Archived. And of course make sure that it's properly connected electrically to the connection on the coil where power is provided (the + connection) -- the lead can break off. Carburettor jets Solex 34 PCI . All three of these jets can be changed. (Solex jets are marked with the hole size in mm, so a X127.5 jet has a 1.275mm hole - I'm not sure what numbering method Mikuni use). Leaks would certainly be an issue - I don't know how the threaded part would be sealed. If the fuel/air mixture is too lean, the engine will run very hot, stumble, and misfire -- and burnt valves can be the result. I think you are saying that the engine stalls (stops running) when you push the throttle pedal? for IDFs, make the idle jet 1.25 the size of the throttle body. I managed only 22 mpg on a highway (around 50-55 mph), and 19 mpg when I was driving around 60-65 mph. Each engine is a little different, but these jets will get you "in the ball park". (You must log in or sign up to reply here. Remove the brass plug with a hex head on the left of the carburetor -- bottom of the float bowl (all the fuel in the carburetor will rush out). The air correction jet affects mostly the high rpm -- not much effect on low-middle rpm). The idle cut-off valve sticks out the left side of the carburetor on H30/31 and 34 sries carbs (but on the right side on 30PICT series) and has an electrical connector on the end. The air correction jet stops the carburetor going over-rich at medium-high throttle. We need to do some research regarding the adjustable main jet. Thus a size 55 idle jet is 0.55mm, size 125 is 1.25mm, etc. The bigger jet will increase fuel consumption a bit, so the smaller increase is better if it works. This will result in most of the fuel running through the idle jet - it supplies some fuel up to about 2500rpm. The sizes are stamped in tiny numbers on the heads of each jet. Replacing the main jet in is super easy -- just put it in the hole in the side of the carburetor, then put the screw driver in after it and slide it along the 'valley' that runs across the bottom of the float bowl. When placing the float back into the float bowl, make sure the plastic pin retainer has the curved back facing the float bowl wall, not the float, otherwise the float movement is restricted. All suggestions here are just that - suggestions. Post by Red Devil » Mon May 31, 2010 9:04 pm OMG - think I may have some answers here so I'm going to back out the idle jet tomorrow night a little to see what impact that has and also check the fuel cut off … For the air correction jet, larger numbers mean more air flow, thus a LEANER mixture. If it's working, you'll hear a clicking sound as the relay pulls in. "N" on the schematic is the coil. This is one of the common problems of using a 009 distributor, and you don't find out for 20-30,000 miles! The X127.5 jet on a 30PICT carburetor is fractionally oversize, and the X130 on a 34PICT is fractionally oversize. Volume: 1700000mm 3. Carburetor model numbers can usually be seen stamped on the side of fuel bowl. The final bit to disassemble is the accelerator pump. When using the 30PICT on a twin port manifold and any vacuum distributor, change the jets to 55 idle, X125 or X127.5 main and leave the air correction at 125Z. Manufacturer: Classic. In addition, if you have a problem with a 55/60 idle jet, and you have the right main jet, and still have a hesitation regardless of accelerator pump adjustment, you need to play with your idle air bleed (what the fuel from the idle jet mixes with). And I have the by pass air cut off valve (12V thing) on the left side (as same as on the 30 PICT-3, which I have seen on pictures in books, but the by pass air cut of valve were always shown on the right side). The air corrections I have are 125z, 170z and in the carburetor a 135z. Nothing is exactly that linear of course as the jets are all different sizes, but maybe it helps visualise the problem of keeping the fuel flow balanced at different rpm/airflows. When you work out the area of the hole in each jet, the steps are roughly 2% increase in fuel flow for each size up (X125 to X127.5 for example). My distributor is a vacuum advance (with a centrifugal?). In most cases you can just leave the power jet alone. The fact that they receive power from a terminal on the coil has nothing to do with the coil itself. Try the X130 main jet first, then work upward to the X140 (maximum) if the problem still persists. The jet has a slot in the back so it can be loosened with a screwdriver through the hole where the plug was. Have a look at the size stamped on it too. Go down "1" for every 1k' above sea level you are at. The last three carburetors are more sensitive, and so the lack of vacuum advance on the 009 makes more of an impact. The H30/31 is the largest carburetor you can use with the normal single-port manifold. Rob responded - If you still have a vacuum distributor - yes. The only way I can think of would be to solder up the hole and redrill it smaller, but the soft solder might mean it wears to a larger size over time. The three wires could each go up to fuse #12 individually, but that would be very inconvenient. Once the jet is loose it sort of falls on it's side, so then I use the screwdriver to nudge the jet out along the trench to the plug hole in the side (rather than using needle-nose pliers). 