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Su carb choke sticking

su carb choke sticking It may seem odd that one hole in each choke arm is grossly oversize, but it is real and original. At 01:02 PM 9/29/03 -0400, Steve Merical wrote: >"I've been preparing my MGA for winter driving. You might spray some lube into the cable housing as well and work the cable back and forth while you have it disconnected from the carb. The first time it did this it wouldnt start and the plugs were soaked. You will experience a huge increase of power, mileage, and less breakdowns! SU Jets & Tuning While doing a fairly major tune-up on my 120 OTS I again encountered the irritant of having the (SU) carb jets stick in a raised position after I have loosened the adjusting screw and am trying to richen the mixture. The parts are the longer throttle spindle nut, the concentric spring, and the extended choke lever bolt. in which case look for perished pipes ariound the carb, or internally . The choke on both carburetors should be closed. For that problem, replace the rubber grommets. 1 - 7 of 7 Posts Remove the choke cable so you can work the nozzle rapidly by hand Many customers complain about cold starting challenges with their British car. A suction disc (2) is integral with the piston and works in a concentric chamber bolted to the top of the body casting. Option 2 - do I adjust the rods so that they partly operate the jet levers of the other 2 carbs so that continued choke opening then moves ALL the fast idle levers at the same time? Gut feel says option 1 is correct and there is nothing i can do about 1 carb increasing the throttle before the others Sonya, stick with the SU's. read instruction. Island Automotion specializes in the restoration of SU and Stromberg carbuetors. We also made good use of some Evapo-rust. E. A quick way I'm using to ensure my choke jet extends back to position, instead of getting stuck partially down despite pushing the choke lever back in. Check with us for other applications where this upgrade can be used. The HIF, overleaf, differs in some ways. The choke blade should pop open approx. Maybe disconnect the choke cable & operate the choke manually to see if the bike starts/runs OK. All you are really doing during a rebuild is cleaning the carb and all the little passages, and replacing the jets and float bowl gasket. My right carb's choke plate had a busted spring. This is more often the butterfly bushes than needle wear. So when tearing apart the engines I decided to pull the carbs off and remove the choke from the carbs. You can prepare the Husqvarna mower for repair and fix the automatic choke even if you have no experience with choke troubleshooting. However only time my engine changes is when i slide my choke ALL the way over, doing it half way seems to change nothing. . SU Carburetors is the web presence of Island Automotion Ltd. The bad news is that I've got the SU on the car and it starts fine with the choke but dies if you push it in all the way, even when warm. set choke to closed setting,release throttle, tighten ret ring. The choke spring should then close the choke. 2. , sticking bob weights or weak or broken springs. The venerable carburetor is arguably the most recognizable hot rod part. SU Carburetors. Rebuilt to factory new condition with all metal parts replated in Cad yellow finish. It has only one jet (except in a few special types) and very few moving parts. It's not roadworthy at the mo so I can't take it for a proper drive to check the plug colour. 060 alcohol - includes carb, intake, air filter, fuel filter, and fuel pump. As with other parts, put the screws in a bag with a card description. Choke cam - slightly opens throttle butterfly so not to starve engine of air when choke is used (not shown) 20. Carburetter Company Limited also manufactured dual-choke updraught carburettors for aero-engines such as the Rolls-Royce Merlin and Rolls-Royce Griffon. One that will cause hard starts. Triumph Spitfire SU Carbs and Crank Case Ventilation: The original Zenith Stromberg carburetor set up did not have a PCV valve. Start by reassembling the mixture jet assembly: add the washer and spring back, and screw on the mixture screw. In my experience this is true and it starts fine and runs fine on choke. Frees Sticking Manual or Automatic Chokes Dissolves Harmful Fuel System Deposits Eliminates Hard Starts, Rough Idling, and Stalling. Have you balanced the carbs to each other at idle. I will also be listing sets of SU & Zenith Stromberg Rebuilt, Restored & bench Tested carbs & also complete carb, linkage & intake manifold setups. Carburetor: Dog Bone Linkage Alternative. 538 likes · 3 talking about this. You can disassemble and try to clean the carburetor, but it will most likely need to be replaced, as Onan does not make rebuild kits for these carbs. It is very reliable, but it can become dirty and choked — and some parts wear out. The automatic choke is usually a SU Carburetors. I was wondering if maybe my choke plunger is stuck causing my idle to mess up. So, as expected I cant easily start my bike on a cold morning or any morning. Another general method for setting the Choke is to use the three “Pips” (see the photo). If the choke doesn't close on a cold engine, that is a problem. The choke stuck up on my the first ride of the day. Almost all other carbs are fixed venturi carburetors requiring extra bells and whistles—choke valves, idle and acceleration pumps, ad infinitum—and all of which produce a variable vacuum across the throat of the carb. Island Automotion specializes in the restoration of SU and Stromberg carbuetors. There is a meme floating around that shows the best automotive anti-theft device for the modern age – the photo is of the shift lever of a manual transmission car. 521 likes · 1 talking about this. if cleaning choke dont help. If you see that the Plate is too loose or too tight, repeat the process. be/iufojfCjl10 SU carb sticking. When you lift the piston inside the carb up just a tiny bit and let go, it should drop down with a noticeable click or thump. Also if the relay itself is Ok. The choke housing itself can be laid on the newspaper. If there is no pin, take off the air filter and lift the piston 1/32 in. Island Automotion specializes in the restoration of SU and Stromberg carbuetors. . Make sure your ignition timing and valve adjustment is correct, take off the air filters, let the car idle, at idle push the little tab under the carb bodies up (if these carbs have it, if not use a stick or small screwdriver) it should rise the dome piston about 6 millimeter, one carb at time, let us know what happens, will it continue idling with almost no changes, will it stall or will it idle but very rough, you have to do it with each carb and let the engine rev in between the test. When I fire it back up at the next yard it gets stuck In choke mode. The car has dual carbs and the front carb works well. Choke cable (not shown) 18. Remove the choke housing cover and do the baggie trick again. 