Holley Accelerator Pump Cam Adjustment

How-to adjust the accelerator pump on Holley carburetors to avoid stumbling and hesitation upon acceleration. HOLLEY WHITE 30cc ACCELERATOR PUMP CAM #218, AED BG DEMON GRANT QFT CARBS See more like this. Since the pump seems functional then I agree that either there's too big a shot initially on tip-in or the secondaries are opening too fast. Jets for a lean condition. Starting a cold engine mostly depends on the actual temperature of the engine and the volume of the carburetor's accelerator pump squirt! Clearly, a Holley double-pumper with the big "50 cc" accelerator pumps is going to squirt a lot more fuel than a single-accelerator-pump Quadrajet or AFB. Cam "lift" directly affects the accelerator pump stroke and, therefore, pump capacity. Packaging should be the same as what is found in a retail store, unless the item is handmade or was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag. To adjust, bend fast idle cam link. The cam is preset at the factory. The backfire was more of a burp than the BOOMs I had been getting, so I think I'm on the right track. If the pump is initially adjusted to. Description Accelerator Pump Cam Assortment. With some circle track and road race carbs it is desirable to nearly eliminate the accelerator pump function because the only need is for a little bit of squirt to start a cold engine and get past letting the clutch out. It had too much tension on the pump lever and was starting out already in the stroke of the pump when the peddle was pressed. You can adjust the position of the pump cam. A couple of issues I've seen are : the accelerator pump cam arm adjusted incorrectly{ too far down } and consequently reducing the "pump shot " - lever down on the diaphragm and reducing it's volume. The #1 & #2 refers to the holes in the throttle lever for the screw that attaches the cams, positions 1 and 2. most Items ship next day. 040) nozzle or larger. Holley 350 Carb Cam Adjustment - posted in Engine: Hi guys my standard 202 engine with a 350 Holley recently had a flat spot, putting your foot down the engine would choke out and possibly stall. The adjusting screw holds tension from a spring so if you loosen the locking screw without holding the adjusting screw it will unwind like a window blind and you'll have to start over again from zero tension (which is another story). Engines that have more load generally require more initial pump shot while combinations with less load (e. This extra fuel prevents a severe lean-out in the fuel/air mixture that would otherwise occur. pump cam/pump arm, to correct “off corner” stumbling issues. The easiest and most common is the accelerator pump linkage. 031˝ squirter and a “pink cam” (Ole’s p/n. 2 barrel carbs are rated at 3 inches of vacuum and 4 bbl carbs are rated at 1. Assuming the distributor is OK, turn your attention to the accelerator pump circuit. The Holley type accelerator pump system consists of three main components: the pump diaphragm, the pump cam, and the pump nozzle (a. They include cams that have a different shape or profile to give different results. Holley recommends going up in 3 size intervals. Any slack will cause it to hesitate. If the stumble doesn't go away I agree with adjusting the accelerator pump shot. If it's not a strong stream, or it is late in the throttle range then you need to look at your pump. if he's willing to work with accelerator pump cams, pump. i rebuilt the carb and added new floats and jets and adjusted everything. Remove the air cleaner. If I adjust it so that there is. There are two tuning parameters to the accelerator pump circuit: Pump Cam and Discharge Nozzle. If it has actually been some time considering that you have actually taken a look at any brand-new cars, after that you may be in for a pleasant shock when you see the current technology. As the name implies, the accelerator pump provides additional fuel upon acceleration of the engine, while the primary circuit catches up to demand. The choke butterfly should be fully open, as the engine is warm. 5 Touch Screen LCD facilitates ‘laptop -free’ tuning changes to help optimize mileage, drivability, and performance. Re: Holley accelerator cam and nozzle questions May 28th, 2013, 04:53 PM I put 2 little washers on the adjustment bolt of my 670 right under the hole from the arm, it seems to make the contact with the pump arm better,more exact since its kinda sloppy,I used the green pump cam in the #1 hole and a 31 squirter ,works good now. Holley also supplies a wide range of accelerator pump cam profiles that allow the pump discharge rate to be tailored to the engine. For more information, visit www. 5% CO while the high boost pressure hot cam cruise mixture is 3% CO. If I hit the accelerator half way, it really hesitates. 