Define hesitation, Are you taking about a stumble on a normal acceleration from a traffic light?. Holley carbs come with a standard shooter size which differs by carb list#. 2) Reset timing. The usual complaint when the accelerating pump circuit goes bad or becomes defective, is a noticeable "flat spot" when trying to start from a complete standstill or a hesitation on acceleration. Having a problem with the engine. Check the float level and adjust to the. 1977 mgb roadster with a manual choke Weber DGA carburetor. 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. The first step to identifying the cause of this is to find out if the car is fuel-injected or if it has a carburetor. You should also tune your carb after a carburettor rebuild. 81 xs650 BS34's 160 main jet hesitation mid range. let the throttle close and don't touch it until you're finished setting the choke. Edelbrock Sputtering and Bog at WOT Acceleration! I have found that to be the best way to set the mixture and it corrected a lot of hesitation on my carb. Insufficient burning inside the engine will make the car hesitates or jerks when driving. At the very least, you'll be able to give your mechanic a head start and save yourself the extra money it will cost for a diagnosis. The engine cruises down the road very well. The most common accelerator pump-related complaint we hear is a hesitation on quick acceleration. The mighty Harley is slowly loosing its carburetor. I've swapped out the stock garbage carb on my '83 CJ I6 for a Motorcraft 2150 and I'm having some problems tuning it. Eddlebrock 750 carb with mechanical fuel pump. The Engine Hesitates When Accelerating. The first is caused by the progression, or off-idle circuit, giving up before the main venturi starts to supply fuel. Is a carb vehicle with an engine fuel pump. If I bring on the throttle hard, the bike stutters, then accelerates. So I removed the carb and noticed jets were slightly blocked, took them out and cleared them with airline, cleaned the bowl as there was a small amount of grit in it, fitted all back together and fired it up. Classic Inlines offers rebuilt 1100-1V carburetors which are re-calibrated to eliminate the problems commonly found in factory calibrated carburetors, such as hesitation and/or flat spots. lumpy idle and acceleration 34 Answers. Carburetors come “out of the box” with specific venturi (also called a choke tube) sizes depending on the size carb BODY you have. Footage taken from Holley Carburetor Installation & Tuning DVD. #928607 Mon Mar 18 common complaint of a stumble or hesitation when I hit the accelerator pedal. But you can troubleshoot this common problem, maybe even fix it yourself. I place transmission in drive and press gas pedal it will stall out. January 21, 2016 By Randakk 30 Comments. Footage taken from Holley Carburetor Installation & Tuning DVD. How big the main jet need to be depends on the size of the carburetor and how much air is flowing. Eddy carb (1405), Eddy air gap dominator, small chamber heads, 194 intake, big rv cam, 8 1/2 to 1 dished, accel everything. another reason for backfiring through the carb. This doesn't happen in neutral only when accelerating. probably because of the compressor load. Today I would like to focus on the Edelbrock Performer 1406 with electric choke. It would only do this when speed got up near 50 mph or greater. noise in the engine causing the ignition timing to be extermely retarded on acceleration. My 420 did this. I read the very comprehensive manual and made a few changes (accelerator rod and the springs in the jet rods). I haven't noticed a certain speed or RPM's when it "kicks". At the bottom of the page are also the oem procedures for a rebuild which applies to single or dual carbs. It has been doing this for a few months and I don't have the slightest clue as to what's going on. Just put in new plugs,Cap,rotor & wires. Problem: The bike starts and idles fine. I have been told it could. The engine runs great drivin. So, when you crack the throttle, it bogs, doesn't advance and then revs and advances. This 80 second video is not to thumb my nose at all those struggling with a cranky carb. Another possibility is the metering rod springs. RamchargerCentral. Now the high-throttle acceleration is great, but low throttle cruising is awful! The bike accelerates from idle ok, but when I back off to just maintain speed it lurches and hesitates like crazy. I have replaced the diaphragm in the accelerator pump. Classic Inlines offers rebuilt 1100-1V carburetors which are re-calibrated to eliminate the problems commonly found in factory calibrated carburetors, such as hesitation and/or flat spots. Still starts very hard. Cranks on first turn. My guess is the obvious one: Something did not seal when you worked on your carburetor. Check for a smooth acceleration from idle to high speed. The slug of gas from the accel. Turn the low-speed adjustment screw anti-clockwise an eighth of a turn if you experience hesitation accelerating. The #5 was loose on my 90 300TT just like Tim's. cleaned EGR valve it now goes like the proverbial off a shovel,it was bunged up with oily carbon sprayed it with carb cleaner. It starts fine. I read endlessly about CV carb coughs. I get the