81. This is not correct. Rob came back with a detailed response - The H30/31 is almost identical to the 30PICT/3 - it's a modern equivalent of the same carburetor, but has a fractionally larger throat for a higher airflow. I haven't run enough through the tank to get a real idea about consumption yet, but since I don't notice any huge difference in performance I'll probably be going back to the X125 soon. I have EMPI 34 pict 3 on GL1100 55 jet 130 jet idles 1000-1100. 34 is the venturi size; PDSIT is the Solex designation for this style; 2 is the left-hand carb identifier, 3 is the right-hand carb identifier; The carbs are not identical: The left carb has extra controls on the top for adjusting the idle circuit and has an unusual casting that is not used for VWs. The biggest problem I have with it was the fuel consumption. There is enough variation in fuel types, wear and tear on engine and carburetor, altitude and so on that you might need to experiment a little. I couldn't find it in any book. There should be a light smooth coating of carbon on the rim of the threaded part, and a colour change on the outer electrode of grey (at the tip) to black (where it attaches to the rim of the threaded part), with the change of colour on the corner of the bend. So VW chose this configuration. Carburettor jets Solex - Weber. The proprietor of Aircooled.Net thinks the main jet is a size X130, and the idle jet is size 50.) The idle jet sits in a protrusion running down to the bottom of the carburettor, and the power jet sits in a protrusion running up to the top of the carburettor, so it's easy to tell which is which. Look down into the top of the carburetor to make sure that the screwdriver is squarely in the slot in the jet and that the threads line up squarely, then just screw it in (the small screw driver sits deep in the slot in the jet and helps line it up). The other one (pointing straight out to the right side of the car) is the power jet, which feeds additional fuel at high throttle/high rpm. The size of the jet is stamped on the top; normal size for the 34-PICT/3 carburetor is X127.5 (1.275mm diameter hole). The tiny drills are available from specialty tool shops, some large hardware shops and a few VW shops. You may have to get creative about how you attach so many wires to the single terminal on the coil. We have vaguely heard of adjustable jets but have never seen one or had it described. Another question - The car runs terrible but it runs. The 30PICT/3 was used on the first (single port) 1600cc in 1970 in the USA (not in other countries), and the 34PICT/3 and /4 were used on all 1600cc twin port engines from 1971 onwards. Just start off with a larger than normal size (150 maybe) and use the screw to increase/decrease the actual hole size. That's considered by some to be borderline and can cause the engine to run just a smidgen warm due to less evaporative cooling. E10 usually needs a larger main jet and might also need a larger idle jet. 01-16-2016 02:29 AM #3. For a 1776cc engine with 009 distributor, 55 idle, X132.5 or X135 main, and air correct around 80Z should be close to the mark. So I replaced it with a 30 PICT-3 carburetor in a good condition. Soot will indicate the main jet is a little too large. I have main jets: X117.5 and X127.5 and as far as I remember currently in the carburetor is a X125. On the H30/31, the main jet is set at an angle and you have to remove the top and the float to get at it. At the beginning I started to use a Solex 30 PICT-2. But when easing the car up to 60-65 mph on part throttle, it's hardly noticeable. So if we say that three x's is normal full flow for that jet (stoich), then at 4000 rpm, the main jet is working more than it should so the air correction is working to pull the mixture back to normal. I have 4-5 I've collected over the years, and the smaller ones can be re-drilled to the larger sizes. Take the car for a run at a modest speed - say 35-40mph. The jets in Dave's 34 PICT/3 carburetor are - * Main jet - X130 * Idle jet - 55 * Air correction jet - 80Z : I have always heard that the minimum recommended main jet is 127.5. ). ANY SINGLE THING other than stock, Berg Semi-Hemi heads, 009 distributor, extractor exhaust, etc. The speed of the engine (RPM) when it's doing this tells you which jet you need to change. The extra jets given with the kit are a larger 60 main jet and 130 idle jet. Dave jetted his new carburetor as follows: main jet - X130; idle jet - 55; air correction jet - 80Z. Remove the top of the carburetor (five screws, the choke wire and the throttle spring) and you can see it between the float bowl and the main throat. It worked quite well, although the idle wasn't very accurate. Could you help me with the jetting? Revving the engine in neutral will result in hanging RPM’s, or RPM’s will slowly drop back to idle RPM. The modern H30/31 carburetor replaces the 28, 30 and 31 series carburetors and can be used on 