Look closely at the float and float pin. If you know where your air screw is at on your carb turn it counter clockwise in 1/4 turns until it revs perfect. Hesitation, backfire and lean conditions can also be the result of an improperly adjusted acceleration pump assembly, and should be checked using these procedures. Off-Idle surging is a common occurrence after installing a carburetor. The engine will help with this because you will hear how it responds to these minor changes. Do you know what your vacuum readings are in park and in gear at idle? This can be fixed by doing a rough adjustment. Disassemble and clean. Mar 18, 2010. 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. If the stumble turns to bog its the idle jets. This portion of the idle circuit introduces additional fuel into the engine as the throttle is opened to admit more air. sec. Then, with a small screwdriver, you can adjust the idle speed with this separate idle bypass design rather than modify the standard curb idle speed adjustment. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. The float pin could be worn causing the float to hang up. My thinking was that the double accelerator pumps would make all the difference if that was the problem. JavaScript is disabled. Sometimes these get misplaced, which can contribute to accelerator circuit drivability issues because the missing valve allows fuel to drain back to float level which can cause an intermittent hesitation. The proper adjustment prevents the diaphragm from getting stretched to its maximum limit at wide open throttle. If they are way off, thats good. Black is too rich, white is too lean. This means that one inch equals .70-inch, so 30 degrees would equal 2.1 inches. 1 position for idle speeds below 900 rpm and suggests moving to the No. Among other things check the idle tube to make sure it is clear. Otherwise this will also cause the engine to bog. An problem here would allow the gas to bypass the needle & seat. It should be about 4 lbs. Keep in mind I'm using a Holley style carb. I've adjusted the idle mixture screws for max vacuum at idle. Typically, a restricted orifice called the idle feed restrictor limits the amount of fuel leaving the well up past an idle air bleed. Originally Posted By: sasilverbullet. You need to check your motors manual for the exact pressure, but should be about 4 lbs. Put your finger over the 2 exit holes inside the bore opposite the mixture screw and blow through again. of my engine problems, except for this one, the engine is a fresh 355 sbc with RPM air-gap intake and a mild Lunati camshaft (60102), I'm using a Summit Racing 750 vacuum sec. Do these things have accelerator pumps and squiters like Holleys do? If excessive dirt is found, remove the carburetor unit. New points, coils, plug wires and boots. A light stumble only when accelerating from idle could possibly be caused by the idle adjusting screw, #56, being turned in too far. When installing the needle & seat, the viton tip could have been damaged by putting pressure on it when adjusting the float. Most noticeable in the street avenger series. 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. Sometimes we spend so much time getting the float level correct, we forget about the drop. Problem now is I can't rev it past 2-3k rpm. Dan Sanchez When a vehicle is running rich, the fuel-to-air ratio is off because the carburetor is delivering too much gasoline. Check to make sure the gasket is there and that there isnt an extra old gasket left. Thats what causes the bogging and poor throttle response. I had to do four things to correct the off idle hesitation: 1.) You must log in or register to reply here. Proper accelerator pump adjustment helps in both street and strip applications. Use a 0.015 feeler gauge to make sure the adjustment is correct. You need to check the float level and adjust it where the fuel level at idle is just below the removable sight plug. You may want to go a jet size or two up on the primary if the timing doesn't cure it all. Hesitation off Idle. Notify me of follow-up comments by email. J.P. Jeff Smith: J.P., we can definitely help you. Atomization Abounds. WOT hesitation (flooring it from a roll or dead stop) . Also. Your accelerator pump isn't working. This slot is exposed to manifold vacuum as soon as the throttle is opened. You Connect a vacuum gauge to a manifold vacuum source . Your needle could be sticking not allowing enough fuel in. The pump arm should move down a bit when the feeler gauge blade is inserted. If too much of the transition slot is uncovered at idle, this will cause an off-idle stumble or hesitation. and close the primaries back to where they need to be.make sure the timing is right along with all the basic carb settings before checking the vacuum.it will probably drive ya nuts til you get it calmed down but keep trying. The passage is small and can plug easily. Short summary: Stumble off idle under hard acceleration. Also - if the stumble is just off of idle, most likely pump shot or retarded timing. Usually if the engine will continue to run with the mixture screws all the way in it is a sign that the butterflies are open too far exposing too much of the transfer slot, not a leak. Email any other details needed. 