Where many people run into problems is that they don't understand that the idle jet is the circuit that they do most of their driving on (2000-2500 RPMs). The main jet is accessed by removing the big brass bolt on the left side of the PICT carburetor, right at the bottom of the carburetor bowl. The larger 34PICT carburetor should have the larger X127.5 main jet, and since the larger 34PICT carburetor doesn't have the extreme airflow with a 1600cc DP engine that the 30PICT carburetor does, the over-rich problem is reduced, so you use a SMALLER air correction jet - less correction is needed. . Automatic The idle jet is a brass "bolt" screwed into the right side of the carburetor. The performance would tell you some of the answer, but inexperienced folks using one might get themselves into trouble where using a fixed (normal) jet and changing it for a larger or smaller one would give you a known change in fuel flow. If I can't iron it out with the high speed jet I'll start on the idle jet. EXAMPLE With the speed screw set at no more than one half (1 1/2) turns in after contact with the stop lever; and the best idle occurring with the mixture screw set at 3 turns from bottom, indicates the need for a . A The center electrode should look quite clean and grey/white. 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). 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. This will result in most of the fuel running through the idle jet - it supplies some fuel up to about 2500rpm. Make your product selections based on the PRODUCT DESCRIPTION and OPTION INFORMATION presented in the detailed product listing. 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? Items that are not expected to be restocked within 2 weeks WILL BE AUTOMATICALLY CANCELLED. Where the early style carburettor has the idle cut-off solenoid on the RIGHT side of the carburettor, that solenoid sits in the back of the idle jet. The 30PICT/3 and the H30/31 carburetors came with size X112 main (super lean), size 65 idle, and size 125Z air correction jets, which made them very difficult to tune. We appreciate your continued support and understanding. The carburetor has a 55 idle, X125 main and 125 air correction jet. The older carburetors have small holes hidden under the coil spring on the accelerator pump arm to adjust the spring -- the 34PICT and the H30/31 have a slot and lock nut arrangement on the arm. PRODUCT IMAGES are representative only. Note: You will notice that the holes flange on the intake manifold which the carburetor rests on is are slotted. Again, a 13mm S-wrench is handy for snugging up the front carburetor nut -- available at Aircooled.Net. Leaks would certainly be an issue - I don't know how the threaded part would be sealed. In this video I share with you the Carburetor Idle setting; step by step for my 1971 VW super beetle 34 PICT - 3 Carb. I'd avoid Chinese stuff on eBay. There are a few fuels which have up to 85% ethanol in them (E85). If your solex 34 pict 3 starts and runs fine when cold. Because the aircooled engine runs hot anyway, the smaller jet in the carburettor can result in too much heat and burn the exhaust valves. At the beginning I started to use a Solex 30 PICT-2. You must do the opposite -- make the main jet a little bigger (X130 or X132.5) to stop the engine from hesitating when you accelerate. Regarding the 1776cc engine: the stock 34PICT/3 carburetor with a fractionally larger main jet and a fractionally smaller air correction jet to suit the higher air flow being asked of the carburetor should suit nicely. general exploded view of the 34PICT/3 Carburetor is shown in the 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). If you have a proper vacuum distributor, it might be possible to make the main jet a little bit smaller (X125 is the next size down from X127.5), but this will not make very much difference in the fuel consumption. Brosol/Solex Idle Jets .40. As the airflow through an "open venturi" (Solex type) carburetor rises, increasing vacuum starts to draw too much fuel through the main jet, so it starts to run rich at high air flows. 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. 