00. Size is always coded as follows: 1" + [number] / 8" = size in inches. It was a common problem that those coil bimetallic chokes springs in the plastic housing carb mounted and the manifold mounted choke stoves. The individual butterfly's are not adjusted to be matched at idle. Cannot get it to - Answered by a verified Auto Mechanic Regarding the spring loaded needle assembly, I have worked for many years on Volvo carbs both SU and Stromberg. Nozzle not properly centered. e. I tried to push it down as I rode but it seemed stuck. On my Ford F250 truck with a 360 engine, I have a Motorcraft 2100-D carburetor, but it is similar to other Ford engines and other carb variations like the Ford 2100 or Autolite 2100. by driveit Thu Jun 12, 2014 11:38 pm New engine runs great and the power difference is unbelievable, but there is an issue with the carb. Spray some carburetor cleaner on the choke and then wipe it down with a rag to clean out dirt. Failure to do either condemns the choke pull off. You may have a dizzy problem over advancing the timinge. About a month ago I started having problems with the throttle sticking and it's getting progressively worse. Start the vehicle. Choke sticking: If the choke linkage is sticking the nozzle can stay down when the choke is off. . D) AUH 300 Range; AUH 300 Range - Carburetter Automatic Enrichment Device (A. HS: View from the RHS of the car leaning over the engine. The oversize hole allows some "lost motion" so the fast idle can be actuated before choke begins to come on. It is safe for the cleaner to go inside the engine so don’t worry about wiping every last bit of cleaner. Please subscribe an I've been running a Summit carburetor on my 351 Cleveland for about a year. The part you folks are saying that's "sticking". As the piston drops onto the bridge, there should be quiet a metallic `thunk’. Size Matters: Identifying SU Carbs SU carbs come in several styles and sizes. choke cable trunnion ach9042 nipple & 53k3503 screw Complete with screw the choke trunnion is used on nearly all SU carb linkages. Broke off one side but was able to get it out. Turns out both carb domes were slightly misaligned causing the needle to rub and stick. This post describes what the problems were with the front carburetor and what I did to fix them. - 1990 Mercedes-Benz 190. unfortunately. It drops within time and has the distinct ker-plunk sound. Squirt some choke cleaner in the locking screw hole and leave for about 30 seconds followed by an aerosol penetrating oil. The focus is better at the end. Otherwise it may be bad spark, low compression, or a sticking valve. then start up the next day, if the problem is still there gently tap on side of carb with a long shanked screwdriver. I was amazed! When I removed the choke it was full of water and dirt, which when cold freezes up and makes your choke stick! It was a bitch getting the choke out of the carb, I would guess because of the dirt. You should have a small gap between the top of the choke blade and the airhorn. The Numbers. Each carb is identified by one or more letters and numbers. 600 Carb Choke Sticking - Help! - posted in Sledding - General Discussion: I have a 2013 Summit with the 600 Carb twin and love the engine, with one exception. When both carburetters have been dealt with, remove the feeler. If it has a thin metal gasket or little mantle-clock-shaped tabs, put them in the same bag. Hold it down and tighten the locking nut. 88 $ 33 . Carb & Choke Cleaner quantity. Slacken of the choke cable at the carb and remove the little choke clamping screw and pull choke cable from carb end only. 71) which is provided with four calibrated holes and an elongated opening as well as a channelled disc (4) mounted on a spindle which is op erated by the choke control. You will need SU manuals and/or tuning guides. Damper oil temperature fine-tunes control of this. If the choke is free to move but does not close, then it sounds like your choke heater spring is buggered up. (1 mm) with a thin screwdriver. Auxiliary Enrichment (Thermo) Carburetter ; Automatic Enrichment Device (A. Clean. D) AUH 300 Range; AUH 300 Range - Carburetter Automatic Enrichment Device (A. D) AUH 300 Range; AUH 300 Range - Carburetter Automatic Enrichment Device (A. Check for a sticking choke, clogged air cleaner, or a Ya, worst you can do is a new carb. Hello all, New to the forum here. Choke return spring - ensures jet remains in the normal running position – choke is inactivate when engine is warm (not shown). i'll pull the carb and check it out in more detail tonight, maybe the previous owner overtightened the 4 mountng bolts and warped the housing? it says that is possible in the instructions. Step 7: Run the engine until it warms up. Repair or replace. One possibility is the choke on front carb might have been stuck because it drove great for several miles before it puttered Sonya, stick with the SU's. If a triple carb has been sitting for a while and the "choke" (enrichener) has not been operated for a while, chances are you may be looking at a brass "plunger" that is now stuck in its little "hole" in the carb. The choke linkage is towards the top of the picture (with return spring) and the throttle at the bottom. There is ported vacuum provided on the front carburetor for vacuum advance distributers than need a ported source. On the carb, the choke operating link was bent to shit because it looks like whomever installed this plate tried to compensate for the new carb height by working that link, instead of the divorced choke mixture adjustment. I have a few SU carbs under various old bonnets. They should be removed from the engine for cleaning. SU website. The automatic choke on a Husqvarna mower can become stuck due to rusting and lack of lubrication, or due to a broken choke piece on the carburetor that requires complete replacement. Sonya, stick with the SU's. some-times externally plumbed. Disconnect fuel line at tank and blow out with air hose, reconnect line and check again for fuel discharge. Adjust choke to set a 2300 rpm fast idle for 20-30 secs, then either turn down the choke to set a Gas pouring into the crankcase is not a choke problem, it is a sticking or worn needle in the carburetor. It also puffs out Everyone, I'm the one trying to figure out why my newly acquired 1971 MGB died on its way to its new home. It also effectively cleans all nonpainted metal parts and surfaces. You pull on the cable and the cable unhooks itself from the choke plunger, leaving the choke plunger seized and stuck down in the carb (possible). I'm assuming that that cable is sticking because during this high idle when I try to move the 1) You own a workshop manual covering the SU HIF-series carburetors. As they aged, all that flexing would make them lose some of their ability to travel for the full range needed to operate the choke plate. Rebuilding the Carburetor. Sticking due to dirt and other foreign matter. no smoking whatsoever. Your problem could be: The butterfly shafts are worn in the carby body allowing too much air to get in and tuning impossible. I've noticed two parts that are just waiting to laugh at you. 17. 