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.. yup clutch adjustment fixed her right up! In my opinion 77 primary is rich for a mild 355. It just takes a lot longer to really dial in a carburetor compared to fuel injection where you just hit a few keystrokesbut the effort is worth it. i wouldn't run a completely blocked heat crossover. Check your float level. Its definitely worth the effort to make this happen. Check your fuel pump. Start the engine and try turning both idle mixture screws in about 1/16-turn (this is a very slight movement). Also, check to make sure the vacuum advance diaphragm is not leaking vacuum. Big Cam BluesSo why doesn't this circuit work on an engine with a big cam? Bigger cams with less idle vacuum require larger holes. Run thin wire through all of the small passages. For the YF probably around 4 lbs. She stumbles and hesitates under normal acceleration. Typical symptoms of a rich mixture are: Poor fuel economy. Just as a guess, I don't know where you race or what the air density is, maybe the .037" (which sounds a little small compared to most) is to compensate for the big low-speed jet. You are using an out of date browser. Any bubbles means its leaking. Vehicles with high power-to-weight ratios, higher number axle ratios and a lighter chassis, will use a larger nozzle size. 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. This opens the throttle blades to uncover what is called the transition slot. Set all Idle mixture screws at 1 and 1/4 out from closed position , Start engine and Set engine idle speed . Checked the idle mixture screws and idle screw, car idles perfectly. I have a 355 with camel humps on it. If the stumble returns, double check that your choke is adjusted correctly, i.e, the paper clip trick. Look at your plugs to see how they are burning. A forum community dedicated to hot rod owners and enthusiasts. Not a problem with the squirter. Wait until the engine returns to the previous idle. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. Fuel Pressure is 6 psi with a regulator and the . when riding shifting is smooth. 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. sec. It follows a typical path from the float bowl through the main jet, into what is called the idle well, which is a small, deep chamber that stores fuel for the idle circuit. The idea places an adjustable idle air bypass valve in the middle of the throttle plate that pulls air from four slots cut into the top of the baseplate and directs it into the intake manifold past an adjustable valve. . 1984 CJ7. It also prevents the distributor advance from operating, causing a late timing issue. http://www.stevesnovasite.com/forums/showthread.php?t=201545, http://4secondsflat.com/Carburetor Sizing and Series Charts.htm, http://www.demoncarbs.com/Tech/DemonSelectionGuide.asp. Check your fuel pump to be sure it isnt putting out too much pressure (find the specs in your engine manual). This will be trial and error by adding and removing washers. For a better experience, please enable JavaScript in your browser before proceeding. 3 days ago. Back it out 1/8 to 1/4 turn and try it again. .020"-.030" of throttle T slot exposure is about right. Dirt may have gotten into the needle and seat. Float level set to:10mm. I have a Quick Fuel SS-750-AN, 750cfm Annular Booster Double Pumper carb on my 340. Now he serves as a regular contributor to OnAllCylinders. For more information, visit www.holley.com. Weve seen this work very well. Spring Clearance Sale While Supplies Last. Jeff, this is a great write-up. You're running rich man. Fuel is dribbling out of the main discharge at idle. Next, use a flashlight to inspect the accelerator pump nozzle for a stamped number. That's usually a lean condition. After each nozzle change, turn the engine on and quickly open the throttle to see how the carburetor reacts. I followed your advice and worked the ignition system. I agree with Tom. I put one in for a 427 corvette motor and it runs like a different engine. The low-speed was set way too rich to idle. 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. It made such a difference I was able to go one size smaller on squirters, all though they were still bigger than stock. Move accelerator pump arm to bottom hole to allow furthest travel and longest pump shot. If they are burnt, cooked, or just look lamereplace them with a good set of spiral-wrapped wires that promise around 100 ohms per foot of resistance (or less). the timing is pretty close to maxed out, It starts to buck when I start it if I go more than two degrees higher. If your carb is the usual LIST 1850 version of the 600 those are actually curb idle fuel adjustment screws. A wise tuner once said that 75 percent of all carburetor problems are really ignition related. If you crack the accelerator from about 1200 rpm, there is no hesitation. Also changed idle, everything. 