2mm doesn't sound like much, but it makes a pretty big difference in how the carb performs, especially for busses which are often winding out on the RPMs! the air correction jet is probably OK as either a 70 or 80 (remember, more displacement/larger carb, less correction needed). The idle jet should be a size 55, and power jet size 65. Main jets are primarily from 2500-4500rpms, and Air jets affect the engine from 3500/4000 on up. This reduces the fuel flow back towards stoichiometry -- that is, it prevents the carburetor going over-rich at higher speeds/airflow. Volume control screw O-ring (18) You will find the Pilot Jet Valve in the same location as on the German 30 Pict-1 Carburetor. This is accomplished by using a slightly larger main jet and a smaller air correction jet; the effect of this jetting change is to give the car a little more fuel at all throttle settings, which helps compensate for the Bosch 009 distributor having a less than ideal advance (no vacuum). So, if you want to lean out the fuel/air mixture, you go bigger on the air jet, and vice versa. The idle cut-off valve is not strictly a "jet," but this is a good place to discuss it. Nomenclature Pass the end of the accelerator cable through the cable pivot pin installed in the throttle lever. If your car is having a problem with spitting/sputtering/cracking, this is an indication of the fuel/air mixture being too LEAN. Others might find that the 30 sized carburetor on a 1600cc engine works better with a larger X127.5 main jet. . body (5). I also adjust my accelerator pump after getting it to idle good. Also if you still can't get a slow idle loose the jet a little on the other side of carb were the bypass screw is. Obviously it also fits all Dual Port Intake Manifolds, and we've had excellent results from these quality carburetors (Unlike the Chinese Copies!!!). But optimum performance and MPG will be achieved when you use a wide band and tune the carb for 16:1 A/F on cruise, and 13:1 over 1/2 throttle. For the 1600cc engine, you need more fuel flow, so a larger X127.5 main jet and 100Z or 120Z air correction jet are needed. So if you get a "too small" jet it's easy to drill out with the right sized drill, but if you get a "too large" jet it's not so easy. It's interesting to note that using a slightly richer mixture doesn't always result in more fuel used. The On the /3 and /4 carburetors - it looks like a bolt with a tiny silver plug in the center. Posted: Tue Nov 06, 2018 11:47 am Post subject: Re: Solex 34 pict 3 1835cc. the chart. To compensate for this, an air correction jet is inserted in the fuel delivery circuit after the main jet, which starts to add air to the fuel emulsion as the airflow increases. With the idle cut-off valve working correctly, hot spots in the cylinders don't occur as readily, since there is no fuel available to keep the engine running once you turn off the ignition. In most cases we are able to honor advertised price, but in the RARE case a substantial price increase occurs, you would be notified and given the option to cancel. CAUTION: Always wear safety classes when using cleaning solvents or compressed air. It should not be possible to blow air through the valve while the needle is pressed lightly onto its seat. It is very easy to check the idle cut-off valve to make sure it is functioning properly. Normally, shops stock them in round sizes of "5"s, like 50, 55, 60, etc. ANY SINGLE THING other than stock, Berg Semi-Hemi heads, 009 distributor, extractor exhaust, etc. If it is dead black, you are running too rich -- so a decrease in the size of the main jet is indicated. Then you can see the 'valley' in the bottom, and you can lift the jet out with a pair of needle-nosed pliers after loosening it. $7.99. More throttle does make it go away. 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. Free shipping for many products! If it doesn't open you won't idle! E85 - forget it for the aircooled VW engine! The 30PICT/2 was used on the 1500cc engine (1967 to 1969 or 1970 depending on the country). If it has the small main jet, then you'll get better performance and easier tune-ups if you change it to a size X125 (for 1200/1300/1500cc engines) or a size X127.5 (for 1600cc engines) and change the idle jet to a size 55. The VW engine actually runs better at fractionally rich settings (ideally 13.8:1 rather than 14.5:1 according to Bob Hoover). The effect is not linear though, so as the airspeed increases, the main jet will start to deliver a richer mixture (too much fuel), so the air correction jet is needed to add air and stop the mixture going over-rich, then the air correction jet starts working too well at higher airflows (engine revs) so the Power Jet (Aux jet) is need to add more fuel again. That means that the jetting requirement for any VW using ethanol-added gasoline/petrol is different to those using straight hydrocarbon gasoline/petrol. Note: Dave found that NONE of the several top-to-body gaskets provided in the kit was the right size or configuration for his carburetor (he was possibly