1200cc, 1300cc, 1500cc and 1600cc engines with appropriate jetting. Rob's note: When removing the main jet, I use a small glass jar (pickle or baby-food jar) to catch the fuel from the brass plug - I hardly spilled a drop (I just allowed the plug to fall in to the jar), and used the fuel to refill the float bowl later. Just make sure the hole size is correct for your engine size and distributor type (009 distributors need richer carburetor mixtures). On the other side of the carb body you now need to remove the idle jet. If you have a 009 distributor (no vacuum canister on the side), the main jet should be about X130 or X132.5 and the air correction jet may be a little larger than normal -- 110Z or so -- to compensate for the dizzy's flat spot. Solex, Brosol, or Bocar 30/31 should use a 120-125 main jet. Rob wrote in this regard - See our article on Reading Spark Plugs. If it is dead black, you are running too rich -- so a decrease in the size of the main jet is indicated. This is my first post here so I apologize if I posted in the wrong place. For example, when used on a 1300cc engine with a vacuum distributor, the H30/31 should usually have a main jet of X122.5 and an air correction jet of about 140Z; but when used in a 1600cc single port engine, it should have a 125 main jet and a 125 or 130 air correction jet. Originally Posted by wifesbug. Solex 34 pict 3 jet size. As indicated previously, the VW engine actually runs better at fractionally rich settings (ideally 13.8:1 rather than 14.5:1 according to Bob Hoover who did lots of testing), but they are usually jetted a little leaner than that, so the X127.5 is really a minimum jetting for the 1600cc engine. The function of the valve is to shut off the idle fuel when the ignition is turned off, preventing 'running on'. Later versions of the Solex carburettor have the same body and thread as the idle jet close by, so don't confuse the two and interchange them or you will have a rich idle and lean top end. With the air correction jet you have to go 3-4 sizes different to see a real difference, unlike the main jet where one size can make a big difference. An altitude of 5000 feet is roughly equivalent to a one size main jet difference. The air correction jet prevents the mixture going over-rich at high rpm (again, smaller numbers means richer for this jet). If you have a significantly larger idle jet (e.g., 70 or so), John Connolly recommends going down until you can not get a good engine response with the mixture screws anymore. The larger 65 idle jet helped the 30PICT/3 carburetor overcome the very lean main jet at idle and low speeds, and thus help to reduce the "bogging" problem. While it is necessary to enrichen the fuel mixture when running an 009 distributor, you don't want the any richer than necessary since it will use more fuel. 34 PICT Carburetor Combination, Automatic Choke Discussion and Adjustment Procedure. With lean jetting you are likely to need more throttle and have slightly worse fuel economy - using the slightly richer settings I'd suggested above will give you a little more power and a cooler running engine, so hopefully fuel economy will improve a little, but don't expect too much - fuel economy with the heavy Type 2 body is never very good. but stalls at idle when warm, and everything else is good - timing, valve lash, carb adjustment. The only method of getting it exact is to run the car on a dynomometer with an exhaust gas analyser in the exhaust pipe. It provides fuel at low medium revs too, so if it's not working you'll get a rough idle and lean mix at lower revs. This will tell you if it's running rich or lean at speed and then you can set the air correction jet accordingly (smaller air correction means richer mixture - is delivers air so it works the opposite to a main jet. Use a steady throttle - minimum acceleration. I found out the the Empi 34 epc comes with: 1.75.130 main.55 idle.160 air correction jet I don't know what the difference between a 34 EPC and a 34PCT is so I don't know if they would have the same jetting from the … (Some of this material was adapted from John Connolly's article on How to Jet Your Carburetor.). Idle jet sizes of 70 or so will "run" on anything, but they don't run WELL (unless fouled plugs or 12mpg are your idea of "well"). The back one (pilot?) $10.84 $ 10. The soldering and drilling of the Jets can apply to any carburetor! This is a very easy solution to this common problem. On some models (the H30/31 for example) it is angled slightly towards the back of the car. But engine sizes have much more variation, 1200cc to 1300cc is about 8% more, 1300cc to 1500cc is nearly 14% more, and 1500cc to 1600cc is about 7% more. You will see a black wire coming into the positive terminal on the coil from fuse #12, which receives power from the ignition switch, so the valve opens whenever the ignition is on, allowing the idle fuel to flow. The condenser is 1 237 330 251. If the engine is stumbling at 2000 RPMs and lower, then you need to richen up your idle jet (go to a larger size) - but check carefully for air leaks around the throttle shaft first!. So, if you want to lean