Consider engine response, altitude and temperature conditions (from tables above). I have a few questions on the accelerating pump assembly, control rod and its adjustment. Backfiring caused by internal carburetor problems is a result of a defective accelerator pump. If the engine either hesitates or stalls upon acceleration due to the carburetor, the carburetor's accelerator pump nozzle may need to be cleaned or the secondary throttle plates may not be closing all of the way. Both of you sound like the accelleration pump diaphram needs to be replaced. It's been suggested to me that the oil separator and associated hoses might be worth looking at next, as well as checking the DISA valve for play/sealing. This is a safety problem I have experienced first hand with my new SR5 and a rental car, a Hyundai Sonata in a trip through Florida. Actually, it can be a real challenge to get things to carburate right after something as simple as an exhaust pipe change. I stepped on the gas, and there was severe hesitation when accelerating if I kept the gas pedal pressed. Hesitation on acceleration, low power. Bike runs and starts up great BUT I'm getting hesitation when accelerating and found my right cylinder running rich but left is fine. Your jetting and rods are what is stock according to the manual. 2016 Forte 1. 1976,Chevy,Montecarlo,305,rebuilt. New gas tank (old tank had too much rust inside), new fuel lines, fuel filter. 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. 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. In most cases the "hi" fuel screw will not have to be turned more than a one-quarter turn in either direction. Rebuild the carburetor. It's also possible that the car is hesitating when accelerating because the carburetor is failing. Carburetor Adjustment for Chainsaws Carburetor adjustment is critical on chain saws and other two-cycle engines. Dave replaced the Pierburg carburetor with a rebuilt German 427-1 model that he bought from Keith. I bought the saw used a few months ago. The hesitation could almost be classified as a misfire at times but feels more like flooding. I had three ball checks that I replaced but both the Ford manual and the instructions with the kit show a ball check weight on top of the ball check next to the accelerator pump. I decided to leave it overnight and continue, as the rough idle and acceleration hesitation was worse when cold. During acceleration tests, if you noticethat the car first hesitates and then picks up, it’s a. Rough acceleration. Perhaps that's a bit much for my particular KLR. Warm the engine to operating temperature. Pull it apart again. No Diagnostic trouble codes were thrown - per ODB II scanner. 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. bottle that last a long time. My idle was so bad it started dieing on its own. RE: Carb Question - Hesitation upon inital acceleration Most likely the accelerator pump or the adjustment of the accelerator pump. 0L Mercruiser LX 1992 Hesitation. At high speeds the 47 hesitates. When you are at an idle and you floor the throttle it will hesitate for a moment and then continue to rev up. 500 RPM (up-down-up-down) - possible drop of RPM when running WOT, say from 4200 to 3. It would only do this when speed got up near 50 mph or greater. Hard acceleration then to completely. The problem I have is stumbling or hesitation when I hit the accelerator hard or when at low RPM and coming out of a turn. A car sputters when accelerating due to the fact air and fuel is not being properly mixed, therefore, forcing the car to run on unburned fuel. Rough Idle, hesitation on acceleration, loss of power When I start the engine its starts up right away with no issues. Car has a stock 283 CID V8 engine with a Rochester 4-bbl carb. Everything seems to be correct, but the computer will not advance the timing on accelleration, and I get a LOT of hesitation under load. Are you happy with the plug color at different throttle positions,ie;closed,1/4,1/2, and full? Reply by minifig-phil on 05/05/2003 04:47:31 AM. The pump diaphram can be changed in a matter of minutes and on the car, LITERALLY!! It's on the passenger side of the carb, towards the front. I'm sure it's a simple adjustment, just need a little guidance. 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. In my Samurai, the. The kit obviously had extra parts for the different iterations of the carb. The Engine Hesitates When Accelerating. 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. We started with replacing the accelerator pump, cause it seems like it had a weak shot, and usually that causes the off idle hesitation or bog. Cleaning the idle circuit passages requires compressed air. 84 22R Hesitation/Stutter Problem well i geuss if it sounds like a hissing sound when you accelerate. wrong carb for motor or disty. If you ease into it, it’s fine. A car sputters when accelerating due to the fact air and fuel is not being properly mixed, therefore, forcing the car to run on unburned fuel. It doesn't advance until the engine gets to maybe 1200-1500 rpm. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. Rough acceleration. I rebuilt the carb, everything was done correctly but no matter how much adjusting I did, I couldn't get rid of the hesitation after it warmed up---cold with choke on, ran perfectly. Made me think of carbon'ed up plugs and I dismissed it at that. Just completed a top to bottom rebuild on a 1959 "292', and have a big hesitation on accelerating - have a Autolite 2100 , timeing is set at 10 degrees BTDC - starts great and idles good - Acc. I did not notice hesitation on test drive, but immediately noticed on mine. The accelerator pump is supposed to provide additional fuel needed during acceleration. Symptoms include missing, backfiring through the carburetor, reversion (fuel dripping out of the air cleaner) and poor acceleration. carb is single barrel. You can see it when you look down the throat of the carbgoose the throttle and you should see a good shot of fuel deliveredif not it is likely suspectIf the hesitation is after about 900 RPM then look at your metering adjustmentcheck it anyway as the two are related to good acceleration. Or if I am at idle and hit the pedal, there is a hesitation before the engine "kicks in. It doesn't advance until the engine gets to maybe 1200-1500 rpm. I'd be cruising on the highway and step on it and it would cough and sputter and then clear up. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. 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 focus of my research was on the hesitation and backfiring I experienced on acceleration. Since 1938, Edelbrock has manufactured its core products in the USA for quality & performance. The carb's cfm is directly related to your engine's cubic inches and maximum rpm. My explorer is having trouble accelerating, especially from a stop. Hesitation/bog at 3000 rpmno longer able to pass on freeway 3000 rpms it just fumbled and wouldn't continue accelerating. One of the most common symptoms that the accelerator pump is having a problem is rough or sluggish acceleration. Footage taken from Holley Carburetor Installation & Tuning DVD. Dirty Carburetor - Bad fuel may also cause harmful gum or varnish deposits to form inside your carburetor restricting or clogging vital carburetor passages and jets, resulting in uneven fuel supply and poor acceleration. This paragraph also applies to relatively stock engines with the original carburetor. Hesitation during acceleration??? I am having an issue with my 2012 1. Your Handyman Zone is a general informational site on how to improve, repair and otherwise maintain a consumer's house, appliances, garden, vehicles (cars, ATV's, tractors, etc. Car has a stock 283 CID V8 engine with a Rochester 4-bbl carb. So I got a 2003 arctic cat 400 in a trade it was sputtering a little so I drained gas and cleaned the carb. Pay close attention to the small holes in the carburetor jets, just because you can see light through the hole does not mean it's not restricted by residue left from evaporating fuel causing a lean fuel mixture. In my Samurai, the. Carburetor Adjustment for Chainsaws Carburetor adjustment is critical on chain saws and other two-cycle engines. I can drive the car but I have to slowly accelerate from a stop or I risk stalling the motor. A bad distributor advance can cause a hesitation when stepping on the gas, but we aren’t addressing that here. The air element (filter) is clean and the plugs are new as of last year. When stopped fully, accelerating to pull away uses more power than cruising or just driving at constant speeds. All things are good on the motorcycle except when it sits it leaks and that upon acceleration, there is an on again off again hesitation. Is the carburetor new, if not was it rebuilt? A used carburetor that was allowed to have fuel dry out in it will likely have plugged passages. I have a 2002 Shadow VT1100 and am having some acceleration and throttle responsiveness issues that just started this season. The fuel in. Keith replaced the throttle shaft bushings in Dave's Pierburg carburetor, but it didn't help much. This is what gives you stalling, uneven idle, flat spots in acceleration, and total lack of good performance. Hot Starting Problems Having problems starting your vehicle when it is hot and shut. Make sure the battery cables are nice and tight first use a socket or a wrench. Perhaps that's a bit much for my particular KLR. My 55 tbird is having acceleration issues. RE: Carb Question - Hesitation upon inital acceleration Most likely the accelerator pump or the adjustment of the accelerator pump. This happens ofter when pulling up a rolling hill or accelerating briskly from stop. That also be caused by the timing not advancing fully or the power valve in the carb not opening. Some symptoms of bad carb tuning include: loss of power at high throttle (flooding), bogging even when the engine is warm, stalling, running rich or lean (too much or too little oil signified by the fouling or destruction of spark plugs) and bad acceleration. A screwdrivers width turn can make a diference. 2) Ignition timing retarded too far. 