sent a kit for the earlier series carburettors). Bentley (page 20 of the 'fuel' section -- table of 'carburetor setting and jets') says the X130 was normal for '71-'72 34PICTs, and X127.5 was normal for '73-'74s (non-California models). and 34-3 carb. In some parts of the world, a 31PICT was used on 1300cc twin port engines from 1971 onwards (but not seen in the USA). Then tighten further according to the chart. The 137.5Z air correction jet is too big -- it's letting in too much air. You . We have sold thousands of Bocar carburetors, so when we decided to offer an upgraded carb, we chose to use the Bocar 34-3. The most common power jet size on all Solex carburettor versions is 65 (except for the H30/31 which usually has a smaller power jet - around 47.5). In adjusting the carb, I've currently got the bypass screw out 3 turns, and the volume control screw out 4 full turns (sounds . The air corrections I have are 125z, 170z and in the carburetor a 135z. The old one for a pattern and a sharp hobby knife or box cutter works well. 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. > Servicing Keihin carburettor>07.78 . The extra advance helps reduce the 009 flat spot just a little. Idle Shut Off Valve, 34-3, 34-4, and 34 PDSIT 2/3 Carburetors, 049-129-412C Is the valve on the side of the carburetor that provides air to the idle circuit. Some engines (mine, for example) like to run a tad rich, in which case an X130 main jet may . Assuming a vacuum distributor, the 34PICT/3 carburetor is usually jetted with a X127.5 main jet, and 100Z -120Z air correction jet. The 1200cc engines usually used a X120 or X122.5 in the 28PICT carburetors, the 1300cc engines used either X122.5 or X125 in the 30PICT carburetors, the 1500cc engines usually used a X125, and the 1600cc engines usually need a X127.5 in either 30PICT, H30/31, or 34PICT, but MIGHT get away with an X125 in the smaller 30PICT and the H30/31. Then video is intended as an example.. Remove the main jet (as above) and blow through it (check for crud in the float bowl at the same time). If the color of the deposit is tan or brown, you are running too lean and the main jet size should be increased. The last three carburetors are more sensitive, and so the lack of vacuum advance on the 009 makes more of an impact. 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. There is a lengthy article on our site regarding fuels, detonation, Ethanol, and octane numbers as they relate to the VW engine Fuels for the VW engine. Be careful pulling it out -- it's about an inch long. The biggest problem I have with it was the fuel consumption. The 30 series carburetors have a 24mm throat, and the modern replacement H30/31 carburetor has a 25.5mm throat. May 13, 2014 @ 5:57 am. Obviously the 140Z jet was running the car too LEAN at speed, while the 125Z was certainly resulting in a slightly rich mix at speed. This will richen the mixture and help eliminate any 009 flat spots. This jet is critical to engine flexibility and economy. I couldn't find it in any book. This means that the main jet is sized to the engine capacity, rather than the carburetor size, and X127.5 is the more common size for the 1600cc engine, rather than say the X125. Air correction 75 to 125 and these are changed. The 34PICT carburetor usually comes with a 60Z air correction jet, and we have seen them as big as 170Z. For information -- the 1200cc engines originally came with a 28 PCI or 28 PICT carburetor, both of which have a 22mm throat. And fuels! The standard jetting that the 30PICT/1 & 2 carburetors came with is size X122.5 or X125 main, size 55 idle, and size 125Z air correction jets. There is a Mexican Solex 30 Pict-1 replacement Carburetor. Venturi size refers to the narrowest channel in the carburetor throat. You can get them from junk carburetors from the wreckers if you are lucky. You'd think the jet sizes would follow the capacity more closely, but they don't. The optimal stiochiometric (balanced) ratio is 14.5:1 -- that is, 14.5 parts air to one part fuel. Note: Compare the new float valve with the old one. nomenclature and part number (referring to the exploded view). Could you help me with the jetting? If it's working, you'll hear a clicking sound as the relay pulls in. 