Established since 1996, we perform high performance carburetor tuning, and rebuilding on any make or model vehicle. Inspect the carburetor venturies and manifold passages. 5 pounds of pump pressure by virtue of a 0. i was just wondering what sort of benefits there are from the conversion? i dont know much about carbies so any help is appreciated. I have a cosworth engine with huge. New Page History and development A carburetor was developed by Enrico Bernardi at the University of Padua in 1882, for his Motrice Pia , the first petrol combustion engine (one cylinder, 1,225 cc) prototyped on 5 August 1882. I have recently install a Weber 32/36 carbureator on my 1983 BMW 320i (e21) 1. beautiful truck, go to drive it and it is missing, and backfireing,hesitating, etc. The chap at CFS was really helpful. Weber carburetors have been seen as standard equipment on the finest racing and street machinery to come out of Europe for over three decades. Here’s something you don’t see every day, or, ever. I believe properly adjusted carbs will run well, so this discussion only applies to carbs that have been properly adjusted and STILL don't run smoothly. 8 cabrio running a weber carb. On a four-barrel carburetor, there is a primary side and a secondary side. Footage taken from Holley Carburetor Installation & Tuning DVD. Hi All- 77 MGB- Replaced my ZS carb with a Moss SU HIF44 carb. but still fully choked. I followed Pony Carbs timing instruction to the letter and the problem continues. And I had a flutter or stumble under hard acceleration around 3000 rpms. Brand new ones, right out of the box, will have strong hesitation on acceleration. There is hesitation if I step on it and low end power is sufferring a bit. I installed this kit on my '79 GL1000 and it's like having a whole new bike. a bit of a stumble in very light, low speed. The fulcm pivot point can be adjusted. Under accelaration it is fine? 84 22R, Weber carb Cadillac. 351 Cleveland Engine Induction Guide: Intake Manifold- Covers Engine Building and Performance Updgrades to the 351C, 351M, 400M Ford Cleveland Engine. This carburetor virtually eliminated the stumbling-on-acceleration problem except for a slight "blip" on sharp acceleration. The World's Largest Community of RX-7 Owners and Enthusiasts. Now that I'm caught up in the Weber carb world, I have a complete set of Holley. Second, when off-idle stumbles are present, they can be the result of something other than the acceleration circuit, so work on the stumble. ] never come out of the box clean or jetted perfectly for your engine. 1) Check for vacuum leak & repair. I had got a used carb at pull & save, and it worked great for a while, but it’s now got a hesitation. The Carter style carbs are my favorite,(Same as Edelbrock,Weber,Now Magneti Marelli is making them for Edelbrock). Please advise. The carb mount nuts take more torque than the assembly screws, of course. Engine wanted to "stumble" a bit when cold when throttle was applied. Mixers come in all shapes and sizes, depending on the engine size. Virtually any change imaginable can be performed without removing the carburetor from the manifold, and the most common changes may be performed in less than five minutes without removal of the airhorn (bowl cover). Find the user manual you need for your lawn and garden product and more at ManualsOnline. ( use tachometer) Now slowly turn the L speed mixture clockwise( lean) and note any changes, will speed up. 3) Accelerator pump nozzle has dirt in it. Make a donation to this forum! You choose the amount. 1964 Lotus 7 (series 2) NOT A REPLICA! This Lotus 7 serial number SB 1428 has been restored to a very high level. Found this last night when I was surfing the web for the YJ part that I had that got burned up. Do the same for. Manual adjustment of idle speed is NOT possible on modern vehicles. to do an inspection of a Tri carb for me. To check the accelerator pump: With the engine off remove the air. Before you can make any changes, you need to determine whether to change the cabin. The Edelbrock Performer Series Carburetor is designed to allow quick and easy changes to the metering. Never had much luck with the Holley. By adding NF Ultra Unleaded Race Fuel Concentrate to pump fuel, you are giving your vehicle a product that can out perform a lot of more expensive commercially available race fuels. The good news is that these can easily be replaced without carb removal. Slowly turn in untill the engine stumbles and then turn other direction until it stumbles agian. A carburetor is a device that sits on top of an intake manifold and has one basic job: to properly mix air and fuel for delivery into an engine. VW Carburetor Jetting Procedure. In 2015, Dave decided the best way to rebuild the Carter YF carburetor on his 1954 Jeep CJ-3B "Lil Willy" was to really understand how it worked, and then he undertook to make the lessons he learned available to everybody on the CJ-3B Bulletin Board. 