086 inch for cams with 204 to 210 degrees of duration at 0. By the way, changing the pump cam requires readjustment of the free play. pump cam/pump arm, to correct "off corner" stumbling issues. How-to adjust the accelerator pump on Holley carburetors to avoid stumbling and hesitation upon acceleration. I have mine set to about 900 RPM. My cam and engnine was a lot more radical, bigger cam, etc. For some engines, lengthening the pump shot by putting the rod in the top hole (the hole closest to the carb body) is enough to solve a stumble. You want external float adjustment buy a quality aftermarket carb like a Quickfuel and you can have external float adjustments. With some circle track and road race carbs it is desirable to nearly eliminate the accelerator pump function because the only need is for a little bit of squirt to start a cold engine and get past letting the clutch out. It will help you identify the different components of your carb and the various vacuum and fuel fittings. If the stumble doesn't go away I agree with adjusting the accelerator pump shot. Accelerator pump cams come in various sizes and are color coded and number coded by Holley. I would like to improve a slight bog at WOT. This is something I have never been able to wrap my mind around. Tips include: How to check for the clearance between the accelerator pump diaphragm arm & operating lever; how-to select the correct accelerator pump nozzle size, and accelerator pump cam selection and installation. On Dominator-style carbs, the pump capacity is 50 cc for ten strokes. Install the pump connector link in the outer hole of the pump arm with the ends extending away from the counter-shaft arm. Each cam has a different ramp or profile to give different results. set allows the attachment of a 1/4" fastener to the 10/32" diameter hole found in the throttle linkage plate of Holley four barrel carbs. A few websites say to adjust the accelerator pumpshot, but you may also have to replace the pump discharge nozzle. needle valve 137 Fuel valve seat o-ring seal 12 Solenoid assembly 75 Pump check ball weight 138 Sec. Tips include: How to check for the clearance between the accelerator pump diaphragm arm & operating lever; how-to select the correct accelerator pump nozzle size, and accelerator pump cam. I'm working on my accelerator pump shot and wanted some opinions on whether I'm headed in the right direction with my tuning. pump cam/pump arm, to correct “off corner” stumbling issues. My favorite tuning tool for carbs is a wide band O2 sensor. The key is to have no slop in the accelerator pump system at starting line RPM, so that the pump shot is not "used up" below that RPM. It is very easy to test the function of the accelerator pump. Pump gas Pontiac 463 with a Quick Fuel Q950 on a 2" tapered spacer and single plane intake. This will extend the length and give the system some preload for an instant. It is a nylon. 089 for cams between 210 and 216 degrees of duration, and a maximum of 0. You 1st want to be sure the adjustment to the pump arm is such that when you press on the throttle, the pump starts to move right away. - Answered by a verified Classic Car Mechanic. The accelerator pump system provides an instantaneous “shot” of extra fuel in the main venturis as the throttle plates open. holley 3310-c 4 speed trans 3:50 gears vaccum about 15 at idle Issues: 1. Click to expand. Accelerator pumps come with a cam adjustment slot for controlling the timing of the accelerator pump and sit right behind the "1, 2" adjustment screw. Holley offers an assortment of different pump cams, each with uniquely. A recent teardown has exposed a wear area where the arm contacts the pump cam. Should the cam arm make the pump open all the way? Or is there a reason why the cam arm stops before the pump is all the way open? Sorry for all the questions but this about the last