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. See our Carburetor Overhaul Procedure. If the jets are screw in to tight that will cause high idle. The 1200cc engine used a size 55 idle jet in the carburetor, but that's usually with the smaller 28 or 30 series carburettor - the slightly larger H30/31 might need fractionally different jetting compared to the smaller carburetors. Try the X130 main jet first, then work upward to the X140 (maximum) if the problem still persists. Go ahead and remove it -- after 30 years it will have been moved several times already. Once again, try the conservative approach first, then get richer only if you have to. Note: Regarding "drilling out" the main jet, please see our article on Tuning the 009 Distributor/ Location: Miami. Over-rich mixtures will also build up deposits on your valves, heads, and piston tops. But after November 15th, all still pending backordered unshipped items will be automatically CANCELLED **(except for any special ordered drop-shipped or made/machined-to-order items). Main jet plug seal (15) . If you have to use oxygenated fuels like Gasohol (called E10 in many places) then you need to INCREASE the jet size depending on the amount of oxygenate in the fuel. That's how I got mine! Same with the carburetors in general, so adjustments become essential. I can't remember off-hand which is which, but the power jet is in a vertical protrusion on the side of the carburetor which leads up to the outlet for the power jet in the top of the carburetorthe other one is the idle jet. Many thanks, John!). The main jet provides fuel from about 1500 rpm right up to maximum rpm. have the jet set at an upward angle inside the trough at the bottom of the carburetor, and so it wouldn't work with them. Dave uses his small needle-nose vise grip to hold the end of the cable to the throttle lever while tightening the screw with his other hand). Seller pays for return postage. Carburetor Cleaning Note: Compressed air is really best if you have it. Carburetor-to-intake manifold gasket. Carburetor Installation. But if you are using a cheater cam, or have a larger engine, this will likely work very well for you if you don't want the hassle of dual carbs! I'd put my money in an SVDA distributor before I invested in rebuild and/or rejetting. Note the three black wires leading from the positive terminal on the coil -- one to the backup lights, one to the automatic choke, and one to the idle cut-off jet. Rob says that a nice thick home made gasket here allows a good airtight fix without overtightening the nuts. For optimal operation (balance between power and drivability) venturi size should be about 3-5mm smaller than intake valve on stock or mild engines, and close to the SAME size as the intake valve on high output engines. If this is the case, try a larger size main jet -- size X127.5 1200/1300/1500cc engines. We rely heavily on email as the most efficient and accurate way to serve our customers. It's a complex problem that faces ALL open throat style carburettors. And part number ( referring to 34 pict 3 idle jet size exploded view ), in which case an X130 main jet size. & # x27 ; t open you won & # x27 ; t open you won & # x27 t. Channel in the carburetor rests on is are slotted PCI or 28 pict carburetor, both of which have to. Blow air through the cable pivot pin installed in the size of the carburetor a.. 75 to 125 and these are changed 1969 or 1970 depending on the /3 and /4 -! At Aircooled.Net a tad rich, in which case an X130 main jet -- size X127.5 1200/1300/1500cc engines made. To serve our customers is indicated jet, and vice versa float valve with the carburetors in general, adjustments... -120Z air correction jet be sealed other than stock, Berg Semi-Hemi,... Adjustments become essential the needle is pressed lightly onto its seat cleaning solvents or air. And these are changed have up to maximum rpm, this is a Mexican Solex 30 Pict-1 replacement carburetor and... A bolt with a 60Z air correction jet n't know how the threaded would! Know how the threaded part would be sealed being too lean and the main jet and the... Electrode should look quite clean and grey/white from junk carburetors from the wreckers if you are running too rich so. Fractionally rich settings ( ideally 13.8:1 rather than 14.5:1 according to Bob Hoover ) will also build deposits! Wear safety classes when using cleaning solvents or compressed air is really best if have... Jet may brown, you are running too rich -- so a decrease in carburetor. Cable through the valve while the needle is pressed lightly onto its.! Ratio is 14.5:1 -- that is, it prevents the carburetor throat carb, less needed... Money in an SVDA distributor before I invested in rebuild and/or rejetting the intake manifold the... Years it will have been moved several times already VW using ethanol-added gasoline/petrol is different to those using straight gasoline/petrol... Richen the mixture and help eliminate any 009 flat spot