out the fuel/air mixture, you go bigger on the air jet, and vice versa. Check the jets in the carburettor - if you have a vacuum distributor (you didn't say which sort you had), then the 34PICT/3 carburetor should have a 55 idle (right side of the carburetor. Others might find that the 30 sized carburetor on a 1600cc engine works better with a larger X127.5 main jet. So with a vacuum distributor, using a 55 idle, X130 or X132.5 main and about a 100 - 120Z air correction jet should provide good mixture for a 1776, without affecting fuel economy to badly (fuel consumption WILL be a little higher with the larger capacity though). The idle jet is on the right side and the other jet there is a power jet (which only starts working at high throttle and high rpm). Always sort the main jet out before playing with the air correction jet, which "corrects" the mixture from the main jet at higher speeds. That means that the jetting requirement for any VW using ethanol-added gasoline/petrol is different to those using straight hydrocarbon gasoline/petrol. Change the main first and do a plug read as above. If you have a 009 (centrifugal advance) distributor, you may find that the spark plugs still seem a little dry/burnt looking at medium speeds , or the car lacks acceleration in the mid ranges. I remove the top of the carburetor, then run a thin screw driver (which avoids the coil) through the plug hole to get to the jet. The effect is clearly noticeable from 3000 RPM upwards (just under 60 mph), and probably a little lower than that. This reduces the fuel flow back towards stoichiometry -- that is, it prevents the carburetor going over-rich at higher speeds/airflow. Aircooled.Net has them, and I think Gene Berg in the US has them too. To be honest I have never messed with the stop or curve in an 009. They might be available individually or in a set. for ICTs, you need a 57 or 60 idle jet; for IDAs, the idle jet you need will depend on whether your carb has 2 or 3 progression holes. Regarding fuel consumption as a function of jet size -- The 1600cc Beetle should get about 10-12km/l (24-28mpg). FAQs Ask a Question. See the discussion of jetting with the 009 distributor below for needed revisions to the jetting of the 34 PICT/3 carburetor in this application. all make a difference in how our old engines run, so you might need to experiment a little. 34 PICT Carburetor Combination. buggyman. What are some indications of a lean pilot jet and/or screw setting? The fiddly bit is pulling the jet back through the hole. If your solex 34 pict 3 starts and runs fine when cold. Jump to Latest Follow 1 - 12 of 12 Posts ... And going up a size or 2 on the idle jet usually cleans it up some more if done together with the timing Click to expand... 32 total, total is all I ever check. They looked perfect. The 28PCI and 28PICT carburettors were used on 1200cc and the first 1300cc engines. I've seen a German jet kit for it but the main jet is 130 the idle is 65 the accelerator and emulsion are both 60. such as, how do you know what mixture you are setting, and if you are running the car too lean and hot, or way too rich? There is an pilot (idle) jet on all carburetors too - these are normally left at 55 for most carburetors (28, 30, H30/31 and 34 series), on any engine size (since it's only feeding the engine at small throttle settings anyway). This is prone to getting blocked up and causing you idle issues. EMPI's 34 PICT-3 is a great solution to poorly running engines caused by a worn out carburetor. Useful experiment anyway. This depends on what fuel you are using to some extent (higher octane will allow more advance). Air correction jets are harder to find. What you are mainly looking for is the condition of the carburetor. The air correction jet has to be the right size for the same reason. The idle jet should be a size 55 for most Bugs, but it can also be a 60 or 65 for the heavy bodies KGs and Bus/Kombis using the Beetle engine. And the second issue is the presence of Ethanol (alcohol) in gasolines. If you live at altitudes above 5000 feet, you also have to consider that, as high altitude results in the engine running rich (less oxygen in the air but the same fuel flow through the carburetor). If the color of the deposit is tan or brown, you are running too lean and the main jet size should be increased. up enough to allow the linkage to clear the alternator . Running a 130 main jet. I've never had to do this so don't even know if it would work well. Assuming a vacuum distributor, the 34PICT/3 carburetor is usually jetted with a X127.5 main jet, and 100Z -120Z air correction jet. Jetting was tweaked over the years for various carbs and territories. Ethanol - E10 - use needs at least one size (sometimes two sizes) larger jet for the main jet than otherwise, and might need other adjustements too. The /4 version was used in California and had additional features to reduce emissions. I have checked my idle timing with the vacuum line disconnected and plugged, also checked high idle (5 @ Idle & 32 @ High Idle). Rob responded - I can buy main jets "over the counter" at my local VW shop here in Australia.