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. Easy Fix for Jeep 258 Carter BBD Idle Problem. Carburetor Adjustment for Chainsaws Carburetor adjustment is critical on chain saws and other two-cycle engines. #1: Hesitation at low rpm ??? (solved) Author: vira-go, Posted: Thu Jun 03, 2010 5:47 am I just bought the bike a couple of months ago, 1994 XV750. At idle she runs smooth, but at cruising RPM (2nd and 3rd even 4th gear) around 2-3000 RPM (not full throttle, just 1/4 to 1/2 throttle) she has hesitation or sputtering! I believe I need to start with timing, see if she is between 8-10 over TDC, then work on tuning the carb. Hesitation during acceleration??? I am having an issue with my 2012 1. Could the carb need cleaning? HELP. It has the stock cam with timing set at 0 degrees (stock setting). Experiencing hesitation/misfiring/bogging down sensation under light to moderate acceleration. Poking a small piece of soft copper wire through all the holes, followed by a good blast of air or carb cleaner works well. The bog or hesitation may be caused by a momentary lean condition when the carb goes from the idle throttle postion to the main metering system. 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. It starts very easily and will idle all day long. Joined: Mar 3, 2001. 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 a 20 year old Homelite ST-155 weed eater with a Zama C1U-H41 carb. by Terry L. Ive had a problem with the vent tube before but I have ridden the bike with out the gas cap and it still happened. We had it looked at - They replaced the carb. The circuit also has two basic elements. I have a 99 GTX LTD with two problems: 1) Stalls when accelerating from stop - once you get it going, it's great! Never hesitates or misses a beat at higher RPM (above around 30mph). Constant hesitation is covered under “surging”. Rebuilding or replacing the carburetor may be necessary. 2) Ignition timing retarded too far. Carbs were rebalanced and acceleration above 3000 RPM is smooth as glass. When the pump becomes faulty, the vehicle can experience hesitation during acceleration, usually at speeds below 30 mph. For many years my venerable '67 VW Bus has run perfectly. If I lift on the pedal or if I go harder on the pedal it will recover. The problem we most often see on a engine with a Holley carburetor is a hesitation on quick acceleration, the cure we use for this is to install an accelerator pump upgrade kit part #1330 that we get from Ole�s Auto Parts, the pump upgrade kit makes the accelerator squirt more active. Just do regular cruising, light acceleration etc, don't hot rod it. much more narrow. No excessive valve lifter noise. While accelerating slowly at low speeds between (20-30) is when it occurs. 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. The only way I get it to speed is to nurse the throttle up above 2000 RPM then it takes off fine. I do agree that you may want to check for obstructions in the prop, and drive shaft alignment. I have a 2003 hyundai tiburon 2. Poking a small piece of soft copper wire through all the holes, followed by a good blast of air or carb cleaner works well. If the other carb doesn't improve the problem, I'll try a new coil and hope to hit paydirt. They eventually wear out the carb body where the shaft rotates, however, there is a bushing kit available to fix that. For instance, the engine sounds to be accelerating to higher RPMs, yet feels as if it has no power. 5 turns out and turning in until the hesitation disappeared but that only lasted a week before the hesitation and sputtering came back. Only under a steady state cruise speed, at any speed, the car would seem to hesitate or stumble. Carburetor Tuning the Scientific Way or A new carb will come with instructions, and a phone number to call if you have problems. It would only do this when speed got up near 50 mph or greater. When cold, it typically starts without any issues, but once it warms up it tends to sputter and stall out. The valves are set, carb's in sync, enrichment levers are adjusted the same and floats set the same. I just took out my 79 T/A today, and on the way home, I was at a stop sign. This happens ofter when pulling up a rolling hill or accelerating briskly from stop. 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. When driving along gradually accelerating/keeping a steady speed, it feels very slightly lumpy (only slightly) but, sometimes when you get into 2nd gear and give it some, it really hesitates then goes and hesitates again until you get into 3rd. Ive bought this 79 bronco w/ a 351m all stock. Insufficient burning inside the engine will make the car hesitates or jerks when driving. Just completed a top to bottom rebuild on a 1959 "292', and have a big hesitation on accelerating - have a Autolite 2100 , timeing is set at 10 degrees BTDC - starts great and idles good - Acc. The kit obviously had extra parts for the different iterations of the carb. How much does Engine hesitates during acceleration Inspection cost? Get an estimate instantly. I would check the ignition timing, dwell, and spark output. Most likely the accelerator pump is defective, or the delivery circuit is plugged. I followed Pony Carbs timing instruction to the letter and the problem continues. Only hesitates under load, can rev engine in the shop with no hesitation or stumble. Edelbrock has a carb manual on there website. I have a 2003 hyundai tiburon 2. 