of the holley I still don't get. You should see a good shot of fuel shoot in two streams from the pump. A few websites say to adjust the accelerator pumpshot, but you may also have to replace the pump discharge nozzle. Accelerator Pump Levers - Carburetor Parts & Kits for Rochester, Carter, Holley, Edelbrock, Ford Motorcraft QJet, 4G, 2G, Mercarb Marine, AFB, AVS Thermo-Quad Carburetors. Internal pump passage in metering block equipped with a tunable bleed off for further tuning of accelerator pump; Factory machined accessory mounting hole for easy addition of adjustable primary throttle stop. A couple of issues I've seen are : the accelerator pump cam arm adjusted incorrectly{ too far down } and consequently reducing the "pump shot " - lever down on the diaphragm and reducing it's volume. If the mixture adjustment that I now have does not solve the problem, then I may also try changing the cam position to no. Carb Sizing. You 1st want to be sure the adjustment to the pump arm is such that when you press on the throttle, the pump starts to move right away. Today I'm going to take a couple of moments to talk about how to properly adjust the accelerator pump arm on a Holley carburetor. 015" clearance between screw and pump arm. - Answered by a verified Classic Car Mechanic. Adjusting the Accelerator Pump Stroke for Seasonal or Climatic Changes. pump system. Accelerator pump cams come in various sizes and are color coded and number coded by Holley. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. Accelerator pump not delivering the fuel shot fast enough. Classic Industries offers a wide selection of 1969 Dodge Charger parts, including 1969 Dodge Charger interior parts and soft trim, 1969 Dodge Charger exterior sheet metal, 1969 Dodge Charger moldings, 1969 Dodge Charger emblems, 1969 Dodge Charger weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. Find Holley Carb Screws on sale here with the largest choice of Holley Carb Screws anywhere online. Of course, the approved adjustment may have changed due to daylight savings time, metric system, CE directives, or such. Before changing the position, take a look at down the carburetor and make sure fuel squirts from the nozzle the instant you move the throttle. 043 squirters linkage in "rich" hole. Re-set idle and then use the vacuum gage to adjust the carb as others have said. Observe the pump jet in the carburetor, and with your hand, work the carburetor throttle to the wide-open position. It starts right up now. Classic Industries offers a wide selection of 1969 Dodge Charger parts, including 1969 Dodge Charger interior parts and soft trim, 1969 Dodge Charger exterior sheet metal, 1969 Dodge Charger moldings, 1969 Dodge Charger emblems, 1969 Dodge Charger weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. com/webapp/wcs/stores Tailor Accelerator Pump Performance. engine build By Grant Warner. By the way, changing the pump cam requires readjustment of the free play. Pump cam kits can be purchased to change the rate in which the accelerator pump will ramp in the additional fuel. Holley 750 Vac Secondary Accelerator pump Cam; Page 3 of 3 First 1 2 3. fuel level check plug 13 Cam follower retainer 76 Pump disch. The pump cam, a little plastic, color-coded part located on the throttle shaft with a single screw, will determine the total volume of the pump shot. Holley 30CC Accelerator Pump Arm 20-114 Features and. If the engine does not catch, with the choke plate still held open, pump the throttle two/three times. There may be multiple numbers, but the important one is the LIST number. Properly tune the accelerator pump circuits for your street, drag, or circle track vehicle. Holley offers an assortment ofdifferent pump cams, each with uniquely different lift and. How To Adjust The Accelerator Pump On Holley Carburetors - YouTube in this engine tech article HOT ROD compares the five best-selling Comp Cams camshafts for GM. 8cc too much fuel? I am having trouble adjusting the injection quantity of the accelerator pumps on my PMO carburetors (new installation), I initially measured each barrel and I get close to exactly. The cams have different shaped ramps that the arm from the accelerator pump rides on. The pump is built into the top plate of the Street Demon, as opposed to the bottom side of the fuel bowls like on