7LX 1996 (total 320 hours), with mounted 4BBL Weber carburettor. Most people experiencing hesitation think, "put in bigger jets" right off the bat. This is a rundown of what I've learned from my own personal experiences with Dellorto carburetors on RX-7s. The coil had gone bad. Hesitation on Half Throttle but a couple things can affect weber smoothness in the beyond off-idle and not close to wide-open-throttle areas of driving. 7K ) Number of downloads: 18 It works. As for the timing,it was at 0*,so I retarded the dist. Mechanic friends also told me most likely a sticky accelerator pump. Hesitation, stalling, stumbling, flatspot, or deadspot during acceleration: Backfiring or spitback through carb. There are other functions not discussed here, but can be found elsewhere. DELLORTO 48 DHLA CARBURETORS. Occasionally, the carburetor's idle jet will become clogged with dirt, which will cause the hesitation or stall. 00 okay so in my 87 chevy suburban with a 5. Ill pull the solex off and give it a good clean, or would it be worth sticking a single webber 34ict on as i here so much about pict 34 cabs and 009 dizzy problems. html#post988816 1972 250 - Cold start and acceleration problems. The factory accelerator nozzle spray of most popular carburetors is a stream of fuel that is hard for the engine to atomize and combust, limiting the performance of your carburetor and engine. If not, then check the plugs. Please Note: Other than exact replacement OEM carburetors, all Mikuni Aftermarket Carburetors and Tuning Components are sold “As Is” for Off Road / Racing Use Only and are not intended or approved for use on vehicles operated on Public Roads or in Locations where applicable engine tampering and anti-pollution laws apply. Finally check for any vacuum. Electronic Ignition. The extra aggressiveness and punch of the Weber had highlighted a problem that I had been vaguely aware of for some time. 2) Reset timing. The internal pieces, starter valve and so on, might still be installed inside the carb, but they are of no function with the block off plate and can be. First, we need to figure out if you have the proper sized carburetor to begin with! Bigger is NOT necessarily better. Did the problem start after any modifications?. hesitation on. A carburetor will have an air screw or a fuel screw, one or the other but never both. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor, By Properly Adjusting The Accelerator Pump Assembly If your car or truck is equipped with a Holley four barrel carburetor and stumbles upon acceleration, more than likely the carburetor needs an adjustment to the accelerator pump assembly. Note: All DCOE carbs are not equal. com and affiliated sites. Runs great for about a half hour on the free way and then all of a sudden I get a little hesitation. B) Factory carburetors, especially in the emissions era, are undersized for the engine. The Cougar originally ran a 750 Race Demon, then upgraded to Weber Power Plates which made a huge difference for the tune. What's New 3 12 24 72. Some symptom’s of a lean fuel condition are: needing to adjust the idle too high, rough idle, hesitation or a stumble on acceleration, a flat spot at around 2500 RPM and/or surging at a constant RPM in. I found out the kit itself was kind of a running joke in the forums after I bought the thing and actually looked in the box and started to try to install it. If you need help with carburetor tuning or need help understanding carb operation leave a comment below. Found this last night when I was surfing the web for the YJ part that I had that got burned up. They can also cause erratic running that seems to mimic a mis-adjusted float, but worse. Maybe you've been lucky enough to get a ride in a Ferrari or a Weber carburetor 289 Cobra; if you have, chances are, it's a ride you've never forgotten!. Idle is smooth. It overshoots due to momentum. The value clearances have been set very carefully. So I recently purchased new weber 44 idf's. no gas will cause a bog or sputter and then a sudden pick up. 78 mm stroker 90. Do not depend on the factory delivered settings. To check the accelerator pump: With the engine off remove the air. I have a Weber carb on both my Shay & truck. The carb illustrated is a slightly modified version from that of the MGB, but will give you a good idea of how things are put together. 