hesitation acceleration issue on my 4. Bucking and hesitation start when acceleration tapers off and / or I'm accelerating at low RPM through the gears. Yesterday I adjusted the idle mixture screws and it looks a little bit better. This paragraph also applies to relatively stock engines with the original carburetor. The hesitation could be momentary flooding. I like to take a tray, one for each carburetor, number the trays, and then put the parts from each carburetor in it's own tray. I recently picked up an 04 CRF100F. Sounds like it's running a tad rich, as evidenced by the backfire. Hesitation usually means a lean condition. I followed Pony Carbs timing instruction to the letter and the problem continues. I installed a rebuild kit on this Weber DGV carb two years ago and got a professional recommendation on which jets to. Basically there are 4 combinations of fuel delivery circuits and all must be tuned separately. 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. The carb I am using is a NOS Holley 9834-1 Here is what happens: Car starts fine hot or cold. I need to get a carb kit and just haven't gotten around to it. (I had others but I will save that for later. I have even started it up and let it run/idle for 10-15 minutes, then Drove off and the Hesitation starts. Insufficient burning inside the engine will make the car hesitates or jerks when driving. problems are basically a hesitation and flat spot on light acceleration and a big bog on hard acceleration. It takes a moment for the vaccum signals within the carb to "normalize" and draw fuel up through the main-jet and jet-needle circuits as they normally would. It needs more power than driving at a constant speed when pulling away from a stop. It takes a moment for the vaccum signals within the carb to "normalize" and draw fuel up through the main-jet and jet-needle circuits as they normally would. we did spray carb and choke cleaner in it yesterday but did not seem to help. Samurais may exhibit a hesitation/flat spot, in any gear, when in acceleration from partial to open throttle. Has a slip on, uni filter, stock air box. Also, the bowls are still full, so I don't think fuel supply is a problem. hesitation during light throttle acceleration750 holley. ) but could detect no change in engine note. When snapping the throttle to wide open the carb hesitates and bogs. When you feel ridges, you know you need to. If I apply slight acceleration from a dead stop, the hesitation / stumble is there, but if more pedal is applied, slides right through the hesitation area. Slight acceleration hesitation driving me mad I was told to start with the timing and make sure that is correct before moving on to carb or anything else. But you can troubleshoot this common problem, maybe even fix it yourself. okay so I'm leaving work yesterday, running an errand before going home on the hottest day of the year so far(100+f). Bucking and hesitation start when acceleration tapers off and / or I'm accelerating at low RPM through the gears. Car has a stock 283 CID V8 engine with a Rochester 4-bbl carb. At start off, even after the engine is warmed up, there is a split-second hesitation when the gas pedal is depressed before it accelerates. depends on a functioning manifold preheat system if the carb is set up in the stock manner. Does anybody have any insight on what this may be? I have been searching the web all day and cannot really find a person whos car had all the same symptoms as mine. Today I would like to focus on the Edelbrock Performer 1406 with electric choke. There is no check engine light on and the car seems to run fine otherwise. You may have to register before you can post: click the register link above to proceed. Hot Starting Problems Having problems starting your vehicle when it is hot and shut. Smooth acceleration requires a momentary increase in the supply of fuel. Proper carburetor setup and adjustment is essential for peak performance and longer engine life. I do know my secondaries are opening but like stated there is a hesitation. The carb is a Holley 750. I've adjusted timing and tuned the carb best I know how but it still stumbles at first upon acceleration and I can't seem to get it running right. 1984 Chry 2. The most common accelerator pump-related complaint we hear is a hesitation on quick acceleration. Loading Unsubscribe from HolleyPerformance?. This started about a year ago and hasn't done it every time we drive it, but lately it's getting worse. These instructions are primarily for the dual carb kits as used on Volvo 544, 1800, 122, and 140, MGB's, TR4's, etc. Jump to Latest Follow 1 - 8 of 8 Posts. Have you ever experienced car hesitation when accelerating? A car hesitates when accelerating is a symptom that shows an imperfect internal combustion in your engine. Rarely do you need a 50cc pump on both the front and the rear of a 850 cfm style carb unless, as was mentioned, the car is a very heavy vehicle. The card idles great and runs good at higher RPMs. We currently have a fairly large inventory of 1V carbs in stock, which are rebuilt and ready to ship, however we're always looking for more cores. When snapping the throttle to wide open the carb hesitates and bogs. The only trouble code it reads is 