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. The most common accelerator pump-related complaint we hear is a hesitation on quick acceleration. Engine Surges. by Terry L. This is the "hesitation" or "bog" that y'all are getting when you suddenly hit the gas. I have a friend who has a 2006 Mazda Tribute 4 cylinder. 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. It was running pretty rough when I first bought it. If the outlet on the rear carb is not warm, it's not getting enough heat. I have a 74 super beetle with a hesitation on exceleration any gear can anyone help - have adj. The carb (or something) has a hesitation or "flat spot" on acceleration from a full stop. Instead of get-up-and-go, you get hurry up and wait. Your definitive guide to Engine hesitates during acceleration Inspection. The fuel system diagnosis for engine hesitates when accelerating warm says: - secondary air valve sticking or binding (4bbl) - vacuum leaks - loose carburetor or manifold, leaky gaskets or disconnected hoses - faulty ignition restricted exhaust - distributor vacuum advance not operating - idle transfer system dirty - idle speed low or incorrect. An air leak can cause carburetor backfiring. This doesn't happen in neutral only when accelerating. hesitation in acceleration, 2003 Mustang GT 4. But only a fast flick of the throttle. and give false information. Dirty carburetor, air filter system leak, intake leak, valve adjustment, low compression to name a few. Mikuni Carb Kit Installation and Tuning Instructions - Updated 3/30/18. FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428) - Motorcraft 2100 carb stumble - My 2100 carb wants to stumble/die just as I leave idle. With the timing set, now you can see if the acceleration hesitation is still present. Hesitation on acceleration, low power. Its a bone stock California-smog bik. 3 hesitation, stumble, lean and random misfire codes, worse when cold. 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. It 's the lean fuel mixture of not enough fuel and too much air caused by a compromised carburetor or some other component that makes your Chevy hesitate. 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. I am trying to tune out a hesitation in the off idle part throttle range. Show Off's. However, a lean condition on acceleration will usually cause backfiring through the carburetor. 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. A carb kit for a 1975 Honda may be harder to find than you think. real lean will be stall out on acceleration and may blow the air cleaner off, and puncture the vacuum booster on the brakes (ask how i know, and took 6 months to have eyebrows :-D ). Do as suggested above, remove the air cleaner (with the car not running so you do not get a backfire in your face) quickly move the trottle from idle to full acceration. When cold, it typically starts without any issues, but once it warms up it tends to sputter and stall out. In all cases, moving the jet further into the carb leans the mixture, while moving the jet further out of the carb richens it. You'd better start searching for that now or maybe even a used carburetor, if you can find one. ) These quality pumps are the answer to today's E10 & E15 pump gasoline. When a carburetor has been lying on its side, the float can catch on the side of the casting. This cured the idle problem on the one carb so it idles perfectly now, same as the other one. Try a larger jet in the carb or raise the needle on the diaphragm. Manually operate the throttle valve or plate while looking inside the air horn of the. When it does do it, if I ease up on the pedal alittle it stops. Define hesitation, Are you taking about a stumble on a normal acceleration from a traffic light?. But from idle speed and up to 3000 rpm, if I keep the same throttle position (wich by the way is minimal throttle), the RPM go up very slowly, and suddenly, after the 3000 they go up like a beast (still keeping the gas at the same position). It idles fine, drives fine. They have a whole suite of adapters for testing all sorts of DIS systems. The accelerator pump provides the extra fuel which is required for rapid acceleration as the throttle is opened. If all of the above is not the root problem that cause your car hesitates when accelerating, you might have to send it to a trusted mechanic and tune the engine. Quarter or part throttle acceleration is fine and acceleration once the engine is up to 3000 rpm's and over is fine; no stumbles. When stopped fully, accelerating to pull away uses more power than cruising or just driving at constant speeds. A backfire (lean condition) on acceleration also calls for a step up in pump nozzle size. BUSHMAN'S CARB TUNING SECRETS. Just cruising is fine and 100% throttle is fine, its just this light acceleration where it hesitates. 050 a/f mixture 2 1/2 turns out. 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. 