5:1 1400 RWHP E85 TT SBC, everywhere over 1800 RPM seems to be OK. I have a rebuilt 258 (<200 miles) a new weber 2 bbl and an HEI ignition. The homebuilder can manage this weakness in the carburetor by installing a heating device for the carburetor. Richen the mixture one hour on the carb and one half hour on the other so they both will be richened the same. Newer models required 2. Thanks to all for the suggestions I have received so far concerning my hesitation problem on the 'B ('79 engine, weber DGAV). Racer Brown was a licensed mechanical engineer and was once technical editor for hot rod magazine. I just rebuilt the carb and installed 170 air correctors, 140 main jets, 45 idle jets and F50 emulsion tubes. Tips on how to fix that dreaded Weber Flat Spot / Lean Hole? GoodVolks Community. The most economical dual carburetor setup available are dual ICT carburetors from EMPI or Weber. The acceleration pump jets compensate for this effect. A lean surge will feel like someone is moving the throttle, or you get a hesitation on light throttle acceleration). A "clunk" like hesitation when accelerating from a dead stop 2 Answers. Robert recommends a replacement jet – size #98. The good news is that these can easily be replaced without carb removal. Basically, i deduced that due to the extreme radii i had on the previous setup, i experienced a "hold back" or extreme hesitation when i applied acceleration. Hello again, While trying to set the carbs right we came accross the fact that accelerator jet wasnt doing much, because it stuttered when pumping the gas. Backfiring caused by internal carburetor problems is a result of a defective accelerator pump. be seen from the outside of the carb. The Weber DGV was originally designed for a 6-cylinder European Ford. I have recently install a Weber 32/36 carbureator on my 1983 BMW 320i (e21) 1. I've been trying to tune my Weber DGV around a slew of changes in my engine and exhaust system. Here's a little writeup I have done on Webers. Eating meat was credited with allowing humans to develop large brains. The truck has always run great, but I was driving on Saturday and suddenly developed a severe miss- almost a “buck”- plus lack of power/acceleration and inablity to use sudden throttle. Symptoms are truck idles and revs fine in park. As you state, gradual run up is fine but jumping on the throttle causes a stumble. 0L D-Jetronic motor I have today, both of my motors ran well and had their. Weber carburetors have been seen as standard equipment on the finest racing and street machinery to come out of Europe for over three decades. html#post988816 1972 250 - Cold start and acceleration problems. This Volvo has a B20 motor, which is the larger 2 liter version, runs strong and only has 140,xxx original miles. I am watching this post because I have a similar problem with my new 77 roadster. But I notice the last 10-15% of the throttle opening makes zero difference to acceleration. In Part 2, Demon Carburetion helps us identify a few more chief components of the modular, square-bore carburetor, acquaint you with common problems that can arise, and tell you how to prevent them. On my wagon, it started hard, stumbled on acceleration, and so on. It produces a richer fuel/air mixture when the engine is cold, then gradually makes the. Both sides are jetted differently. A carburetor (North American spelling), or carburettor (Commonwealth spelling), is a device that blends air and fuel (usually gasoline) for an internal combustion engine. MERCURY MERCRUISER MARINE ENGINES GM V6 262 CID (4. i had the carb tuned, accelerator pump replaced (which helped a bit as it was pretty much shot), new plugs/wires/dist cap and rotor, fresh oil. My questions are:-Would it be easier, more cost effective, and more powerful to get the aftermarket carb or convert it to fuel injectors?. Weber hesitation between 2800 and 3800 RPM If this is your first visit, be sure to check