2-3-1. It would only do this when speed got up near 50 mph or greater. How much does Engine hesitates during acceleration Inspection cost? Get an estimate instantly. This is the single most critical setting on a Walbro carb!. Help!My 1973 240Z with Round Top SUs is bogging out and sometimes stalling on acceleration with low engine RPMs. This 80 second video is not to thumb my nose at all those struggling with a cranky carb. When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. Most orders ship within 1 business day. clifford performance: 47-4520 cast aluminum, single plane, intake manifold 1991-up 4. The motor does not respond and hesitates and may even die. Ive had a problem with the vent tube before but I have ridden the bike with out the gas cap and it still happened. It is a new carb, send back to carb manufacturer and received it back and still same problem, I have all vacuum lines plugged except timing advance and PCV line, all emission controls are removed. New Taotao ATM50-A1 Bogs Down Under Throttle. The only good way to adjust the carbs is to take the craft to the water, but before you do that though, you need to know the basics of a Mikuni carb and what makes them tick. Points just replaced on DVDA. Dirty carburetor, air filter system leak, intake leak, valve adjustment, low compression to name a few. It only does the hesitation sometimes and when the engin Engine Surging and Hesitation While Accelerating - 1990 Buick Regal. Everythig was adjusted and the timing set at 10 degrees. Possibly dirt or gum in one or more carbs. It was the best $17 I have recently spent, and if you are having similar weak/lack of acceleration or hesitation issues, i would say TRY IT for less than $20. Delay in acceleration happens when the engine does not get enough power. Things that have been done: Dizzy rebuilt last year by advanced distributor. My guess is the obvious one: Something did not seal when you worked on your carburetor. They get full of crud etc. Keep in mind, over time and mileage, throttle shaft bushings can wear, allowing unwanted air into the carburetor. What to do?. Lower the needle one notch and repeat the test. It is an inexpensive part that listens to the engine, senses knock and automatically retards the timing. 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. When accelerating or under light load, the engine stumbles, sort of like its not getting enough gas. Under acceleration it has some hesitation and it feels like a bit lack on the power too. its an inherint feature of the stock carb, so if you want to get rid of. isnt a 01 still under warranty? or are you hearing the 'we cant duplicate the problem " line from saturn? my first thought would be to do a throttle body cleaning and see if that affects it, this is very easy, take off the air intake tubes running from the air filter box to the throttle body, get a can of carb cleaner, shoot all inside the throttle body opening and closing it by hand with the. Edelbrock has a carb manual on there website. Please also do not go to any links posted on here. Because of a rich condition at high speed, which caused a smog failure, the carb was recently rebuilt. The throttle response while driving is noticeably better. 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 need help from veteran Subaru mechanics. The #5 was loose on my 90 300TT just like Tim's. How big the main jet need to be depends on the size of the carburetor and how much air is flowing. Decided to go for a Street Demon 625 with phenolic body, as the car is quite original. Unfortunately, I'm having one problem. If the carb is clean and fuel delivery is not a problem, getting the carb to feed fuel at a decent idle speed of between 800 and 900rpm is a simple case of tuning. clifford performance: 47-4520 cast aluminum, single plane, intake manifold 1991-up 4. Define hesitation, Are you taking about a stumble on a normal acceleration from a traffic light?. To resolve a recent stalling problem at deceleration and low rpm <2000rpm, I did the following: - changed fuel filter - cleaned carbon out of throttle body with carb cleaner (was O2 sensor safe), and there was alot of carbon. " So this little part basically, eliminates the flat spot in carbureted Samurais which results in a loss of power. What can I do to diagnose and fix the problem? - Answered by a verified Motorcycle Mechanic. 3) Accelerator pump nozzle has dirt in it. When you are at an idle and you floor the throttle it will hesitate for a moment and then continue to rev up. By routing the fuel line around the front of the carburetor, the fuel to the left of the foremost point is pushed toward the carburetor, not toward the tank. This car runs good at steady throttle but on accel it leans out to the point that at 2/3 throttle it will not accelerate. My Profile My Preferences My Mates. A failing or dirty fuel injector can cause a regular misfire (and a trouble code), which can eventually escalate to stumbling and hesitation. hesitation during light throttle acceleration750 holley Post by rewguy » Thu Apr 14, 2016 12:52 am just as i roll on the throttle gently (off stoplight street driving) the carb has a small rough chug that it works its way through but it disappears by 3000 rpm. Rebuild