the traditional Holley. Check accelerator pump Carn to ensure cam retaining screw is positioned in Specified hole in throttle lever. Since it's got a Holley carb I assume it's the 3 cylinder version of the 2000. Based on those posts it would seem that a lot of the Holley 2300 2bbl marine carbs seem to have the 50cc pump installed. With some circle track and road race carbs it is desirable to nearly eliminate the accelerator pump function because the only need is for a little bit of squirt to start a cold engine and get past letting the clutch out. Any ideas? (Holley 650 carb, holley intake, world product heads, 4x4 comp cam, bord 40 over). Try going down to a 24 shooter and see if that fixes the problem. The easiest and most common is the accelerator pump linkage. Although rarely necessary, the bigger pump can be installed on a 4150-style carb by using Holley’s conversion kit (PN 20-11). fuel level check plug 13 Cam follower retainer 76 Pump disch. We couldn't see the latter interference readily. I have a hesitation with the same carb, I adjusted my accelerator pump to the next point to spray more fuel it reduced the hesitation but it still there. Adjust if necessary. My driveline is entirely stock, save for the stock carb (which ran like crap no matter what) that I replaced with a Holley 0-80457S. also, try a higher idle speed and a different pump cam setting. Stick you mug up there and look at the squirt I'd say it's the pump cam or an old pump diaphragm, Or just needs a good cleaning. YEARONE Classic Car Parts for American Muscle Cars | Barracuda Cuda Challenger Charger Chevelle Road Runner Camaro Super Bee Dart Duster Valiant Firebird GTO Cutlass 442 Mustang Nova GM Truck Skylark GS Monte Carlo El Camino Mopar Chevy. The first adjustment to check is the clearance between the pump operating lever and the pump diaphragm cover's arm, at wide open throttle. I watched Holley's video on how to adjust the pump arm, and I'm just verifying this is the correct procedure: Open throttle wide open (does this need to be done on the vehicle, or can I do it on the bench?) Depress pump arm completely; Turn adjustment screw until. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. Pump cam kits can be purchased to change the rate in which the accelerator pump will ramp in the additional fuel. did it get better or worse? The engine is talking to you, it’s telling want it wants, if it got worse it’s still rich. Holley 1904 The accelerating pump stroke can be adjusted for seasonal or climatic changes by changing the position of the pump link in the throttle lever. Adjust the accelerator pump linkage. Until the book comes in, I was wondering if anyone knows where I can find out how to decode the color codes of the accelerator pump cams. Fits all Holley ; style carburetors. 015" clearance at wide open throttle (WOT). I watched Holley's video on how to adjust the pump arm, and I'm just verifying this is the correct procedure: Open throttle wide open (does this need to be done on the vehicle, or can I do it on the bench?) Depress pump arm completely; Turn adjustment screw until. 015˝ of clearance to exist between the pump spring adjusting screw and the pump diaphragm arm at WOT. The lever on the pump acts like it dosent want to move much, when i pull the throttle it just compresses the spring on the engagement arm and dosent hardly actuate the pump. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. The easiest and most common is the accelerator pump linkage. maintain the relatively higher idle setting. A 650 carb on a 358 cubic inch engine will seldom see 1. I had some success with that. Once a pump nozzle size selection has been made the accelerator pump system can be further tailored with the pump cam. Ramp profile or shape controls the "timing" of the shot. The #1 & #2 refers to the holes in the throttle lever for the screw that attaches the cams, positions 1 and 2. Should the cam arm make the pump open all the way? Or is there a reason why the cam arm stops before the pump is all the way open? Sorry for all the questions but this about the last of the holley I still don't get. 025 accelerator pump nozzle-Quick Fuel Technologies secondary diaphragm housing I got it used and rebuilt it when I rebuilt my engine ~5 or 6 years ago. After messing around with all the pump cams i had (pink, orange, and green)i have found that the accelerator pump adjustment bolt and spring was set too tight from the factory. If the pump is initially adjusted to. The guy had a holley 4 barrel carb bolted to the 2 barrel intake. i've never personally adjusted a 4150 carb that liked more than a 1 full turn on each meter plate screw, but i use a vaccum gauge when i set em under the carb. By the way, changing the pump cam requires readjustment of the free play. Its only on a good bite at the line and if I stay in it that it studders, stumbles. 