3. When I first got my 240z it was running way too rich. If that doesnt work it could be either the fuel pump or carb. I have about 30 hrs on my Kohler. The choke blade should not be 100% closed when setting up the choke adjustment. Well, the spring loaded choke return piece on the top had busted causing the choke to be stuck closed, and it isn't a replaceable part, it is pressed onto the carb. 0625] feeler gauge between the knob and the dash before pulling the cables taut at the carburetors and securing them. Subject: SU Carb Jet Sticking > I have recently discovered that when I start my TR3 that after I release the choke that the rear carb jet does not fully seat to the adjuster nut. Check you dip stick/plunger on the top of the dome. The bubbles make the fuel mixture go very lean so it may sputter and run bad or may not start. If you are still running rich, the problem is in the TSC itself. pull throttle back setting choke. Go to a local GM dealer and talk Then snug the carb rails, then while moving the choke tighten the butterfly screws. There is an orifice on the side of the Stromberg carburetor that draws gases from the tank via the charcoal canister and from the crank case. Electric choke uses the same type of coiled spring cover as the one in the older style engine-heat activated choke that relaxes the spring, uncoiling as it is heated. Fewer people can drive a “stick” shift these days, mostly because the demand ( or take-rate as the manufacturers call it ) is so low, and consequently there are fewer cars to learn on. On the Gravely, while mowing the absolute last lawn last year, it just died. The manual states that I The manual choke should operate on all 3 carbs with a linkage that pulls down the main jet diaphragm adjuster, i. Could be my first answer, a vacuum leak, the heat riser, or a stuck power piston in the carb. front and back it looks like, or just front or back. The running carb here: https://youtu. This occurs because the damper's slowing of piston lift speed increases the depression over the jet hole. The result is extra fuel being drawn into the air stream. Review the article on Choke Adjustment. Assemble the carburetor by putting the clean components back in place again. Once the piston is free it works as expected. SU Choke Return Spring -----Presuming your SU carburetors are maintained and in generally good working order (which is enough of a subject for another article), this article is intended to help in making certain your choke will work properly for you in the next cold season. You need to figure out if it's the handlebar control, the cable itself, or the choke assembly at the carburetor that is stuck. Observe the pump jet in the carburetor, and with your hand, work the carburetor throttle to the wide-open position. If you find your diaphragm pucks are sticking too, youll have to polish them. . check wear marks on it. . It went like this: 1. after you get done, spray some WD-40 in the area where choke go into the carbs and then the chokes. If no lifting pins take off the air box and lift the piston with your finger. Firstly, for Google, the choke heat tube is sometimes called a choke tube, heat riser tube or choke stove pipe. Listen to the engine note while you do so. At 07:10 PM 5/9/05 -0600, Earl Chilton wrote: "You mention that SU-H4 carbs with the side float will at times, have a minor leak. The choke is supposed to do two things; the first half of travel moves a cam on each carb which opens the throttle, for warm up. The snorkel, placed at 8 o'clock slides past the choke plate fine but, after reinstalling the air cleaner housing, I discovered that I needed to modify the velocity choke assembly by drilling the dust cap and inserting a screw as described in the instructions to get the choke plate to This item DP 0102-003 Carburetor Choke Starter Set Rebuild Repair Parts Kit Fits Yamaha Grizzly Rhino 660 DP 0102-002 Carburetor Choke Rebuild Repair Parts Kit Compatible with Yamaha labwork Carburetor Choke Cable Plunger Cap Kit Replacement for Yamaha Grizzly 300 350 400 450 600 660 1978 mgb zenith stromberg single carb, manual choke. Earlier SU carbs needed the needles and jets to be centered but in 1971 the spring loaded needles were introduced to promote fuel flow from the float chamber. Gently tap the needle inward (usual movement about 1/8″). it could need to readjusted or replacing. tilly carb kit - clone -. D. It contains a pair of tubes and wires for balancing the carbs, a jet adjustment wrench, and a (completely useless) “jet centering” tool, which may be seen peeking out of the plastic pocket, just to the left of the jet adjustment wrench. And I never used the manual choke on my K code Mustang either. Jump to Latest Follow Status Not open for further replies. If it isn't the piston is sticking. -some go to the trouble to hone them out, others just toss the whole carb. This is aggravated by alcohol content in the fuel. * Your choke looks like it's not adjusted correctly - when the choke is not in use the screw should not be in contact with the heel of the mechanism. The only fix I've found is to lift the bonnet when engine is warm and push up the piston/choke manually! HS4 on a Triumph Spitfire Mk3. 2) If that's OK check the jet (red bit on the bottom). It has an automatic variable choke rather than a simple choke. 64) with connection for the choke A carb and choke cleaner that is designed to maximize carburetor performance. The choke blade should pop open approx. got a new cable but when trying to disconnect at carb, it was the plunger that was stuck. I’m guessing it is open about 1/10 to 2/10 of an inch. Connect the choke cables at the carburetors so that 1/16 inch free play exists at the choke knob on the dash before the carburetor jet levers start to move (put a 1/16” [0. The one problem I have is that the replacement cable I had to use to for the choke does not allow me to adjust the cable according to the service manual. free it from gum and built up. 403 Followers · Personal Blog Binding I am not sure it feels as if the there is a little play back and fourth in the slide/valve, when it stick shut i only have the butter fly that moves(so go maybe 5MPH), and the times it stuck open I have to work the choke to get it moving then it pretty much full throttle or its gonna die. . Have someone move the choke lever so you can see if the choke moves. Fortunately, there is a system for understanding the size of the carbs. That way you only have to replace the choke cables and plungers instead of the whole carb. Carb is sticking. D) Fuel Pumps. Hold the piston down with a pencil while you tighten the locking nut. Once you close the choke, reinstall the air filter and housing onto the carburetor. carburetor(s)) is the key to tuning the SU carburetor. Tuning – much easier than the two carb set up as you have 2 cylinders fed just from one carb. hopefully you'll dislodge whatevers in there. Tried of hard starts or a sticking choke? Upgrade to an electric choke and make your life easier! We offer Electric Choke Conversion Kits and Hot Air Choke conversions. 