the carburetor. Accelerator pump is damaged or passageways in the carb are plugged and need cleaning. The hesitation is gone but it is still backfiring through the intake. Hey Mark, I was wondering if you could refersh my memory on the changes in jetting needed vs the alcohol content on the summer vs winter blends. Took it in for other under car issues - they replaced the carb again. Mike, by reading other threads, you really know your carbs. There is no check engine light on and the car seems to run fine otherwise. Also, it accelerates, but not like it should - it seems to take a little bit for it to really kick-in and it feels like during the first 2-3 seconds of doing so, the engine is like loose, missing or something. I have to feather the throttle, and then the engine takes off and accelerates strongly. Carburetor Hesitation Problems With most carburetors, hesitation problems during acceleration are caused by idle mixture problems. One of the most common problems that customers complain about is the spit-cough-pop from the carburetor as a Harley goes from idle to ¼ throttle. Kawasaki Jet skis are know to have issues with their round body carbs. Flow test carb to check jetting. 1977 mgb roadster with a manual choke Weber DGA carburetor. Now the high-throttle acceleration is great, but low throttle cruising is awful! The bike accelerates from idle ok, but when I back off to just maintain speed it lurches and hesitates like crazy. The simple in design little Stromberg NA-S3 carburetor is difficult to make operate properly because it is so poorly understood. has anyone been through this? would changing pump cams help? this is 1850-9 carb. High speed driving just fine. It is better to understand the causes of engine hesitation, so you can fix them right away. - lend me your ear it may be accelerator pump on the carb is getting weak and ready to quit, clogged jet, aforementioned pick-up screen. Again, the primary purpose of this blog is to teach people about their SUs and to show the types of problems that are often encountered during a rebuild so that others can benefit from my experiences. I have leaned out the idle mixture screws as far as they will go without killing the engine, and it still bogs. 2008 at 1:43pm I rebuilt the W-O carb w/master kit from Carter, to include setting metering rod with a gauge I bought from a guy on the G503 site, I set the pump to travel to 17/64", made the start up air screw adj. Starts up and idles fine, but will not rev without hesitation and misfires. Disconnect the fuel feed hose at the rear carburetor, place it in a vessel, and switch on the ignition switch to check for fuel flow. if i accelerate quite slowly it doesnt do it, but that makes driving in traffic a real pain. I installed a rebuild kit on this Weber DGV carb two years ago and got a professional recommendation on which jets to. This paragraph applies to an instantaneous bog, hesitation, or stumble upon acceleration. This carburetor virtually eliminated the stumbling-on-acceleration problem except for a slight "blip" on sharp acceleration. Hey guys, Need your help/advice on some hesitation Im getting with the X. Ive had a problem with the vent tube before but I have ridden the bike with out the gas cap and it still happened. from a dead stop, when I step on the gas, i hear air intake, and then the rpms go down and then up and then the truck responds a second or so late. Below are the top 5 causes of engine hesitation while idle, when cold, or under a heavy load:. 1 Color Line it has a " TU1/K" engine with a single Solex carburetor ( Solex 32 PBISA 12 ) the car was purchased new in italy in 1991 but it was actually imported from france by the dealer. The hesitation could be momentary flooding. Looked at diapham, etc. Find Edelbrock Accelerator Pump Assemblies 1470 and get Free Shipping on Orders Over $99 at Summit Racing! When doing a rebuild on your Edelbrock carburetor, don't forget to replace your accelerator pump with one of these top quality replacement pump assemblies. Engine hesitation, almost by definition, usually goes back to a misfire in one or more of the cylinders. Symptom: When punching the accelerator (heavy acceleration) going up hill or accelerating rapidly when already at city driving speeds or greater the engine begins to pop (upstream exhaust backfire). It almost feels like a badly adjusted carb (from back in the bad old pre-ketchup days). It had a dead spot when i would accelerate and it would not stay running at a intersection and would not idle in the morn. This article is an overview of how to remove and rebuild a carburetor. Lots of folks lately with Holley issues. The only good way to adjust the carbs is to take the craft to the water, but before you do that though, you need to know the basics of a Mikuni carb and what makes them tick. 1977 MGB with a Weber 32/36 DGV carburetor with a manual choke and a 25D distributor. It ran fine but someone left the gas cap off and it rusted, pulling rust into the old Holley 600. Here's one cleaning method to consider:. I just took out my 79 T/A today, and on the way home, I was at a stop sign. That way you don't mix up the parts from each carburetor with parts from another. After two years of fighting with my '73 