out the FAQ by clicking the link above. A very popular modification for kit car owners is the fitment of twin Weber DCOE or DCO/SP carburettors; these not only deliver the goods but also look very good. gday all, ive heard from a few people and numerous posts on the site that putting a webber 34 adm carbie on my 202 blue (currently with Varajet 2 carbie) would be a good move. The primary jet sound a little high from what I remember. In most cases the "hi" fuel screw will not have to be turned more than a one-quarter turn in either direction. This carburetor virtually eliminated the stumbling-on-acceleration problem except for a slight "blip" on sharp acceleration. Had a weber on before, worked really well, but took that off to put on a different truck. It is supposedly a 3k/4k kit so I guess it is already properly set-up for the application, or at least close to. After adding the 16% pulley it seems like It needs more fuel during normal acceleration. This banner text can have markup. seat of the pants part throttle to secondary acceleration tests. I have a 1996 boat with a 5. Carburetor Sizing. If the engine stumbles when given a sharp blip of the throttle, increase the pump jet size until the hesitation is gone. The Weber people make a simple, tune-able carb and expect you to educate your foot to its abbilities rather than bunch of add-ons. The homebuilder can manage this weakness in the carburetor by installing a heating device for the carburetor. This compares favorably with conventional carburetors, including Weber, which are die cast pot metal. Not sure what this will equate to, but I will find out tomorrow when I install the rebuilt carbs and do all the settings. A DEFECT IN THE CARBURETOR. I would suspect the stumble is occuring in the 2200-2500 rpm range yet not entirely based upon engine rpm and maybe a little more dependent on throttle placement versus engine vaccum. This is a rundown of what I've learned from my own personal experiences with Dellorto carburetors on RX-7s. At higher throttle settings, it just growls and loses power. Dave replaced the Pierburg carburetor with a rebuilt German 427-1 model that he bought from Keith. The Weber carbs are also supposed to be good for boost but the parts are not as readily available for tuning as the Holley. Tuning Dual Weber IDF Carbs on the VW Type 1 Engine A fact - [You must be registered and logged in to see this link. I have tinkered with the carb just a bit by increasing the primary jets to 72's and the secondaries to 70's. Ron, Usually when people talk about motors running lean, they are referring to the fuel/air ratio. This Weber carburetor will increase your torque and horsepower by up to 10%. Carbs have many tiny orifices that are not immediately visible. The variable choke (Venturi) allo~s an increase or decrease in choke. its been getting worse since. I had got a used carb at pull & save, and it worked great for a while, but it's now got a hesitation. It has always been recognized as the easiest and most affordable carb kit in terms of performance. So, given mechanical soundness, it is, just as you say for the majority of "types". Remove file tape from the lower intake manifold flange and the carburetor air horns. There are traditional ways of tuning such as timing acceleration runs and shutting off the engine at full throttle, then coasting to a stop and checking the plug deposits, but these are not very practical on public roads. It is a very crude compensation and not all that critical as to how accurate an individual pump stroke delivery is. here I'll present a problem that I have with my MERCRUISER 5. A DEFECT IN THE CARBURETOR. Since they designed a larger carburetor from scratch, the air entry and flow is much greater than the three barrel Weber. I changed it from a Carter AFB to a Edelbrock 1406. Last week I added a WMW 16% pulley package, with belt tensioner, belt and plugs. Another method (from SMI, IIRC): "Simply turn the screw DOWN (CW) 1/2 turn at a time until you experience a "lean surge". Have just refitted the Carb today and noted no fuel was being injected into the barrels from the accelerator pump. You've mentioned a dissolved o-ring and a high idle adjustment; both lead me to suggest that maybe the issue is inside the carb. A very popular modification for kit car owners is the fitment of twin Weber DCOE or DCO/SP carburettors; these not only deliver the goods but