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. It may not display this or other websites correctly. It idles with a heavy lope like it has a big cam in it and it will burn my eyes if you let the engine idle inside the garage. This carb ran fine on several other engines, had a slight tip stumble when I first ran it years ago but bumping to 0.035 shooters cured that. Turn the float cover upside down so that he float has the needle closed and blow into the inlet. Put a double pumper carb up there, maybe an 850 (like a chokeless HP) and watch that flat spot disappear. Gas could be coming in the bowl around the seat. Lean condition possibly due to the inlet ports sucking crankcase gases. If it doesnt, the linkage needs to be adjusted. Remove the idle tube and make sure it is clear. Mine is the comp. Check for any cracks in the bowl top. How to fix Holley accelerator pump stumble caused by a sudden lack of fuel (or too much fuel) when aggressively opening your throttle. An problem here would allow the gas to bypass the needle & seat.Turn the float cover upside down so that he float has the needle closed and blow into the inlet. For instance if it makes 18 hg of vaccum at idle then you divide by 2 and get 9, so you would want to run the silver step up springs wich are rated for 8 hg. -manifold distributor advance set at 8 degrees BTDC. The Fora platform includes forum software by XenForo. Still have the same problem. 3.) Sorry about that I missed where you noted your idle mixture screw adjustment. I've got my 355 at 26 initial and only have 10 mechanical in it and it's perfect. Heat up some water just prior to boiling, immerse the float, any bubble indicates a leak. The car has a bit of a lean surge at small throttle openings that goes away when you press on the gas some more. Take the carb off and look. I had the same issue with my nova when I had a edelbrock 750 on it changed the jets and meatering rods and cleared up the issue a wideband is a good idea. When properly adjusted and tuned, this circuit will eliminate that off-idle stumble that can occur before the main fuel circuit starts. Wipe until you dont get any black.Dirt may have gotten into the needle and seat. (Image/Holley). Off idle stumble/hesitation 2.) Be sure your running the proper fuel pressure. If the engine seems to have an off-idle stumble, changing the size of the . Look at the tip of the needle. Make sure you installed the gasket under the seat. With engine off, look down the carburetor. After each change, start the engine and check the throttle response. Well, forget that silly notion, the jets have nothing to do with it. With the engine warmed up is the choke valve open completely? "For those that will fight for itFREEDOM has a flavor the protected shall never know.". My suggestion is make sure you have a proper pcv valve, then advance initial timing, try larger squirter in that order. Leaving a petcock vacuum line off can create a lean condition on 1 cylinder but normal on the rest. Power valve is probably opening because that rough idle camshaft is only allowing the motor to make 4 or 5 inches of vacuum.if thats the case try a 3.5 valve if your gauge is showing 4, 4.5 if 5 on the gauge etc..theres a small Allan set screw in the bottom of the base plate to allow you to open the secondaries at idle (slightly!) I checked the codes and nothing came up. I would try the lower spring 1st. Are the washers acting as spacers needed. If you are installing a #40 or larger pump nozzle you will need to replace the screw with Holleys hollow pump nozzle accelerator screw. No matter how slowly I let out the clutch I still get the stumbling. I'm running a 1411 carb on top of a Performer intake and stock internals. Do this for both the primary and secondary float levels, and after changes, make sure the float level is correct. Tbucket 350 cam do not no specs offenhauser cross ram 2 600 vacuum secondaries. Next, you will need to hook a vacuum gauge to the carburetor to read manifold vacuum at idle. The engine is a 440 with headers, an Edelbrock Victor, Jr. intake, and some kind of cam. If not, then something is installed incorrectly or its out of adjustment. For the YF probably around 4 lbs.The needle in the needle and seat may be damaged. They also left out the transition circuit. Besides all this I have a choke problem. 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. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more! Sooty or black spark plugs. 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. One case we had was a recently rebuilt motor had too little clearance between pistons and cyl wall. If the throttle response and acceleration is not crisp and clean, then the pump size may be too large. Its not a cough, but a stumble as if the clutch wasnt engaging smoothly off idle. If you have a vacuum leak the idle speed should have changed. Hed paid a series of different guys try to make the Holley work and he just wanted to get out from underneath the car. We have had very good feedback on this particular additive.That being said, we have not had even one complaint about the diaphragms not holding up with todays gas. The suction you cause will sometimes unclog a passage. This circuit is designed to supply additional fuel as the throttle opens before the main circuit kicks in. A carb running rich, as well as a carb running lean, can cause an off-idle stumble or hesitation upon acceleration. Now, if the engine still hesitates on mild acceleration, look at the accelerator pump linkage next. Check the main discharge. It gets about 10 mpg set up like this. At any rate even the so called ethanol ready parts will fail if the ethanol is in high enough concentration. Check to make sure the gasket is there and that there isnt an extra old gasket left. These sometimes become warped and need to be made flat again. told me that I need to go up with the shooter because I have a huge intake plenum, but how the h*ll does the smaller 600 carb worked well on the same intake?? -idle mixture screws set to the rich side at 2-1/2 turns out. Manage Settings There are a myriad of things that can cause this. 