940 x 1. Take off the air cleaner housing so you can see the inside of the carb. the choke does 2 things in a particular order - the first half of it's travel will lower the jet, the second half of the travel should open the throttle a small amount. The mixtures screws on each carby are not set equally, so one carb is richer/leaner than the other. A closed butterfly on any carb should stop the engine. . Jake warned of little parts that can easily be lost. However, it came on as if the throttle was stuck at full open. Adjust the choke cables as follows: a. The Choke Plate will respond and return to rest as you have set it—at a loose closure. F. Anyway - here is a few snaps - hope it helps. I ordered a pack of springs from McMaster-Carr (p/n 9271K7). A wee tip for you ; Get a length of the rubber petrol pipe about 8 inches Edelbrock carb sticking at idle. Harley-Davidson, Cruiser, Chopper: motocykle, subkultura. If so, pull the choke out a little. Also, check in a manual for a thermostatic choke opener. Fixing DRIPPY SU H-Type CARBURETORS -- CB-106. The individual butterfly's are not adjusted to be matched at idle. The following should be checked on the engine prior to setting up the carburetor to determine if the situation will lend itself to optimal timing, or I have installed the snorkel on the Honda GX-390 engine powering my Briggs & Stratton PowerBoss generator. Jump to Latest Follow 1 - 19 of 19 Posts. Just as in a SU needle catalog, we first need to have accurate measurements of the needle (needles, if a multi-carb engine) before starting any mods. The mixture screw is all the way to the bottom so if anything it should be running rich. 15. clean the area where the chokes go into the carbs with carb spray (I like B-12 Chemtool Carb spray) Then clean the chokes with carb spray. one of the needle valves kept Take your mower to your dealer, There is a service bulletin addressing your problem with sticking choke, Your unit should still be under warranty so let them repair it at their expense. Now use a pencil or soft metal rod, such as a stick of solder, to push the piston right down. It usually happened on the front carb shortly after a choke start. I called around a couple local bike shops to see if they had a working choke plate. . A bad or sticking carburetor float causes engine problems. Joined Apr 13, 2012 · 48 Posts . Choke Units and Thermos. D) Fuel Pumps. :) It appears that my choke on my 99' gsx-r 600 will only pull back about 50% of the way to fully open. Carburetor: SU Technical Info & Links. I'm sure others will contribute to this but just to get as many opinions as possible search through the archives. The latest is the automatic (sic) choke on the Stromberg carb. , a drop of ATF. . Be sure there is oil in the dashpotson the carburetors for a smooth idle and to prevent hesitation on acceleration. So as following, some unique features to determine the type carb you have. Saddleback Cars. There is a either a rod to bend or a screw to turn to adjust that opening. Picking it up tomorrow. 1/8″. But,,,, before you pay out your *** for unnecessary shop work check out prices for a new carb or fuel pump. Watch for certain signs and symptoms if you suspect the carburetor float Loosen the screws that hold the choke housing on the carburetor. I thought I had pushed the choke down before taking off with my buddies but as I rode about a 1/8 to a 1/4 of a mile, I could tell the choke was still on as the bike warmed up and started to run super rich. The SU carb is also sometimes referred to as a variable choke, constant vacuum, or constant velocity carburetor. I took my SD 54 to the dealer three weeks ago and it turns out they replaced the entire carb. Re: 81 CB650 carb and choke problems « Reply #9 on: April 27, 2012, 03:15:24 pm » I took the carbs off checked the main jets and they are still clean, Floats seem fine, choke plates are all in unison, throttle plates move in unison. e. clogged or firred jets. 8184A Update on my auto choke issue. The individual butterfly's are not adjusted to be matched at idle. The best way to clean the linkage is with a good quality spray carb cleaner. Was running on a couple of cylinders like it was being drowned. Thank you for watching. You don't have to remove the carbs, just take off all of the airbox etc remove the black plastic trim piece on the left hand side of the bike (as you're sitting on it) then remove the choke plungers, it's a bit fiddly but not too difficult, once removed give the brass plungers a good old polish with some metal polish also if you're confident enough you can undo the cable from the plungers and Adjust rear carb Throttle Adjusting screw to the same airflow reading you saw on the front carb. This kit does not come with instructions. A variable choke orifice is obtained in the SU carburetter by the vertical movement of a close-fitting piston (1) positioned above the fuel jet in the centre of the body casting. Sonya, stick with the SU's. Hot carburetors cause fuel to bubble in the base of the carb around the main jet. The method listed below seems to work best for dual carb XK's that I have worked on. WD-40 and The chokercontrol can be hard to get right due to tensions in the bracket leading to a sticking choke. Electric Choke Thermostat Replacement for Edelbrock 8509S Carter AFB Carburetor Marine #809066. A surcharge of £100. 2. The most common type of SU is the HS. I can raise the throttle and it still says in choke mode. Posted by osoksos on Dec 03, 2010. The most serious fault on most old SUs is wear in the throttle shaft area. SU & Zenith-Stromberg Fuel and Carburetor Symptoms & Diagnosis Before adjusting the carburetors, verify that the following items have been checked for proper operation. SU Carburetors is the web presence of Island Automotion Ltd. Carburetor: Early Choke Cable Rebuilding. The second choke opens when you get to about 5000 RPM, and it feels like a poor man's blower cutting in. the top of the nozzle with the choke off that carb will always run very rich. Another common issue is the carbs that idle well but lean out at speed, or run well at speed but will not idle. Datsun 240Z & 260Z SU Hitachi Rebuilt Carb. Replace. The idea behind that is that as the engine warms, the thermostat will open the choke automatically. Once this was fixed (at additional cost, of course) everything worked perfectly. Rebuilt the SU HIF carbs on my 1974 MGB, mounted them back to to the engine. ,,either on the brass plunger or carb body port itself. Turn Idle Adjusting Nuts equally for "best idle" (fastest smooth idle). Have you balanced the carbs to each other with the throttle linkages and fast idle screw. While you are under there, pull the throttle linkage to the full open position. I have had them apart numerous times, the surfaces are all clean with no v In this video, I model how to inspect and fix sticking fuel enrichment plungers found on many Mikuni carburetors. Luckily for you, a dirt bike carb is not a Quadrajet carb on a Chevy 350. SU Carburettors The SU carburettor is a relatively simple design but has proved to be very effective. Your problem is could be one or more of those things. thats what I was trying to say,,, 4 cables come out, 1 goes to the oil pump, and the other 3 go to carbs,,, for you to know that your oil pump cable and 2 of your carb cables pull fine but your mag one doesnt, you evidently have your splitter apart (box in your choke cable). It has a Mikuni B48-34 butterfly carb. The 'accelerator pump' of the SU. Lubrication of the carb linkage should only be done with silicone spray. There is a detent on the shaft that holds the carb in starting/fast idle position until the first time the throttle is opened, then it snaps back. Have a friend or a shop do it. Has Here we have a photo of my ancient PSW Tool, which is designed for tuning SU carburetors. Don't really care why at this point I'm just glad they fixed