351m,hesitation - posted in 73-79 Ford Truck: Need some help. acceleration Sputtering and popping was the first indication of trouble with mine (see: Another one not running). Could use more info such as year, make, model, engine and if it has a carburetor or is it fuel injected. The screw on your carb is a pilot,fuel screw. Gday all, what could be causes for a reasonably standard ( has mild cam and extractors ) 2 litre escort to give a slight hesitation when you first accelerate. The pump diaphram can be changed in a matter of minutes and on the car, LITERALLY!! It's on the passenger side of the carb, towards the front. Alert! Please do not buy anything or pay anyone on this forum. much more narrow. When a carburetor is first installed on an engine and the vehicles fuel shut off valve is opened the first time, a carburetor may leak gasoline initially because the float has stuck. Set the timing, made sure everything was lined up like it should be. When starting off in first gear and starting to accelerate the bike loses power/hesitates temporarily like it's not getting fuel for about a second. I have a 1989 Supra Sunsport with the 351w engine and Holley 4 barrel carb (4160 I believe). But first, you do mean the accelerator pump inside the carburetor, right? If the accel pump is working well then you will see 2 very strong streams of fule spray out into the carb bores when the throttle is moved. This is a popular carb for the small block Ford and is the trickiest Performer carb to tune. has anyone been through this? would changing pump cams help? this is 1850-9 carb. I changed the accelerator pump and I am getting a good squirt of gas in carb. I bought the saw used a few months ago. If the issue persists even with a fully warmed up engine then you could try going a bit larger on the throttle pump jet. 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. Changed the distrubutor cap, rotor button, fuel filter and in-tank (holy crap that's hard) fuel pump. I'm thinking of replacing the spark plugs, dist cap/rotor, fuel filter, new air filter element and cleaning out the fuel tank. You can see it when you look down the throat of the carbgoose the throttle and you should see a good shot of fuel deliveredif not it is likely suspectIf the hesitation is after about 900 RPM then look at your metering adjustmentcheck it anyway as the two are related to good acceleration. The most common problem I see with the engine is it's inability to idle. I have an autolite 2100 that I got from Pony Carbs, put it on a 302 V8. Alert! Please do not buy anything or pay anyone on this forum. When I let off the throttle at lets say 35-45mph and try to hit the gas again it does the same thing at the same point in the throttle range. 1976,Chevy,Montecarlo,305,rebuilt. Vacuum checked and at 18 and steady at idle. Hesitation, stalling, stumbling, flatspot, or deadspot during acceleration: Backfiring or spitback through carb. and give false information. The carb (or something) has a hesitation or "flat spot" on acceleration from a full stop. Thanks keebo. An engine that hesitates, stumbles or misfires when accelerating or when it is under load, is an engine that is either sucking too much air, not getting enough fuel, or misfiring. Quote Reply Topic: Hesitation Problem L-134, CJ3A Posted: 24 Sep. My first guess , based on the the symptoms is accelerator pump or what ever does that job on scooters. Engine hesitation, almost by definition, usually goes back to a misfire in one or more of the cylinders. When cold, it typically starts without any issues, but once it warms up it tends to sputter and stall out. Lower the needle one notch and repeat the test. The motor hesitates and sometimes dies out when I push on the gas pedal from a stop. The carb’s cfm is directly related to your engine’s cubic inches and maximum rpm. Re: Weber carb hesitation under load Well, remember too, I'm using Ford distributorless ignition system on my car. you either have to buy that boyseen (sp) quickshot part, which only lessens the hesitation it doesnt completely make it go away, or i think (cant remember for sure) you can change the accelerator jet to again lessen it. The problem I have is stumbling or hesitation when I hit the accelerator hard or when at low RPM and coming out of a turn. Actually, it can be a real challenge to get things to carburate right after something as simple as an exhaust pipe change. This cured the idle problem on the one carb so it idles perfectly now, same as the other one. The carb was completely gone thru and I installed a new carb kit. That way you don't mix up the parts from each carburetor with parts from another. I have always added a small pour of Sea Foam into my gas tank when I fill up to keep the carb and fuel injectors clean. 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. [Diagnosis 1:] Check the health of the knock sensor. 