089 for cams between 210 and 216 degrees of duration, and a maximum of 0. In addition to accelerator pump size, getting the right pump cam is critical to optimized tuning of your carb. The idle mixture is generally 1 to 1 1/2 turns out and both should be the same. 042" nozzles on both pumps. For proper adjustment, there should be zero clearance on this arm with the throttle arm closed (idle. Decrease the size. On Dominator-style carbs, the pump capacity is 50 cc for ten strokes. If you have the stock pump cam (off white in color if I remember right) then the WOT procedure is correct and there shouldn't be any gap, or slack between the two arms at idle. it idles fine and after the bog it runs ok. Then it gets better. Pump cam kits can be purchased to change the rate in which the accelerator pump will ramp in the additional fuel. HOLLEY WHITE 30cc ACCELERATOR PUMP CAM #218, AED BG DEMON GRANT QFT CARBS See more like this. 15: Vacuum advance connection. The accelerator pump circuit is responsible for providing smooth engine-climb when the throttle is quickly opened, and is as important for performance as it is for drivability. The WOT way is technically correct but some pump cam profiles don't play well adjusted like that. In addition to accelerator pump size, getting the right pump cam is critical to optimized tuning of your carb. The accelerator pump system provides an instantaneous "shot" of extra fuel in the main venturis as the throttle plates open. Im working on the accelerator pump adjustment on a Holley 750 DP that I am rebuilding. Accelerator pumps come with a cam adjustment slot for controlling the timing of the accelerator pump and sit right behind the "1, 2" adjustment screw. Holley Carb Accelerator Pump Cam Selection & Installation Tutorial Overview http://www. Holleys allow easy adjustment to circuits like the accelerator pump. The discharge nozzle, or "shooter," is available in. Accelerator pump cams on some carburetors might have three positions and adjust in the same manner. Changing the cams. There's also a new secondary pump cam lever to provide for a positive throttle stop on the secondary side. The Holley accelerator pump assembly that consist of the pump diaphragm, pump cam and pump nozzle. There are six areas you can modify, BASIC FUEL,. 5 power valve-green accelerator pump cam-. maintain the relatively higher idle setting. 2 position. and best way to adjust 4 idle air screws on same carb. So i decided to rebuild the 4 barrel holley thats on it. If the engine does not catch, with the choke plate still held open, pump the throttle two/three times. I would like to improve a slight bog at WOT. Accelerator Pump Lever Adjustment Do not forget about the accelerator pump lever adjustment. Tech Tip #3. 5 Touch Screen LCD facilitates ‘laptop -free’ tuning changes to help optimize mileage, drivability, and performance. These accelerator pump tuning kits by Holley are composed of a selection of accelerator pump hardware components, including pump diaphragms, pump nozzles, pump cams, and related parts. If the car blubbers initially then picks up it might need a pump cam adjustment. Holley 30 CC Accelerator Pump Return Spring (Heavy) Holley 30 CC Accelerator Pump Return Spring (Light) Holley 30 CC GFLT Accelerator Pump Diaphragm - (Alcohol) Holley 30 cc Metal Pump Arm Assembly Holley 50 CC Accelerator Pump Return Spring Holley 50 cc Metal Pump Arm Assembly Holley Pump Arm Stud Holley Pump Cam Kit. For some engines, lengthening the pump shot by putting the rod in the top hole (the hole closest to the carb body) is enough to solve a stumble. Accelerator pumps come with a cam adjustment slot for controlling the timing of the accelerator pump and sit right behind the "1, 2" adjustment screw. Cam "lift" directly affects the accelerator pump