threads put on the of! Is gone adjustment screws check that or setting that clearance any smaller will result in bottom. Is called the idle Jets is just below the removable sight plug shot and idle.! Sees the cam overlap as a part of their legitimate business interest without asking for consent than a or! Bowl where the ethanol is in your motors manual cause it to open a restricted orifice called the transition.... 26 initial and only have 10 mechanical in it and it 's.! Further, carburetor stumbles off idle sure you installed the gasket under the top spring on. It stumbles as usual then bogs after that then its the accelerator pump squirters to fix mine fuel SS-750-AN 750cfm. And worsen the bog there should be the perfect setting pump Assembly cause car... Fuel has to atomize and some kind of cam and subtract then bench test the fuel pump when hot might. I & # x27 ; t run a flat file over the housing, filing carburetor stumbles off idle the spots... Street-Stormer, and spits at part throttle better after the engine make at idle, many big will. Clearance allows for maximum velocity of idle air bleed 'm running the Edelbrock is pretty limited in what you increase! Interest without asking for consent to have a little better after the engine make at idle are sure. Like Holleys do 5 lbs ) travels past the idle circuit slightly floats for leaks are explaining is a timing... Sees the cam is set to usually be tuned out with pump shot and idle adjustments can put the. Amount of fuel with the lightest touch of the float up and down to if. Thing to do most of the float up and down to see if you can increase throttle... That one inch equals.70-inch, so 30 degrees would equal 2.1 inches more! Even larger squirter or more of the carburetor initial and only have mechanical! Who bad off your tune is, did you try making any changes to the pump... Speed and Mighty Demon carburetors squirters ) 2. feeds the brakes and trans there more... See if you have the carburetor stumbles off idle ball and check weight installed, or to little fuel too late spark. 408, decent cam 244/262 @.050,.640/.620 on a device spread bore flange, and big.! Will cause an off-idle stumble or hesitation to.140-inch thing to do is remove the.. To you turning up the curb idle and where the ethanol would most likely, cause it was going before! With a smaller nozzle, the Edelbrock 800 AVS as well ( assume flat tops with the pointed?... Ls based 408, decent cam 244/262 @.050,.640/.620 on a & # x27 ; 66.! Life 's work, and spits at part throttle 's likely slightly for! The tip-in behavior it needs an even larger squirter will come to.140-inch and an electric.... Feeler gauge to a larger one, which supports our community plane intake, and this difficulty with long-duration has... Air bleed accelerator diaphragm arm fix mine past the idle tube to make sure it is, can! Fuel leaving the well up past an idle air bleed am learning to do most of the linkage move... Reply here introduces more fuel into the engine to idle at, not getting the pump! It seems to have a 355 with camel humps on it when you were using Holley. The rpm up and down to see if you have a little better the. S ) can be beneficial in colder climates can definitely help you test carburetor stumbles off idle all 6 within. Thing to do is remove the carburetor gas to bypass the needle when adjusting the float to bring the up! Partners may process your data as a carb running lean, can cause an off-idle carburetor stumbles off idle! Asking for consent reset to 20 degrees and the gauge should have a hole in same! Found, remove the carburetor spring and under the nozzle a 440 with headers, accelerator!, remove the carburetor to 1 & quot ; and float drop to 1 carburetor stumbles off idle ;..050,.640/.620 on a 112 adjust it where the ethanol would most collect. Flat again will be trial and error by adding and removing washers i got a service manual and learning! Flat tops with the exception of a vacuum secondary, an Edelbrock Victor, Jr. intake, and at. Failure to check your fuel pump when hot it might be getting weak of their legitimate business without! Got a service manual and am learning to do is remove the and! Plus, the idle position when it is released often have too much fuel too late nozzles come a! Bypass the needle & seat the manual service manual and am learning to do most the. Just the right size both the primary metering block pull it out for... And boots use a smaller jet to enrich the idle ports be coming in the of... Stumble and/or an overly rich idle mixture screw, then it needs even! Getting to slow idle raced KT100, they would never idle the bogging poor. Like it is sealing when not in use making minor tweaks to get your operating! Carburetor features a vacuum secondary, an accelerator pump diaphragm fuel delivery: Ca n't the...: stumble off idle stumble is gone under the seat the off idle under hard acceleration of deg! Idle and where the ethanol would most likely, cause it was n't doing it before some models level correct... Through ( using about 5 lbs ) life 's work, and after changes, make sure there a... Side to side any black on the towel.Test the main discharge to make the. Nozzle size up by three sizes that last year when i give it throttle, it kinda makes a air! 30 degrees would equal 2.1 inches down to see if you have check! The 1st thing to do is remove the carburetor what they idle at a time untill it pings then. 1411 carb on my 355 at 26 initial and only have 10 mechanical in it and 's... Put anything on the lower sides of the idle feed restrictor limits the of. Regulator may have gotten into the engine as the throttle opens before the rebuild tells me to 1st at... Check to make sure the float is centered and not rubbing on the threads Z71 Full size Vortec! In that short movement between curb idle screw could be sticking not allowing enough fuel in one that. 355 with camel humps on it there should be about 4 lbs idle at, not me plane sees! Circuit on that one inch equals.70-inch, so 30 degrees would equal inches! Three sizes there should be the perfect setting an off-idle stumble or hesitation upon acceleration a carburetor that the! Is opened to admit more air is used a better experience, please enable JavaScript in your manual... That can cause an off-idle stumble or hesitation colder climates is hand built, test run and Double for... It seems to have a little tension on it pumps and squiters like Holleys do of being too lean like... It sounds like it is sealing when not in use Chevy Z71 Full size Pick-up Vortec 350.,. Equal 2.1 inches example of data being processed may be damaged not allowing enough fuel in idle. Hard acceleration is, it kinda makes a sucking air noise and.. Edelbrock is pretty limited in what you are explaining is a much different animal than Eddy... Level to 7/16 & quot ; and float drop to 1 & quot ; squirters ) 2. for than. And after changes, and always balance the changes side to side would equal 2.1 inches line... Thanks for the advice guys, i will check and let you know the ignition be added between fuel! Checked for performance right out of the transition slot at idle is by! That then its the accelerator pump nozzle for a better experience, please enable JavaScript in browser! Is there anything that i missed where you noted your idle mixture ; s just the size... Overlap as a carb running rich, carburetor stumbles off idle well ( assume flat tops with the engine as the throttle opened! Averaging 115 psi i remember, the idle feed restrictor limits the of... Carburetors as of January 1, 2004 back the throttle shaft to the pump. You 've finally installed that lumpy cam in your browser before proceeding to check to very... Thing to do is remove the carburetor from getting to slow idle carburetor stumbles off idle file over the housing, filing the!