Cb750 I've finally solved nearly all of my problems with one very simple, very cheap part. Helpful Information. Im running out of ideas i recently bought a gm crate engine for my 76 blazer ive replaced just about everything on the motor when i bought it (new carb, fuel pump, fuel filter, water pump, alternator, power steering pump, plugs wires cap and rotor) the only things i kept were the intake, distributor, and exhaust manifolds. Second City Scooters is were I got the Cabo 150 from for about $2400. If your tractor stumbles or hesitates when accelerating, has a rough idle, floods or idles too fast, you might want to rebuild it using a carb kit. I tried swapping all 3 of the springs and nothing made a difference. I like to take the top off the carburetor(s) and look at the slide and jet needle first. 1952 8n hesitates on acceleration discussion in the Ford 9N, 2N, 8N forum at Yesterday's Tractors. Set your Fuel Mixtures if they need it. It is a new carb, send back to carb manufacturer and received it back and still same problem, I have all vacuum lines plugged except timing advance and PCV line, all emission controls are removed. If there is no gasoline in the bowl, the pump will not work; and this would give a false result. " Your Samurai has or will have a flat spot in carburetor. I'm not sure if any carb rejetting has been done, I have gotten all the documents yet. Any ideas? Oh yea, stock 454, 650 holley carb. Because of a rich condition at high speed, which caused a smog failure, the carb was recently rebuilt. Engine ran fine for 2 years and then noticed hesitation upon hard acceleration and when turning hard to the rightnot to the left. Hesitates really bad taking off from stop lights or just cruising around 2000 to 2500 rpm. With the secondaries held shut, it is less of a bog now and more of a hesitation. 5 V6, 120K miles, well maintained. In other words, the engine should not be missing or have any hesitation. Using the carb adjustment method you used is a good place to start, but depending on the carb you may need to adjust it differently. Loading Unsubscribe from HolleyPerformance?. This prevent hesitation during acceleration. This is a list of common problems that occur with auto's using carburetors. Hesitation under acceleration on 1988 mustang 5. I know this is a cheapo machine but it was free, has been used very little, and other than the carb problem works great. Service, parts, cost & recommendations from YourMechanic. Eventually will start and idles fine once it does. • To prevent spams, you must not use the words "http" ". Open the throttle and it bogs/dies. Possibly dirt or gum in one or more carbs. When accelerating or under light load, the engine stumbles, sort of like its not getting enough gas. Hi, I am trying to fix the problem of my 81' 720 Z22 hesitating when the secondary opens on the carb. You may have to register before you can post: click the register link above to proceed. A bad distributor advance can cause a hesitation when stepping on the gas, but we aren’t addressing that here. The fuel pressure must stay above 5 psi at wide-open throttle; if not, the carburetor will starve for fuel. This problem is very annoying because you look like an idiot when you accelerate hard and the motor almost seems as if it will stall, but if you accelerate at a steady pace, it's fine. 2) Ignition timing retarded too far. However, it has a bad hesitation on acceleration regardless of the gear. A damaged carburetor is responsible for poor performance of the car as well. Ever since I installed the triple carbs this spring, I have been having an issue while accelerating and only while accelerating. If the engine won't start and the tank is full of fresh fuel, test the carburetor by removing the air filter and pouring about a teaspoon of fuel into the carburetor. Still starts very hard. Look down inside throat of the carburetor. It doesn't advance until the engine gets to maybe 1200-1500 rpm. The hesitation is gone but it is still backfiring through the intake. We tailor to all years of Cummins diesels and Mopar related Trucks, Jeeps and SUVs, and with the vast tech and help knowledge of our great members, you can get help or info on practically any make or model vehicle!. I have a 2012, 6200 miles. depends on a functioning manifold preheat system if the carb is set up in the stock manner. The engine runs great drivin. Rebuilding or replacing the carburetor may be necessary. Idle speed now too fast as expected. Tuning your Harley Davidson carburetor is simpler than most think and can be performed with a few common tools. i haven't tested the winter blends yet, but i know the summer blend i had was 83% when you were at the Union race. It acts like the fuel filter is clogged but this model has no fuel filter. It starts fine. Many small cures leading to an overall healthy condition. The kit obviously had extra parts for the different iterations of the carb. I've fiddled and fiddled with the accelerator pump (installed new parts adjusted and adjusted) and it still does it. I am trying to tune out a hesitation in the off idle part throttle range. The accelerator pump provides a single shot of fuel directly into the venturi, through a dedicated circuit and discharge