also look very good. If the engine stumbles when given a sharp blip of the throttle, increase the pump jet size until the hesitation is gone. I would up with 1. The zero bypass does not allow any fuel back into the float bowl from the accelerator pump circuit, instead all of the fuel is shot out of the accelerator pump jet when you hit the throttle. Occasionally, the carburetor's idle jet will become clogged with dirt, which will cause the hesitation or stall. They can also cause erratic running that seems to mimic a mis-adjusted float, but worse. The first time through carb adjustments can be confusing, once you’ve done it, all of the stuff in the manuals makes sense. Preset both Low speed mixture & high speed mixture needles out by 11/4 turns. Last week I added a WMW 16% pulley package, with belt tensioner, belt and plugs. Carburetors come “out of the box” with specific venturi (also called a choke tube) sizes depending on the size carb BODY you have. Start with the screws backed out 1-1/2 turns. Not sure what this will equate to, but I will find out tomorrow when I install the rebuilt carbs and do all the settings. This only happens on acceleration when overtaking etc if you back off the throttle and cruise at 40-50 its ok. >told me to expect carburetor problems with the late 1980s Tercels. That's extremely lean in the cruise mode and can cause hesitation or a stumble as it transitions to power mode. Weber carburetors have been seen as standard equipment on the finest racing and street machinery to come out of Europe for over three decades. Step By Step. I have a single weber conversion kit on my 1981 2. When I first installed a pair of Weber 45 DCOE carburetors in my TR3A, I knew very little about them so I started looking for information. if you are going to pull the head off, classicinlines also has an adapter that will allow you to direct mount a 2bbl. The stumble on small throttle openings was shown very clearly on the screen too. Daytona Carbs is located in Florida. Made a vakuum port under the carb in my adapter, and measure good vakuum when idling. It is a stock engine except for Crane ignition on a 002 dist and a tii exhaust manifold. 70 mm, to give a larger shot of fuel under acceleration. The head was very slightly distorted and has been skimmed and the values machined. This web page covers Weber DCOE carburetor theory of operation and tuning as it applies to the Triumph TR3 and TR4 engine. It’s airy-feeling and fun to drive. Back storyI removed the K-Jet (mechanical fuel injection) from the car because it would have cost me more to repair than I paid for the car. 2bbl weber on offenhauser 4 bbl IM Hey jeepers im new to this forum and figured i would ask a question finally that i really wanted to know the answer to. How do we adjust an engine’s idle speed? In the past, adjusting an engine’s idle speed was easy. Remove file tape from the lower intake manifold flange and the carburetor air horns. Established since 1996, we perform high performance carburetor tuning, and rebuilding on any make or model vehicle. Hesitation on Half Throttle but a couple things can affect weber smoothness in the beyond off-idle and not close to wide-open-throttle areas of driving. Replaces worn and defective accelerator pump diaphragm to eliminate hesitation and stumble during acceleration. HOW TO ADJUST CARB ON 1987 TOYOTA PICKUP. Your AED Carburetor is hand built, test run and double checked for performance right out of the box. Why is the engine bogging under acceleration? I recently managed to get the moped running properly, albeit for only a short time. Everything is fine above 2000 rpm but it is a real dog below 2000 rpm. It also pings slightly, even on gentle acceleration. Signs that the fuel/air ratio is too lean are things like; backfires at high throttle settings, hesitation when the throttle is opened, or the motor actually slowing down the more you open the throttle. Apparently the strange Weber numbering system for the F# is that the number is not the "size", but the order each size was "developed. 