stroke and, therefore, pump capacity. and FAST takes care of the rest. The pump lever spring travel must also be adjusted to allow. Holley 4150(750 dbl pumper) with tunnel ram. YEARONE Classic Car Parts for American Muscle Cars | Barracuda Cuda Challenger Charger Chevelle Road Runner Camaro Super Bee Dart Duster Valiant Firebird GTO Cutlass 442 Mustang Nova GM Truck Skylark GS Monte Carlo El Camino Mopar Chevy. If it does, you have too much fuel. Order Carburetor Accelerator Pumps for your vehicle and pick it up in store—make your purchase, find a store near you, and get directions. Pump cam kits can be purchased to change the rate in which the accelerator pump will ramp in the additional fuel. When functioning properly, the full depression of the accelerator pedal will release the choke spring tension being held by the fast-idle cam and screw, while also providing a shot of fuel into the manifold by the accelerator pump. 5 power valve-green accelerator pump cam-. 1 instead of no. high stall torque converters) can benefit from less pump shot. It will meet your needs and deliver great quality at an affordable cost. The stock accelerator pump on a 4150-style carb has a capacity of 30 cc for ten strokes of the pump. cam up to where the adjustment screw. Works much better, yet still has a slight hessitation, but not all of the time. This is the carburetor system that is most responsible for having good, crisp, off-idle throttle response. Hg or below. Pump arm adjustment and clearance should be checked and verified each and every time the pump cam and/or pu mp cam position is changed. My Holley tune up parts kit is even more extensive with air bleeds, metering block restrictors, power valve, jets, vacuum secondary springs, accelerator pump cams, and the discharge nozzles. if he's willing to work with accelerator pump cams, pump. I'm working on my accelerator pump shot and wanted some opinions on whether I'm headed in the right direction with my tuning. I was told you can bend the accelerator pump linkage rod to get a faster shot to get rid of a mild bog. I had an old 4 barrel intake laying around. Although application needs vary, Murphy recommends 0. There needs to be NO slack in it whatsoever- it needs to squirt instantly at the slightest throttle opening. The cam is preset at the factory. BE (before ethanol) the neopreme pump would last maybe 3~5 years, while leather will last indefinitely. The system also uses various springs, cams, and diaphragm sizes to control the amount of fuel injected by virtue of the duration of the injection phase. The cams have different shaped ramps that the arm from the accelerator pump rides on. They include cams that have a different shape or profile to give different results. Holleys allow easy adjustment to circuits like the accelerator pump. The lever on the pump acts like it dosent want to move much, when i pull the throttle it just compresses the spring on the engagement arm and dosent hardly actuate the pump. Unfollow holley accelerator pump to stop getting updates on your eBay Feed. I am not sure how to get more shot from the pump cam. Straight from Holley: Accelerator pump shot relative to cam color from lightest to heaviest are as follows: White, Blue, Red, Orange, Black, Green, Pink & Brown. transmission bracket kit 20-121 700R-4 kickdown throttle arm 20-12 Accelerator pump cam assortment 20-122 Pro series secondary linkage 26-137 Secondary adjusting lever kit 34-39 Billet adjustable fuel log Model 4150™ features. Now is a good time to understand carb flow ratings. 015 extra movement of the pump arm so not to over stretch the pump diaphragm. Pumps fuel into the air stream, via the accelerator pump accumulator, during hard acceleration. The first adjustment to check is the clearance between the pump operating lever and the pump diaphragm cover's arm, at wide open throttle. 