nozzle, or “squirter,” each time the accelerator is pressed. Idle, 0-1/4 throttle, 1/4 to 3/4 throttle and 3/4 to Full throttle. This hesitation is most often caused by the changes in the gasoline’s volatility and changes in carburetor manufacturing. Bike runs and starts up great BUT I'm getting hesitation when accelerating and found my right cylinder running rich but left is fine. You'd better start searching for that now or maybe even a used carburetor, if you can find one. Starts up and idles fine, but will not rev without hesitation and misfires. Symptoms:Hard start, hesitation, slow acceleration, or stalling when accelerating. A properly jetted carburetor, that worked well a couple of years ago, may have lost some of its performance due to today's leaner fuels. It had a dead spot when i would accelerate and it would not stay running at a intersection and would not idle in the morn. depends on a functioning manifold preheat system if the carb is set up in the stock manner. The hesitation in shifting at low speeds when accelerating after slowing down to turn a corner occurs intermittently but is quite noticeable. But you can troubleshoot this common problem, maybe even fix it yourself. Loading Unsubscribe from HolleyPerformance?. The Top 5 Causes. The numbers on it are 9605s. Backfiring during acceleration can also be caused by internal carburetor problems, low compression, leaks in the fuel tank, lean engine conditions, and weak or broken valve springs. The misfire is causing the hesitation; you just need to find out what's causing the misfire. I'm borderline too small on the carb, I feel. We currently have a fairly large inventory of 1V carbs in stock, which are rebuilt and ready to ship, however we're always looking for more cores. What can I do to diagnose and fix the problem? - Answered by a verified Motorcycle Mechanic. if its just the hesitation, ive read this over and over and over that there is little you can do really. I have a stock ford 351w and confused why this wouldnt be enough. Every model is slightly different, but the basic principles apply to all. It runs good in idle and you can rev it good, but when you drive (put engine under load, load being the truck alone) it bogs under initial acceleration and you have to barely accelerate to get it going, but it will. If you attempt to accelerate too hard off idle, to the point where the secondaries kick in, the car bogs and stumbles to the point where it dies unless you lift your foot off the pedal. rawdog · It appears the carb adjustments have little effect. When you step on the throttle, the engine seems to bog down and in some cases die. Basically there are 4 combinations of fuel delivery circuits and all must be tuned separately. Edelbrock has a carb manual on there website. Disconnect the fuel feed hose at the rear carburetor, place it in a vessel, and switch on the ignition switch to check for fuel flow. Been sitting 2 years. The '07 250X CA carb is different than the 49-state model (as in past years), and there is a new designation for the 49-state model that specifies it's for the Canadian model 250X also. The (hesitation) is not as noticable. The proper method of setting the “Idle Mixture Control Screw” in a NA-S3 Stromberg carburetor. I rebuilt my Autolite 1100 over the weekend. Heres my problem: If i accelerate my car from a dead stop the car hesitates upon acceleration from idle to say 10% acceleration, then it bucks forward. Car has a stock 283 CID V8 engine with a Rochester 4-bbl carb. Scooter started normal, but still would not take acceleration without bogging. But the BIG. Mapped by Enginetuner(Plymouth). Hesitation or Stumble When Accelerating. I struggled for years as well. First, make sure that the air coming into the carburetor is clean and free of debris by inspecting the air filter. This can occur on any model, any carburetor, but seems to happen most often with the stock CV Keihin carburetors used on the newer (90 up) Big Twins and Sportster models. Because of that, I'd recommend the following: 1. Hesitation is when your engine misfires, stumbles or lacks power when you accelerate or step on the throttle. I just got a reman. Just cruising is fine and 100% throttle is fine, its just this light acceleration where it hesitates. There is an annoying lag in the engine response. The fuel within the metering passages will lag momentarily in its response to the pressure difference created by this increased air flow. It is stock all the way around, except maybe some parts in the carb. A carb kit for a 1975 Honda may be harder to find than you think. Here's what worked for me, on the cheap (which is my religion). This car runs good at steady throttle but on accel it leans out to the point that at 2/3 throttle it will not accelerate. Hesitation or Stumble When Accelerating. [Symptom:] Hesitation on acceleration, bogging. But the BIG. Re: Weber carb hesitation under load Well, remember too, I'm using Ford distributorless ignition system on my car. When accelerating up a hill or sometimes from a slow cruise the engine hesitates, I get some backfiring and then it "catches" and takes off. Like a dirty air filter, an improper carburetor also causes car jerking as it disturbs the fuel-air mixture balance.