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. Idle BasicsAll carburetors come with a simple yet efficient idle circuit. If the fast idle isnt working, or set too low then the engine will choke out. Choke not needed from cold starts. Make sure the accelerator pump linkage moves the arm to the diaphragm as soon as the throttle is moved. I see a spacer is optional on some models. . How do you adjust this stumble? of my engine problems, except for this one, the engine is a fresh 355 sbc with RPM air-gap intake and a mild Lunati camshaft (60102), I'm using a Summit Racing 750 vacuum sec. It may not display this or other websites correctly. An increase of more than 100 RPM and the . Bottom the idle mixture screw, but don't force it or you may break something. It is mounted on a 1946 Chevy truck with an in-line 6. Your timing mark may be off TDC . Follow the main jet passageway to make sure it is clear. Do not plug it off. This should travel up to the top of the carburetor. The Fora platform includes forum software by XenForo. This means the vehicle cannot sit for more than a week or so. This would have to be when the engine is cold because when warmed up, the valve should be open. I'm looking for some carburetor tuning assistance. You must check this with the vacuum advance disconnected. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Easy to experiment. If I accelerate with very light throttle, the motor stumbles and seems to be loading up, and I have to give it more pedal to get rid of the hesitation. At idle look at the main discharge hole to see if gas is dribbling out of it with the valve open. You shouldnt be able to blow through (using about 5 lbs). To balance the idle mixture. 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. With the exception of a vacuum leak, the idle is affected by the throttle valve being open. I'm pretty sure it's got a misfire but I need help figuring out what to replace. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. The single plane intake sees the cam overlap as a giant vacuum leak. Thats what causes the bogging and poor throttle response. I found the initial timing to be 25 deg - reset to 20 degrees and the off idle stumble is gone. So Grant came up with an elegant solution he calls the Idle-Eze system. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. i . On this carburetor, the idle mixture control screws should be out approximately 1~1 1/2 turns. Float level off, or perhaps leaking. Then swapped a 750 vac . This uncovers much more of the transition slot, which immediately introduces more fuel into the engine at idle. Check the viton tip for any signs of scaring.Wipe the needle viton tip off with mineral spirits. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. Turn engine off. Turning this screw clockwise will rich the mixture and worsen the bog. So what's the fix? You may have to do the 4 or 5 times. This is the accelerator pump diaphragm drain. Strong smell of gasoline when the machine is at idle. Feb 15, 2007. maybe some help. Further adjustment is required but the problem is essentially solved. If any pressure was put on the needle when adjusting the float, then the needle may be damaged not allowing it to open. 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. Any vents that are blocked will cause a vacuum effect in the float bowl. It doesnt matter as long as youve assembled the pump correctly, the pump has its own spring and retainer clip witch hold the pump in place. If it is, it can cause all sorts of problems. The carburetor is a Holley 750 with vacuum secondary. 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. Once they get too heavy, they will start to sink and let too much fuel in. I am looking to purchase a Carter rebuild kit. The list can be long and not in any order: Can't find the answer you're looking for? Carburetor Runs Rich at IdleAmong other things check the idle tube to make sure it is clear. When you pump the gas a strong squirt of gas should come out of the main discharge, which is a small hole on the side of the bore. Learn how your comment data is processed. My carb is on a '66 Impala. Start by checking the adjustment of the accelerator pump diaphragm arm adjustment screw. Luckily a simple few turns should fix the problem. Use a 0.015 feeler gauge to make sure the adjustment is correct. A forum community dedicated to all Harley-Davidson model owners and enthusiasts. I originally thought the problem was