089 for cams between 210 and 216 degrees of duration, and a maximum of 0. ) bog with giving it slight gas while driving stutters, shutters, wants to die out, occasionally gives a small pop out of carb, I'm guessing this has to do with size of accelerator pump nozzle? right now has. 031˝ squirter and a “pink cam” (Ole’s p/n. The WOT way is technically correct but some pump cam profiles don't play well adjusted like that. Start the engine, and warm to normal operating temperature. The complete pump mechanism consists of an inlet check valve, an outlet spray nozzle, a diaphragm, three springs that move the diaphragm, and the pump lock valve. If you're up at 40 with a typical orange pump cam and it's still stumbling I'd first check your accelerator pump linkage adjustment. I'm thinking accelerator pump, but not sure. A steeply rising ramp shape will give a fast, heavy fuel shot right off idle. We use an accelerator pump upgrade kit on most Holley modular style carburetors that consists of a stronger duration spring, a 0. your's has 4. I wish I can see some one else adjust theres. Accelerator Pump Cam. The plastic cam on the throttle lever only affects the accelerator. 089 for cams between 210 and 216 degrees of duration, and a maximum of 0. Accelerator Pumps. Accelerator pumps come with a cam adjustment slot for controlling the timing of the accelerator pump and sit right behind the "1, 2" adjustment screw. Demon Race Demon. Holley 2300 if it matters. Install the pump connector link in the outer hole of the pump arm with the ends extending away from the counter-shaft arm. Do not soak the choke pull-off or fast idle cam in the carb cleaner. com/webapp/wcs/stores Tailor Accelerator Pump Performance. Re: Holley accelerator cam and nozzle questions May 30th, 2013, 11:49 AM I had a 4v cleveland on the street with a stock iron intake and a number of different carbs, it wasn't a big cam by todays standards, flat tappet hydraulic street / strip grind - didn't require any exotic valve train hardware - stock rockers, etc. This adjustment is referred to as the. However, location of the pump is not. The Holley type accelerator pump system consists of three main components: the pump diaphragm, the pump cam, and the pump nozzle (a. Custom tailor accelerator pump timing to your specific engine needs. Accelerator pump not delivering the fuel shot fast enough. By the way, changing the pump cam requires readjustment of the free play. fuel level check plug 13 Cam follower retainer 76 Pump disch. Hg, "85" indicates 8. 31 in it not sure if I need to go smaller or bigger. A very common problem on Demons and Holleys is the maladjustment of this accelerator pump arm. The accelerator pump circuit(s) in a Holley carburetor acts to smooth the transition between the idle circuit and the main circuit. 50cc pump cams. Prevent engine sputtering by learning how to properly tune your Holley-style four-barrel carburetor's accelerator pump. 20/22r with Holley 350 2bl I've tried adjusting the carb and timing with not much success. How-to adjust the accelerator pump on Holley carburetors to avoid stumbling and hesitation upon acceleration. Proper accelerator pump adjustment helps in both street and strip applications. I don't get any fuel from the squirters until the throttle opens a bit. Just recently while going at low speed cruising and giving more gas to speed up, there is hesitation. nozzle check ball 139 Fuel level check plug gasket 14 Cam follower lever 77 Primary fuel bowl screw 140 Float retainer. Holley 30 CC Accelerator Pump Return Spring (Heavy) Holley 30 CC Accelerator Pump Return Spring (Light) Holley 30 CC GFLT Accelerator Pump Diaphragm - (Alcohol) Holley 30 cc Metal Pump Arm Assembly Holley 50 CC Accelerator Pump Return Spring Holley 50 cc Metal Pump Arm Assembly Holley Pump Arm Stud Holley Pump Cam Kit. The accelerator pump operating rod must be positioned in the proper holes of the accelerator pump lever and the throttle overtravel lever to assure contact pump travel. Performance is pretty much always better when the fuel is delivered from "in-circuit" as opposed to from an accelerator pump. Look for the highest vacuum you can get. like a bad accelerator pump. The plastic cam on the throttle lever only affects the accelerator. At 7 inches of vacuum the 350 carb is really flowing about 430-440 cfm. Accelerator pump cams come in various sizes and are color coded and number coded by Holley. Turning the screw clockwise will raise the RPM's and counter clockwise will lower the RPM's. I had to pour the carb cleaner in a large pot so all of the larger parts could soak. Unfollow holley accelerator pump to stop getting updates on your eBay Feed. Now is a good time to understand carb flow ratings. If you have the stock pump cam (off white in color if I remember right) then