32/36 DGV weber help I've recently installed a 32/36 on my stock A12 powered datsun sunny and need a little help with its setup. The difference is that this carbs barrels open together for a smoother acceleration with less hesitation. • Jetting the carbs are a whole ‘nother discussion, and there are complete books written on the subject. Modified for maximum HP! Now available in chrome, non chrome, polished or painted in custom colors. The stumble at the idle/main jet transition is a problem with the pump jets almost everyone leaves these alone. loss of power troubleshooting: bogging down [109,583 views] We've launched an improved GY6 Technical Center for 2014! We're in the process of bringing all of these old articles to the new system. The value clearances have been set very carefully. (I have little experience with working on carbs) Took it off the shelf and tore it down. Re: weber carb questions TK i set the jets to what you suggested. Maybe you've been lucky enough to get a ride in a vintage Ferrari or a Weber-carburetor Cobra; if you have, chances are, it's a ride you never forgot. 5) Always check for clogged carb vent lines. 5-13 range until top end where it richened up to about 12. Here's a little writeup I have done on Webers. The Moss kit is complete in every detail, from blower to carburetor to every nut, bolt and washer needed for installation. Hi Gary, Yes, this is a kit I purchased from Weber Carbs directly. When they both sit for a long period of time I pump the gas a lot to get them both started. The problem never occurred at steady speed. The fulcm pivot point can be adjusted. I had it running really well at one point last summer and it seemed easy to get there so I had no hesitation trying another vent/jet and balance. My questions are:-Would it be easier, more cost effective, and more powerful to get the aftermarket carb or convert it to fuel injectors?. If the engine stumbles when given a sharp blip of the throttle, increase the pump jet size until the hesitation is gone. This assembly delivers an initial shot of fuel in the right amount, and duration, to provide crisp throttle response right off idle. I pull it apart for a good cleaning every spring, and the problem has persisted. I had to jet it up pretty significantly to eliminate the hesitation on acceleration and it did drop the top speed about 10mph. Replace the seals. This paragraph also applies to relatively stock engines with the original carburetor. it’s kinda like it will be trying to go, but just can’t quite. Gasket #1932. 2l hesitant acceleration User Name: i can rev it up with no hesitation and no sputtering out the exhaust - I don't know much about the Weber carb, but if. It can replace Holley, Edelbrock, Carter AFB, and Autolite style carburetors with 5 3/16" x 5 5/8" bolt pattern. Page 1 of 10 - Tuning 3 x 45 DCOE 3 Webers - posted in Engine: Im in the process of tuning my Webers but have a flat spot (bogging down on acceleration ) The carbs have only 2 progression holes as they are old ones. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon. Considering that you see successful race cars with the carbs mounted in every possible way, do whatever works for you. Remove file tape from the lower intake manifold flange and the carburetor air horns. I do know that duals would be better but at this time it is not possible. I installed a 1406 carb on a 327 and a Pertronix distributor / coil at the same time. Typical carb screw specs are (all in inch/lbs) 30-40, 40-50, 45-55 (divide by 12 to get ft/lbs). You have to know what "normal" is to identify if this is the cause, but what you're looking for is two nice strong streams of fuel spraying into the carburetor under the choke plate when you work the throttle by hand. Idle is smooth. DELLORTO 48 DHLA CARBURETORS. This is called a Venturi. When you open the throttles slowly the acceleration pump and jets make no significant contribution. Although it was working ok last night, I just went out to start it and it was idling rough. Footage taken from Holley Carburetor Installation & Tuning DVD. So I figured might as well try it. 25 mains and. tuning the jets and metering rods. 4) When the idle jets are right-on, idle speed is controlled by the idle mixture screw, not the throttle stop adjustment. I have a weber 32/38 installed on my 88 wrangler. Until the ignition stuff arrives, the only thing i can do is check the pick up. I thoroughly cleaned the carbs, sprayed carb cleaner through all jets, tubes, etc. This blog is a long time in the making. Some people think you're supposed to turn the idle mixture screws all the way in, and then back them out 2 1/2 turns. make sure number one piston is at tdc, pull the valve cover and then look at the cam dowel. Weber hesitation between 