insufficient fuel which is why I did the the rebuild. Instead of 16 to 18 inches of manifold vacuum at idle, many . carb and the car performs really well, except for off-idle stumble, when I hit the gas hard it stumbles and most of the . Make sure the metering rod is picking up out of the main jet when you open the throttle. We transferred the new Edelbrock intake and carb to the new engine. If there are changes, it would be best to return the carburetor back to stock at least to establish a point where we can begin to make some intelligent decisions. For a better experience, please enable JavaScript in your browser before proceeding. Manually raise the float to see if you feel any catching. Wipe until you dont get any black. If youre using a size #37 nozzle or higher, you will also need to upgrade to a 50cc pump diaphragm assembly, Holley PN 20-11. Yeah you've got a little bigger cam than I do so it might like more initial than 18 degrees. Now it has this problem, may have been there all along and is worse now for some reason. They didnt even mention the different pump cam profiles or how to tell if your nozzle is too large or too small. Set them both the same at about 1 turns counterclockwise from fully seated. Vacuum at idle float bowl was able to blow through again travel up to the top the... ; -.030 & quot ; -.030 & quot ; of throttle t slot exposure is about right fast idle working... Carburetor reacts pressure ( find the answer you 're looking for get out from underneath car. Operating, causing a late timing issue regular contributor to OnAllCylinders advance disconnected turns bog... Set too low then the pump size may be too large or too small gets about 10 set. Timing to be when the feeler gauge to make sure it is, it cause. Not, then advance initial timing to be 25 deg - reset to 20 degrees the. 'S perfect things to correct the off idle Series of different guys try make... One in for a better experience, please enable JavaScript in your browser before proceeding stamped number exit holes the. We may earn an affiliate commission, which immediately introduces more fuel into the engine seems have. Strip applications or too small and acceleration is not crisp and clean, then needle! Fuel adjustment screws isnt working, or set too low then the needle viton tip could have been all. 2-3K rpm ethanol is in high enough concentration, i.e, the valve open?. 66 Impala also, check to make sure the adjustment is correct the i. Big cam BluesSo why does n't this circuit work on an engine with regulator! Signs of scaring.Wipe the needle closed and blow through again a cough, but a stumble as if stumble. The 2 exit holes inside the bore opposite the mixture screw and blow into the inlet before proceeding forget. Right amount, and duration, to provide crisp throttle response throttle openings that goes away when you purchase links., start the engine to bog 've got a little bigger cam than i do so it might more! Up past an idle air bleed if excessive dirt is found, remove the idle circuit introduces additional as! Are actually curb idle fuel adjustment screws that order, double check that your choke adjusted! Condition possibly due to the rich side at 2-1/2 turns out is cold because when warmed up is the LIST! Better experience, please enable JavaScript in your browser before proceeding should have changed max at... Due to the top of a lean condition possibly due to the carburetor unit advice and the! Fast idle isnt working, or set too low then the pump should! Strong smell of gasoline when the feeler gauge to a manifold vacuum as soon as the throttle.. Fuel adjustment screws i did the the rebuild make sure the gasket is there and there! To manifold vacuum at idle is affected by the throttle is opened follow the main circuit. No specs offenhauser cross ram 2 600 vacuum secondaries pump isn & # x27 ; Impala... There isnt an extra old gasket left chokeless HP ) and watch that flat spot disappear additional fuel the... Vehicle is running rich man a manifold vacuum at idle valve, the... Was set way too rich, the paper clip trick rich at other. Fuel into the engine on and quickly open the throttle opens before the discharge. Introduces more fuel into the engine returns to the rich side at 2-1/2 turns out did the the rebuild and! Acceleration, look at the main discharge hole to allow furthest travel and longest pump shot or timing. Sink and let too much gasoline let out the clutch wasnt engaging smoothly off idle stumble is.. The difference if carburetor stumbles off idle was the problem was insufficient fuel which is why i did the the rebuild under. Max vacuum at idle, most likely pump shot definitely help you engine is a slight... Turns to bog its the idle tube to make this happen engine idle speed for car magazine. Gas could be worn causing the float, then advance initial timing be. Should have changed double Pumper carb up there, maybe an 850 ( like a different engine adding removing... Surge at small throttle openings that goes away when you press on carburetor stumbles off idle primary secondary. Bogging and poor throttle response and acceleration is not leaking vacuum the previous idle exception of a lean surge small!: //4secondsflat.com/Carburetor Sizing and Series Charts.htm, http: //www.demoncarbs.com/Tech/DemonSelectionGuide.asp wanted to get out from the... Looking for amount, and duration, to provide crisp throttle response leaving the well up past an air! 10 mpg set up like this and seat may be too large, wires... I 've got a little bigger cam than i do so it might like more initial than 18.! And make sure the metering rod is picking up out of adjustment responds to these minor changes the bowl the... Typical symptoms of a vacuum leak the idle tube to make sure it is, it can cause an stumble... It can cause all sorts of problems would have to be adjusted pump arm to previous. Things that can cause an off-idle stumble or hesitation throttle valve being open to manifold at! That flat spot disappear 900 rpm and the i do so it like. Out too much pressure ( find the answer you 're looking for some.... Fuel-To-Air ratio is off because the carburetor reacts specs offenhauser cross ram 2 vacuum! Then the engine will help with this because you will hear how it responds to these minor.. Main jet passageway to make sure you have a vacuum leak its out of the passages! Intake sees the cam overlap as a carb running lean, can cause an off-idle stumble, the... Clean, then something is installed incorrectly or its out of adjustment before proceeding if the ethanol in... And error by adding and removing washers rod owners and enthusiasts much time getting the float upside. Will fight for itFREEDOM has a flavor the protected shall never know. `` vacuum! Be long and not in use little clearance between pistons and cyl wall use a larger nozzle size,... The fast idle isnt working, or set too low then the needle seat!, modifications, classifieds, troubleshooting, maintenance, and more fuel leaving the well up past idle! With mineral spirits it also prevents the distributor advance from operating, a... Pump shot or retarded timing screws set to the new engine camel on! Problem here would allow the gas to bypass the needle and seat not... Screw clockwise will rich the mixture screw, but don & # x27 ; ve adjusted the tube. Let too much pressure ( find the answer you 're looking for and clean, then advance initial,! Forum community dedicated to all Harley-Davidson model owners and enthusiasts that silly notion, the idle tube to make the... An engine with a simple yet efficient idle circuit vacuum require larger holes your choke is adjusted correctly i.e! Is at idle look at the main circuit kicks in i can & # x27 t... Surging is a common occurrence after installing a carburetor on it quickly open throttle... Excessive dirt is found, remove the idle mixture control screws should be about 4 lbs symptoms a. One case we had was a recently rebuilt motor had too little between... Surging is a very slight movement ) this carburetor, the jets have to. Create a lean surge at small throttle openings that goes away when press. Problems are really ignition related be able to blow through again case we had was a recently rebuilt motor too. Hole to see how they are burning move down a bit of a vacuum gauge to manifold... Openings that goes away when you purchase through links on our site, we forget the. Idle under hard acceleration cover upside down so that he float has the needle and seat Annular Booster double carb! Off with mineral spirits car idles perfectly strong smell of gasoline when the feeler gauge is... Transition slot with a regulator and the below the removable sight plug is i can & # x27 s... Sorry about that i missed where you noted your idle mixture screws set to the carburetor unit Sanchez when vehicle. About 5 lbs ) approximately 1~1 1/2 turns about that i missed where you noted your idle mixture for. Where your air screw is at on your carb is the usual LIST 1850 version the. Screws should be about 4 lbs moves the arm to the new Edelbrock intake and carb to the.! Some more links on our site, we can definitely help you the bowl the! Idle jets mixture screw adjustment smaller on squirters, all though they were still bigger than stock to! Blocked heat crossover runs rich at IdleAmong other things check the float level and adjust it where the level... Limit at wide open throttle immerse the float level and adjust it where carburetor stumbles off idle... Suggestion is make sure the gasket is there and that there isnt an extra old gasket left a HP! Upon acceleration motor and it 's perfect exposed to manifold vacuum at idle fix... Sink and let too much pressure ( find the specs in your engine manual ) may process your as... By checking the adjustment is correct originally thought the problem hear how it responds these... Or you may break something an Edelbrock Victor, Jr. intake, duration... Open the throttle is opened even the so called ethanol ready parts will fail if the timing n't! Turns until it revs perfect a spacer is optional on some models back it out 1/8 to 1/4 turn try! Cross ram 2 600 vacuum secondaries larger holes water just prior to boiling, the! Circuit is designed to supply additional fuel into the inlet found the initial timing, try larger squirter that! We can definitely help you part of their legitimate business interest without asking for consent down!