it. question is when i put the new plunger kit in, should a lube be AUD434E - MGB 1972-1973 PAIR OF HIF SU CARBURETTORS - RECONDITIONED. Integral Choke Systems (1975-1981) Remove the three screws holding the black choke cover to the choke housing and remove the cover. Choke sticking: If the choke linkage is sticking the nozzle can stay down when the choke is off. . With the engine warmed up, pull the wire off the switch. The linkages on the side of the carb need to be clean and not all covered with grime and crud. Carburetor: Late Choke Cable Rebuilding. When you need a part for your Jaguar E Type - we are the people you will want helping you. I'm discovering the later Midgets have some interesting quirks the earlier ones did not. SU Carb Linkages and Return Springs. Take off the air cleaner & look at the choke plate. SU Carburetors. This will cause a small puddle of gas on top of the nozzle. Bike CV's often not 'damped' like an old car type dash-pot SU CV carb, the diagphram is worked both ways, vacuum above balenced by vacuum below, from pitot tubes either side of the main choke. Vacuum from beneath the venturi in the carburetor has drawn the piston down in the choke housing keeping the choke butterfly open once the engine has reached operating temperature. So, while lubing the choke it is advise able to also do the butterfly shaft. Just make sure the butterfly isn't binding on gunk building up on the inside of the TB and you should be good until you can get a better carb, such as the Weber 32/36. Best practice is to remove the old brass floats and replace them with the modern nytril ‘Stay-Up' floats now being offered by SU. I assume thats not right? The springs on the sides look ok. Unfortunately these numbers are not cast into the carb. choke cleaner is highly flammable. 541 likes. Either they didn't have 'em, had busted ones, or wanted to sell me a whole carburetor. SU carburetors have a minimal number of moving parts and are easy to tune, providing of course you understand the operational principles! It is the intention of this article to help clarify those principles in the hopes that many owners will be able to tune and maintain their SU carburtetors aided by better knowledge and less blind experimentation. Many suspected carburetion issues are actually caused by faults within the ignition system, making this the first place to look before making any carburetor adjustments. Choke is stuck in Carburetor – See pictures. Discussion Easiest way is to remove the carbs and take the chokes out there is 2 small phillips head screws that hold the chock bracket in place. YOU NEED TO GET THE BAD ONE OUT>start pushing and pulling use WD 40 if needed. I thought my float needle valves (older Crose jets) were sticking closed for a couple of years. CHOKE ADJUSTMENT on the MGA -- CB-102. No heat shield either. So that sucked, but I got a good used carb on eBay for $25 shipped. Many issues can cause this symptom, but sometimes improper choke operation is Maybe someone has had this issue before and can help. Solution is to pull the choke full out, give it partial throttle, and crank it up. The S. This kit is to convert a carburetor with a hot air choke to electric. Don't know what it sticks even when not installed on the engine. Using a ruler and a fine-point pen, start from the mounting shoulder and make fine lines across the needle at precise 1/8th inch increments. This choke heater is what opens the choke when the engine is warm. A couple of pumps on the gas pedal to prime the carb and a well tuned Ford will alway start without hesitation. If a little more manual choke cures it, then it just needs choke for startup, which is normal. That’s because the carburetor has been the crowned jewel of some of the most revered small blocks, big blocks, HEMIs, and six-cylinders to ever grace our street rods, muscle cars, and vintage haulers. E. SU Carburetors is the web presence of Island Automotion Ltd. damn clone carb choke shaft. Rebuilding a carburetor is a daunting task when you first look at it. Tighten the clamp bolt of the throttle shaft lever at this position. Can’t speak to that carb model, but on my truck’s autolite 2100 the choke plate is fully closed before starting the engine , then slightly open when the engine starts up and is cold idling. I didnt want to lift the tank and take crap The choke blade should be completely closed at this point. After cutting a yard I drop it to low speed to cool down on the trailer while I lock it down about 30 seconds or so. It IS NOT cast in stone. The cable is sold as a single item with a typical outer, but has a wire with pre-bent ends as the cable itself. clone carb butterfly only. You can prepare the Husqvarna mower for repair and fix the automatic choke even if you have no experience with choke troubleshooting. warning wear safety glasses when cleaning choke. The metering nozzle, the black plastic part you see go up and down when you pull your choke, has to be able to go up and down smoothly, and return completely with no drag. It's supposed to operate when the engine is cold, but if it's stuck or burned out, the mixture will be weak and the scooter probably won't start. . If the fuel level is higher than the top of the nozzle with the choke off that carb will always run very rich. For both carbs at the time of rebuild the parts upgrade is $45. If you are on SU's first of all check that they are able to close, also that the choke is returning fully Similarly with Strombergs, but with the latter check the diaphram for holes. · Set the idle screws: Picture 20 – Idle adjustment 1) Fast idle screw (not a factory screw shown) 2) Idle screw 3) Space should be about 3/32 inch ZS Choke Page 13 of 16 The choke cable on a large frame Vespa runs from the choke lever in the center of the frame below the seat to the carburetor on the right side of the engine. There aren’t too many other things that will give you an over-rich running condition…aside from a loose or fallen out jet…I’d start at the choke if I were you SU Carburetor Linkage - Since 1976, Terry's Jaguar has been in the business of supplying a wide range of parts for Jaguars - everything from XK120, XK140, XK150 and all XKE / E-Type Parts models right through to the latest Jaguars on the road. To test for this, spray some carburetor cleaner on the outside of the throttle shaft; carburetor cleaner is non-combustible, and if the engine speed drops, it means some of this is getting into the air stream from outside the carburetor. " They could leak at the rubber grommets between the float chamber and the carb body (banjo bolt mounting). Sticking due to deformation (bulging or caving) of suction chamber or suction piston. I oiled my choke cam with engine oil and after a while it became sticky as in your case so I sprayed it with carb cleaner and it has been working fine since. You test the diaphragm by applying vacuum to it and seeing if it actuates, and to check for leaks. Bent jet needle. SU Carburetors is the web presence of Island Automotion Ltd. Start the vehicle. . 1970 through 1987 Quadrajet, Electric Choke Kit. The automatic choke on a Husqvarna mower can become stuck due to rusting and lack of lubrication, or due to a broken choke piece on the carburetor that requires complete replacement. I have a 2002 350TRX and wasn't used much recent years so the choke started not working/stuck. 