the WOT procedure is correct and there shouldn't be any gap, or slack between the two arms at idle. NOTE: The Of the pump Cam the accelerator pump stroke. correct accelerator pump cam for your specific application based on how aggressive the accelerator cam profile is. The ideal accelerator pump shot is with the least amount of fuel that allows the engine to accelerate cleanly under all conditions. Shut it off and pull over, pull a plug and read it. The pump cam, a little plastic, color-coded part located on the throttle shaft with a single screw, will determine the total volume of the pump shot. Holley carb adjustment question: I was wondering if anyone knows what the proper setting should be for an accelerator pump spring (I think that’s what it’s called. The carb is a 750 cfm Holley 3310 4 bbl with vacuum secondaries. The accelerator pump arm and spring are stock, and the accelerator pump cam is the pink one. ACCELERATOR PUMP CAMS AND SHOOTERS Accelerator pump cams come in various sizes and are color coded and number coded by Holley. For oval track use, the pump lever should be adjusted so there is no play in the pump linkage when he throttle is closed. The idle mixture is generally 1 to 1 1/2 turns out and both should be the same. This adjustment is referred to as the. Part# 120077. How To Adjust The Accelerator Pump On Holley Carburetors - YouTube in this engine tech article HOT ROD compares the five best-selling Comp Cams camshafts for GM. I need to get this sorted out before I can break in my new engine. Just started converting my bike from carburetor to EFI using FAST EZ EFI system, everything fits fine, plan to fire it up tomorrow or Monday. 1 instead of no. Holley 4-Barrel Carburetors - Camaro, Chevelle, Chevrolet, Corvette, Chevy II / Nova 1964-67 Holley Components - 4160 Series (Single Fuel Inlet 585 CFM 275 to 390 HP) 1965-72 Holley Components - 4150 Series (Dual Fuel Inlet 780-855 CFM 375 to 450 HP). The guy had a holley 4 barrel carb bolted to the 2 barrel intake. Replacement accelerator pump diaphragms for all Holley carbs. Would not go. Holley 1904 The accelerating pump stroke can be adjusted for seasonal or climatic changes by changing the position of the pump link in the throttle lever. Somewhere along the way it was determined that accelerator pumps could be made much cheaper with neopreme, rather than leather skirts. I have a Holley 2300 7448 350 CFM 2bbl Carb that has been modified to blow through using the hangar18 mods it has a Percy adjust-a-jet, and center-hung float bowl. For some engines, lengthening the pump shot by putting the rod in the top hole (the hole closest to the carb body) is enough to solve a stumble. Unfollow holley accelerator pump to stop getting updates on your eBay Feed. Jump to page: Adjusting Holley Accelerator Pump. 2) Choke linkage binding. transmission bracket kit 20-121 700R-4 kickdown throttle arm 20-12 Accelerator pump cam assortment 20-122 Pro series secondary linkage 26-137 Secondary adjusting lever kit 34-39 Billet adjustable fuel log Model 4150™ features. Holley provides a machined accessory-mounting hole that makes it easy to add an adjustable primary throttle stop. Includes 8 cams for 4150 four barrels and 2300 two barrels with 2 screws. Description Accelerator Pump Cam Assortment. Now is a good time to understand carb flow ratings. I'm trying to adjust the squirter. nozzle check ball 139 Fuel level check plug gasket 14 Cam follower lever 77 Primary fuel bowl screw 140 Float retainer. In this quick video, Tom Kise of Holley goes over how to properly adjust the accelerator pump system on one of the company's carburetors. If an engine stumbles two or three times after the driver steps into the throttle this usually indicates too much fuel and can be corrected by. There are six areas you can modify, BASIC FUEL,. HOLLEY WHITE 30cc ACCELERATOR PUMP CAM #218, AED BG DEMON GRANT QFT CARBS See more like this. I would like to improve a slight bog at WOT. Although Holley makes choosing carbs appear easy in the. This accelerator pump cam assortment kit allows you to tailor accelerator pump performance to the engine's actual requirements. The Holley’s accelerator pump system differs from others in that instead of bending a linkage or changing the linkage mounting hole position, Holley uses plastic cams on the throttle arm.