2800 and 3800 RPM If this is your first visit, be sure to check out the FAQ by clicking the link above. Just keep sifting through the posts here with the search function and find as much info about the 32/36 Weber carb that you can find. some side draft Weber. I've been fiddling with the idle air mix and idle speed screw. I have also balanced the linkage. So I am guessing that this setting is not a critical one for the carbs. I'm going to have a chat with Burlen tomorrow, but I have a feeling that this may be beyond a carb rebuild. • So, why not use air synchronizers?. The Weber wants no more than 3 PSI otherwise it will flood. I have a stupid question. Custom Carburetor Tuning and Rebuilds. The original high performance part for the Samurai is the 32/36 carburetor. Carburetors come “out of the box” with specific venturi (also called a choke tube) sizes depending on the size carb BODY you have. If not, clean the carburetor and work the butterfly with your hand to loosen it up. gday all, ive heard from a few people and numerous posts on the site that putting a webber 34 adm carbie on my 202 blue (currently with Varajet 2 carbie) would be a good move. The mixture screw is at the carb base on the passenger side, pointing diagonally back at the firewall. But surprisingly the jets aren't fare off. And worse, many claims of lean conditions and rich conditions are contradictory. This is called a Venturi. I have a Weber carb on both my Shay & truck. Maybe you've been lucky enough to get a ride in a Ferrari or a Weber carburetor 289 Cobra; if you have, chances are, it's a ride you've never forgotten!. But, at very gentle acceleration from below trnsition point, I experience a slight hesitation. It turned out that the ignition also needed attention. Remove file tape from the lower intake manifold flange and the carburetor air horns. Original blueprints for 200 mpg carburetor found in England. I have a weber 32/38 installed on my 88 wrangler. Corvairs do not have enough acceleration to cause front to rear starvation, and while the brakes might be able to do it, who cares under braking! The second advantage is you can change jets without taking the carb apart. Was curious a good place to start with some off idle stumble when the car gets some heat into it. Vaporizing fuel can also cause the throttle valve of the carburetor to freeze. Carburetor Fuel Mixture (Fixed & adjustable jet carburetors) 1. New Page History and development A carburetor was developed by Enrico Bernardi at the University of Padua in 1882, for his Motrice Pia , the first petrol combustion engine (one cylinder, 1,225 cc) prototyped on 5 August 1882. This Carburetor is for all 1600cc Dual Port Engines. OEM Nikki Carb Repair. Could this be the accelerator pump and if so should I rebuild the carb, or buy an Edelbrock 1409 600 CFM. A Tale of Two Carbs, Part 1 Carter YF Rebuilt, Lessons Learned. Edelbrock Tuning _____ Originally Composed by Don At FBO Systems Edited for clarity by some anonymous poser. For twin Dellorto suggest you try what ever idle holder came with the carby and bump the jet size up or down in increments of 2. Have since rebuilt the Carb, after watching your very helpful videos thank you. That would be great if it was that easy. Check timing again. If that doesn't do it, try just cleaning out all the carb jets, emulsion tubes included. 1964 Lotus 7 (series 2) NOT A REPLICA! This Lotus 7 serial number SB 1428 has been restored to a very high level. Runs great for about a half hour on the free way and then all of a sudden I get a little hesitation. Idle should be adjusted using the bypass screw on the side of the carb, not. 7LX 1996 (total 320 hours), with mounted 4BBL Weber carburettor. Going downhill at around 3K with light throttle it kind of jerks or stumbles also. Most people experiencing hesitation think, "put in bigger jets" right off the bat. So now, there is not enough fuel to burn the air, and the motor stumbles and stalls. I have made the description to introduce principles of the general functioning of Weber carbs. The Weber DGV was originally designed for a 6-cylinder European Ford. Timing, points, rotor, valves, plugs, FP A-OK. The Hako is more like 500cc per cylinder, but I think maybe I already have the big one, since the models for the 1300cc Alfas etc are a different code. It idles fine, but when I put my foot down, the engine bogs down and dies if I dont let up.