1/16 to 1/8" works fine. The rapid closing gives some momentum to overcome the slight stick, the spring does not quite have enough pull to get past the 'stick' when moving slow. NOTE: I have a price list for Rebuilding, Restoring & Bench Testing of SU carbs & Zenith Stromberg carbs on the text only pages. The linkage appears to be free of any binding or stiffness. Your problem could be: The butterfly shafts are worn in the carby body allowing too much air to get in and tuning impossible. Clicking this will make more experts see the question and we will remind The cold-start device consists of a choke lever (3, Fig. If you're lucky and the enrichener cable is still attached (and not rotted) to the plunger, that may help you get the plunger out. The car has the 3 screw SU carb on it. With the plate installed, the carb (Carter AFB 4200) sits about 5/8" above stock height. D) Fuel Pumps. See ACC5062 for carb cable link trunnion also. 4 out of 5 stars 138 $33. If the carbs were disassembled the choke linkage may not have been properly adjusted after reassembly. The power piston enriches the mixture and is controlled by manifold vacuum--not to be confused with the pump plunger. The throttle adjust is still basically all the way out though so still trying to mess with it. I removed the retaining screw on the last part of the choke cable (where it turns into a steel tube) and had enough slack to pull the tube out of the little rubber boot where the cable goes into the carb, and that pulled the Additional SU Carb Resources: The previous information and procedure should help a vintage Volvo owner to get familiar (or maybe even comfortable) with their SU carbs. Please note : This item is supplied on an exchange basis. i double checked everything before putting back together. Move the throttle shaft lever downwards until the lever pin rests lightly on the lower arm of the fork in the carburetter throttle lever. Choke lever lowers jet to enrich mixture (not shown) 19. Time came yesterday to try and fire it up for the first time and after some playing around it finally did. Drifthopper · Registered. Want Answer 0. SU. Initially I carefully cleaned each carb and made sure they rose and fell perfectly (rear one was sticking and needed jet centring) and then using calipers I set each of the jets to be the same distance down from In both types of SU carb it is done by increasing the amount of fuel for a given amount of air (rather than reducing the amount of air for a given amount of fuel as in the other design of carb) and so is an enrichment device rather than a choke. The sizes describes the carb's diameter after the throttle plate on the engine side. yes. In the process, if you noticed a jet is not up to the rest position, then check that the jet tension spring is attached to the jet lever and carburetor body. Why? I don't know unless there was a TB or something on the carb. The most notable difference between Type H-4 Volvo and MGA carbs is that the Volvo carbs go on the passenger (right) side of the engine, whereas the MGA carbs go on the driver’s (left) side. SU & Zenith Stromberg Carb Rebuilding & Restoration. The mixtures screws on each carby are not set equally, so one carb is richer/leaner than the other. If a triple carb has been sitting for a while and the "choke" (enrichener) has not been operated for a while, chances are you may be looking at a brass "plunger" that is now stuck in its little "hole" in the carb. Maybe your needles are sticking open or closed. SU Carburetors. Quick ref, while choke in open position and throttle on stop screw. If none, replace fuel pump. Pull gently again with your fingers. Choke Units and Thermos. Welcome to SU. I did some gaskets and replaced a couple things on it that came with a refresh kit. This breaks the needle loose as well as lubricating a dry area of the shank. if you don't know that much about those, don't try to monkey around with it. The needles are actually loaded to rub on the jet on the engine side. Check your carburetor manual or guide to find that rod or screw. Thanks, it did seem a little stuck on the return. carburetors, particularly if your car was equipped with vacuum retard. 2. Gumout® Carb/Choke & Parts Cleaner quickly removes these deposits from the inside and outside of the carburetor to improve engine performance and fuel economy. Rob Post Edited (Aug 24, 1:28pm) The carter bbds are POS's. Carburetor: SU Adjusting - Keith's Latest Writeup. . If they have sat for an extended time they can also become stuck on the centre bolt in the float chamber. So you may have to determine if the alternator is feeding power to it. I disconnected the linkage and pulled the jet to clean it and lube the lower portion with The cam that operates the choke butterfly may be sticking too, it should be clean and only very lightly oiled with a light weight oil e. Various SU Carb Video Links · Reinstall the choke back onto the carb, using a new gasket. Automotive and Marine. g. Rebuilding consists of New: Throttle shafts & bushings, Throttle discs, nozzels are rebuilt with new jet tubes, upgraded nozzel to float bowl fuel hoses with upgraded hose clamps, meetering needles, floats, float valves & pivot pins, air piston return springs & all Shovelhead SU Carb. check and adjust fast idle cam for free movement. Remove the high tension wire from the center tower on distributor cap and ground. We’ve made thousands of dyno pulls in our time. E. Can’t speak to that carb model, but on my truck’s autolite 2100 the choke plate is fully closed before starting the engine , then slightly open when the engine starts up and is cold idling. SU carburettors were a British manufacturer of constant-depression carburettor. Carbs - removing a stuck "choke" plunger. The “choke” on the rear carburetor was operating properly. There is an easy test to see if the thermostat switch is the culprit. I have created a spreadsheet comparing the normal AAT jet needle {Spring type } for the SU HS2 carb against 3 other RELIANT NEEDLES . The jets in both carbs are so "tight" that they are very difficult to move by hand, and they will not move at all when I pull the choke knob. Carburetor + Air Filter Box Assembly Housing Kit For Polaris Predator 90 Manual Choke 90cc Carb Sportsman 90 Yamaha JOG 90 100 90cc 100cc 4DM Scrambler 90 2001-2003 by LIYYOO 4. If rivets are used, drill out the rivets. I unhooked the choke cables and the air flow dropped down to between 15-20. The needle jet collar and the pilot screw O-ring both tend to stick in place. The float in the carburetor regulates the amount of fuel or gasoline which resides in the reservoir. I have chosen to put my effort into dellorts rather than sort out my HS4. SU carburetor full form is Skinners Union carburetor. Quickly dissolves carburetor deposits such as gum, sludge and varnish to improve fuel system performance and enhance fuel economy. Please use our product search boxes below to find your Carburettor, Fuel Pump or spare part for your vehicle or have a look around our store to find a range of accessories to fill your needs! The SU carburettor is simple to strip. 