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. #928607 Mon Mar 18 common complaint of a stumble or hesitation when I hit the accelerator pedal. Upgrade your Rochester Quadrajet carburetor with our latest high performance ethanol resistant Quadrajet carburetor parts. When you step on the throttle, the engine seems to bog down and in some cases die. " Your Samurai has or will have a flat spot in carburetor. I purchased the Ethanol Equalizer from Amazon for around $24 for a large 16oz. by Terry L. How to Cure Off-Idle Flat Spot "Glitch" in Honda GL1000. They eventually wear out the carb body where the shaft rotates, however, there is a bushing kit available to fix that. carb, ignition,new on/off switch etc. Vintage Chevrolet Club - Chatter Forums The VCCA is nonprofit organization dedicated to the preservation, restoration and enjoyment of all Chevrolets and GMCs. Taking off from lights it starts bucking/ hesitating / losing power. Eddlebrock 750 carb with mechanical fuel pump. Alert! Please do not buy anything or pay anyone on this forum. You may have to register before you can post: click the register link above to proceed. If I layed off the gas a bit, and did a smooth acceleration, it seemed just fine, but if I got on it, it would really hesitate. When one or more cylinders stops firing, the power cuts, and the vehicle hesitates under acceleration. Other symptoms of an air leak include a slow return to idle or an irregular idle. There were some problems with the engine on the Archer that I fly a lot (club plane). When I ran the bike it still showed the same hesitation on acceleration without choke and popping on deceleration, but now putting the choke on at idle kills the bike, but turning on the choke during acceleration clears the hesitation. Ive bought this 79 bronco w/ a 351m all stock. 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. Manually operate the throttle valve or plate while looking inside the air horn of the. Holley Carb Trouble Shooting. Inside the CV carburetor there are a series of tiny passages connecting the mixture screw, pilot jet, and air intake jet located on the front face of the carburetor (pictured below). The boost and timing is controlled by a MSD 6AL2 controller. 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. The type of carburetor used on most 150cc GY6 type engines is a Keihin style CV carburetor with a 24mm throat. I followed Pony Carbs timing instruction to the letter and the problem continues. Hesitation and surging on Blazer 4. Dandy! I gave some thought to a vacuum leak but they normally cause problems at low speeds, mainly a high idle and hesitation when accelerating. Delay in acceleration happens when the engine does not get enough power. Will accelerate fine when cold, but only for a few minutes or less than a mile until it’s warmed up enough. Jax: "Just got a Solex for my '55 3B and so far the hook up is going O. i finally started to wonder if it could be something going on with the governor. To my knowledge everything is all original including the Holley 4160. New gas tank (old tank had too much rust inside), new fuel lines, fuel filter. 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. The stumble/hesitation at 3000-3500 is still very much present. real lean will be stall out on acceleration and may blow the air cleaner off, and puncture the vacuum booster on the brakes (ask how i know, and took 6 months to have eyebrows :-D ). (The normal method of overcomining any hesitation problem is to run the carburetors rich - replacing the lost vacuum advance with more fuel, so if a carburetor runs a little lean the hesitation reappears). It has always had the hesitation. If the engine either hesitates or stalls upon acceleration due to the carburetor, the carburetor's accelerator pump nozzle may need to be cleaned or the secondary throttle plates may not be closing all of the way. In most cases the "hi" fuel screw will not have to be turned more than a one-quarter turn in either direction. Open mufflers: "Gutted" mufflers with stock (or stock-like) header pipes tend to perform poorly in the same rpm range as straight pipes and exhibit similar symptoms. I’m having a problem with my Javelin cutting out on a hard acceleration from idle. Check the float level and adjust to the. 3) Clean out the nozzle tip. If I hit it hard the car stumbles then takes off. Once the RPMs are up there the saw is fine. My guess is the obvious one: Something did not seal when you worked on your carburetor. Dirty carburetor, air filter system leak, intake leak, valve adjustment, low compression to name a few. This doesn't happen in neutral only when accelerating. This in my experience it the biggest factor when it comes to hesitation on these cars. Hesitation on acceleration, low power. and give false information. Sounds bad and drives just as bad as it sounds. Tonight, I'll put the old carb back on that I know worked in order to try to isolate the problem, ignition or carb. If you ease into it, it’s fine. Steady state at any speed fine. Cure The Bog And Sluggish Response On Your Holley Four-Barrel Carburetor By Properly Adjusting The Accelerator Pump Assembly. Manual transmission, and sometimes feels like bucking by a novice stick-shift driver. I have been completely through the carbs, including new sliders and diaphragms. Often, this is made worse by the wear of the brass shaft bushings that have allowed the shafts to rotate improperly, thus compounding the problem. When driving along gradually accelerating/keeping a steady speed, it feels very slightly lumpy (only slightly) but, sometimes when you get into 2nd gear and give it some, it really hesitates then goes and hesitates again until you get into 3rd.