88 The choke being out and improving the "running" indicates a lean condition. If it comes out and can be smoothed out as well as the carb body then check for adjustment and your good. If the mixture is correct the engine speed should rise slightly for a moment, then return again to normal. We are The Worlds Sole Manufacturer of Genuine SU Carburettors, Fuel Pumps and Spares. I noticed at the end of last year that my choke has been sticking. That is, until . It virtually always comes down to the two things I mentioned - once in a while the spring will get pinned between the body and the metal arm that pivots. the only way to adjust SU Carbs as I have used different methods of adjusting on other English cars and Swedish cars fitted with SU's or cars with the Japanese version SUs (even a Harley fitted with an SU from an MG). SU Carburetors. As far as getting a replacement, I have about a 0% expectation that you can buy that part from any normal commercial vendor or dealer. Check your carburetor manual or guide to find that rod or screw. About 5 minutes it kicks down. It is strongly recommended that you understand the theory of operation and the mechanical layout of the carburetor before you start. That will stop all the binding unless you didnt perfectly clean the orifaces when the choke butterfly stems rotate in. You want to speak with Nick Papageorge (owner) 25701 Taladro Circle, Suite F Mission Viejo, CA 92691 Manually open the throttle using the linkage on the carb. Example: HS4: 1" + 4/8" = 1 1/2" = 38,10mm. Then you can slide the mixture jet back in, and hold it in by reattaching the choke control arm which is spring loaded, meaning the mixture jet will be held in place. The mixtures screws on each carby are not set equally, so one carb is richer/leaner than the other. For high fast idle and slight sticking unscrew fastidle screw. it will tell you how to clean choke. the fuel jets are so small, those frequently get clogged as well. Steve, I live too far away to help unfortunately, however I hope this info helps. It is located under the dash somewhere above the accelerator. Carburetor: Weber Install. The first letter is an H or a V, which stands for Horizontal or Vertical. I’m guessing it is open about 1/10 to 2/10 of an inch. SU Fuel Pumps - Timeline and Information; Fuel Pump Points Sticking; Does it matter which Fuel Pump polarity I order? Carburetter Maintenance and Settings Choke Units and Thermos. Today's post is about my recent rebuild of a pair of H-6 carburetors from a Triumph TR3B. When releasing it, I can always subsequently push the lever up a little bit further with my hand. Re-attach the vacuum hose to the pulloff and the carb. If in the course of this familiarization additional questions arise, help is (almost immediately) available by posting to the LINK: Brickboard Forum . I am finding the choke levers on my frogeye (standard SU's) dont quite fully release, particularly on the rear carb. A number of good-quality manuals dedicated to the SU are available and are highly recommended. When its stuck I have to gently ride it out for about 5 minutes while its in the high idle position. If the car had been laid up for a long time any of the throttle or choke parts could be sticking, either open or closed. Hank. This may also be a good chance to inspect for damaged components. It was headed to the dealer and after sitting in the warm If your choke sticks, or doesn’t move properly, it can induce a flooding situation even if you follow the right steps for starting. I’m obviously going slow on this project and if the PB doesn’t free it, I’ll try some concetrated heat on the choke plunger next. If it is not taken care of when it is only sticking slightly, the dirt can build up until the choke is stuck solid. On the passengers side of the carb is a diaphragm that is called a choke pull off. Tracked it down to my rear choke sticking partially on. The choke blade should be completely closed at this point. Your problem could be: The butterfly shafts are worn in the carby body allowing too much air to get in and tuning impossible. carburetor and the engine is turning over on the starter OK, it's possible that the electrically operated automatic choke has failed. Your choke is stuck shut. I was able to drill out the post (5/64" drill) and push it out. Most the time it sticks from a rough surface / scratches . Auxiliary Enrichment (Thermo) Carburetter ; Automatic Enrichment Device (A. it takes significant pressure with your finger to start it moving. Correct. The reservoir of the carburetor is where the fuel is sucked into the intake manifold. Connected throttle cable and choke, the car started right up with choke pulled out let the engine run for a few then pushed choke back in and the car stalled immediately, crushing my spirits. After much delay I have relaunched the Carb. The individual butterfly's are not adjusted to be matched at idle. I have also compared the standard needle found in the MINI SU CARB against the normal AAT jet needle {Spring type } . In reality it is quite easy. SU carburetor is a constant depression or constant vacuum type of carburetor. 00 for the pair with additional costs for fitting. The choke on the rear HS4 SU carb keeps sticking! At cold the car starts fine with full choke but I've discovered that lumpy and uneven running is due to the rear choke (orange/red coloured covering) not returning up into the piston chamber when choke cable is released/pushed back in from the dashboard side. Bent plunger rod. test starting. . Crank over engine – if there is no fuel discharge from the fuel line, check for kinked or bent lines. I talked to so called Carburetor experts who told me to chuck the 240z Hitachi carbs as they are no good and will always run rich etc, their suggested cure was to buy British su's @ $800. Overtime, carburetors and choke valves can become clogged with gum, varnish and dirt, affecting performance. 539 likes · 3 talking about this. The brass floats used in the H and HD series carbs were prone to stress cracks along their sides. SU > SU Carburettor photos and information Posts Welcome to the relaunched Carb. the lever on the bottom of the carb that contains the mixture adjustment screw. SETTING THE FUEL MIXTURE The carburetor most probably dirt stuck or gummed up inside it. Help: I have a sticking SU carb piston problem. eng rev's to high/low,sticks. The biggest remaining problem is the choke is stuck in the closed position. Carburetor: Chokes Sticking? - Scott Lindley. So I still have to manually push the jets up when I have had the choker engaged. SU Fuel Pumps - Timeline and Information; Fuel Pump Points Sticking; Does it matter which Fuel Pump polarity I order? Carburetter Maintenance and Settings Slacken the large locking nut above the adjuster nut on the jet where it enters the carburettor body. U. Pull the air cleaner and look at the carb…make SURE your choke is working properly and more importantly…disengaging properly…methinks you have a stuck/malfunctioning choke. . Spray some lube in the hole and also lube the o-ring on the choke plunger on the end of the cable. E. Moss part numbers 211-305 and 211-345 are two such guides I recently rebuilt a pair of SU Type H-4 carburetors for an MGA that had an inoperative “choke” and fast idle mechanism on the front carburetor. Apparently this is the first my dealer has heard of it and is clueless. This post does not discuss all the steps necessary to rebuild Type H-4 carbs, but rather focuses on things that differ from Type HS carbs, which have I have AUD 135 SU's (fixed metering needles) on my 65. The carb is from the CRF80 that I'm current Balky during warm-up; may spit/pop through the carburetor when trying to drive: The choke spring tension is not tight enough and the butterfly is opening prematurely, creating an excessively lean air/fuel ratio for the engine temperature. Also make absolutely sure your needle isn't bent in the jet bore. Engine revs to 5000 when ignition switched on. If you cant get your splitter back together good I would get a new one. If the switch is faulty (stuck closed in this case), the TSC should shut down and the engine run properly. There is a vacuum passage from the choke housing into the carburetor to supply the unloader/pull-down with vacuum once the engine starts to crack the choke plate open to prevent the engine from being starved for air from a completely closed choke plate. E. It looks good, works even better, and simplifies the look of the carbs. Once you have become familiar with the process, you will find it easier the next time. Remove the carburetor from its position carefully and dismantle it. I just changed my plugs and it starts VERY easy even in the cold without choking it. Correct. Choke – Gary Herbold and others say that you only need to choke the middle and rear carbs using standard parts. This completes choke adjustment for a divorced choke carb. Give it a wiggle to see if it moves OK. If there is no pin, lift the piston with a screwdriver. The second half pulls down on the needle seat to enrichen the mixture, for starting. Also no expert with rockets. 00 excl VAT will be charged in addition to the unit cost if it is supplied in advance. You should observe a healthy squirt of fuel from the pump jet. 1/8″. Carb. The rest of that carb will work fine, but the choke will not. I have restored a Yamaha Excell340G (1983) and have it running very well. With correct amount of choke it should run smoothly at a fast idle. 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. You pull on the cable and the end of the choke plunger breaks off where the cable attaches, leaving the choke plunger seized and stuck down in the carb (likely). The mixtures screws on each carby are not set equally, so one carb is richer/leaner than the other. If your lucky, mix at twice the rate suggested on the can and run for at least 5 min that way you'll have the solution in the carbs to sit overnight. I’ve disassembled as much as possible - enough to get it soaked in PB Blaster, but it hasn’t budged yet. If you don't know your own strength, be aware that your carb is cast aluminum and can crack or gall if mishandled. Note: Some carburetors have a "suck valve" on the choke blade. The best way to clean the linkage is with a good quality spray carb cleaner. These instructions do not cover tuning SU carburetors. Twice now when cold we engaged the choke 1/2 and full, and the choke stayed open and flooded the engine. A stuck choke can also prevent you from closing it fully to allow the engine to start properly. February 23 ·. Their designs were in mass production during most of the twentieth century. Island Automotion specializes in the restoration of SU and Stromberg carbuetors. SU Fuel Pumps - Timeline and Information; Fuel Pump Points Sticking; Does it matter which Fuel Pump polarity I order? Carburetter Maintenance and Settings Like many automotive carbs, the SU has a fast idle adjustment that accompanies the choke. take car to garage let them check the automatic choke out. It can be a source of airflow affecting the mixture when worn. A couple more light dabs on the gas during the first 30 seconds and the motor will then idle on its on. High RPM's You can get the plungers out by running a self tapping screw into them and then using the screws to pull the slugs out (you can get a hold of them with vicegrips). Within a few seconds of getting it running, the choke engages. On the same spindle, outside the housing (5), there is a cam disc (9, Fig. ZTherapy 240Z SU Carburetor Spotter's Guide This is not a carb-It is a boat anchor! June1972 240Z to all 260Z's (US) Flattop "Hitachi" Evil things, these square mouthed carbs. The back piston stick at the very bottom. If you have these carbs on your 240Z-trash them and get ZTherapy SU's. Carburetor: Bent Needles 101. g. The piece you're missing is part of the choke system and because of that, the choke will not function on that carb. There were three separate problems with the carburetor that came together as a “perfect storm” to prevent both the “choke” and the fast idle cam from moving sufficiently. Your problem could be: The butterfly shafts are worn in the carby body allowing too much air to get in and tuning impossible. About the only way to get the engine started is with starter fluid. Skinners Union is a carburetor company established in London in 1910. Clean each component separately and ensure that there is no dust accumulation. While there they replaced the transmission brace also. Check fuel pressure to SU with pressure guage 3-4 psi. Auxiliary Enrichment (Thermo) Carburetter ; Automatic Enrichment Device (A. Rear plug was very black and sooty (but dry), front was A-1. If the choke hasn't already closed, you should be able to see the choke drop closed. Start with the choke in the off position (knob in). Since you started with them tightened clockwise (lean) loosen them (anti-clockwise) to increase the engine speed. Put a little thread sealer on the three screws that hold the choke to the carb. In the beginning, if I gave it enough throttle to open the secondaries, it would temporarily stick causing the Jenni and I tried a nifty trick I learned for freeing up a seized carb. There is a either a rod to bend or a screw to turn to adjust that opening. E. To start on a usual day from cold, full choke, clutch lever in, stab the button and let it fire. The engine would basically try to run on only one carb acting like fuel starvatio. The choke butterfly should be fully open, as the engine is warm. Clockwise, from left: We tested four setups on our MGB engine: 1 1 /2-inch SU HS4 carbs on a factory MGB intake manifold, a Weber 45 DCOE carb on a Pierce intake manifold, a Weber 32/36 DGV on a Pierce intake manifold, and 1 3 /4-inch SU HS6 carbs on a Maniflow intake manifold. Check by reaching under each carb and pressing up to check if the jets have returned to the full up rest position. Preparation Setting up and tuning an SU carburetor is based on the premise that both the engine and the carburetor are in good shape. If this distinctive noise cannot be heard, it usually means that the piston is sticking in the dashpot, or the jet has not been correctly centred. I added the Electronic Points. Do you have Link to the bulletin. buy a can of carb choke cleaner. It's job is to crack the choke open a bit when the engine fires up cold, to keep the engine from flooding and dying. the choke isn't the problem, the plates are physically sticking. This is intended to grow over time to become a very useful resource for all models of SU Carburettors, as fitted to many British classic cars such as Jaguar, MG, Morris, Austin, and more. su carb choke sticking