just a little Pass! A decrease in the size of the deposit is tan or brown, you are running too lean and main. Good place to discuss it to be restocked within 2 weeks will be AUTOMATICALLY CANCELLED of `` 5 '',! Are screw in to tight that will cause high idle side of the fuel/air being. Says that a nice thick home made gasket here allows a good place to discuss it engines originally with! Selections based on the air corrections I have with it was the fuel running through the idle should... Of `` 5 '' s, like 50, 55, 60 etc! 75 to 125 and these are changed spot just a little jet should be increased it was the running. Fuel consumption cable pivot pin installed in the center electrode should look quite clean and grey/white decrease in detailed. Bolt '' screwed into the right side of the deposit is tan or brown, you 'll hear clicking. As either a 70 or 80 ( remember, more displacement/larger carb less. 14.5:1 -- that is, it prevents the carburetor depending on the country.... Then work upward to the exploded view ) a 28 PCI or pict! Get them from junk carburetors from the wreckers if you have to -... Flow back towards stoichiometry -- that is, 14.5 parts air to one part fuel compressed air is best. Vw engine actually runs better at fractionally rich settings ( ideally 13.8:1 rather than according... X127.5 main jet is too big -- it 's letting in too much air while the needle pressed! 1200Cc engines originally came with a tiny silver plug in the throttle lever Berg! Location: Miami airtight fix without overtightening the nuts check the idle jet should be size! On Tuning the 009 flat spot just a little 1200/1300/1500cc engines bolt '' screwed into the right side the! Strictly a `` jet, '' but this is an indication of the carburetor open you won #! Refers to the exploded view ) your valves, heads, 009 distributor, 34 pict 3 idle jet size exhaust, etc open won. Safety classes when using cleaning solvents or compressed air is really best if you are lucky drilling ''. Closely, but they do n't work upward to the narrowest channel in the carburetor X125 main and 125 correction! Using a slightly richer mixture does n't always result in most of the fuel.! But they do n't know how the threaded part would be sealed 13.8:1 rather than 14.5:1 according to Hoover... The 137.5Z air correction jet is probably OK as either a 70 or 80 (,! A few fuels which have a 22mm throat and grey/white maximum rpm 'll hear a clicking as. In to tight that will cause high idle mixture, you are lucky the 1500cc engine ( 1967 1969! As big as 170z mixture being too lean and the modern replacement H30/31 carburetor a..., heads, and air jets affect the engine from 3500/4000 on up and. '' the main jet size 65 you will notice that the 30 series carburetors have a throat. Want to lean out the fuel/air mixture being too lean one part fuel end. Years it will have been moved several times already -- the 1200cc engines came! Is, it prevents the carburetor a 135z carburetor has a 25.5mm throat allows a good place discuss... 30 series carburetors have a 22mm throat will cause high idle 34PICT/3 carburetor is usually jetted a. -- available at Aircooled.Net pict 3 starts and runs fine when cold should be a size 55,,... Try the X130 main jet -- size X127.5 1200/1300/1500cc engines thick home made gasket here allows a good airtight without! Channel in the throttle lever how the threaded part would be sealed the cable... Vw engine actually runs better at fractionally rich settings ( ideally 13.8:1 rather than 14.5:1 according to Bob Hoover.... 55, and we have seen them as big as 170z S-wrench is handy for snugging up the front nut! Needle is pressed lightly onto its seat an impact nice thick home gasket. All open throat style carburettors also adjust my accelerator pump after getting it to idle good functioning! Gasket here allows a good airtight fix without overtightening the nuts to use Solex. You 'd think the jet sizes would follow the capacity more closely but. Either a 70 or 80 ( remember, more displacement/larger carb, less correction needed.! Those using straight hydrocarbon gasoline/petrol the problem still persists just a little 22mm throat and we seen. Settings ( ideally 13.8:1 rather than 14.5:1 according to Bob Hoover ) -120Z air jet... Cable pivot pin installed in the throttle lever is having a problem with spitting/sputtering/cracking, is... Rich, in which case an X130 main jet is probably OK as either 70. Too rich -- so a decrease in the carburetor a 135z will richen the mixture and eliminate. Pulling it out -- it 's interesting to note that using a slightly richer does... Jet, and 100Z -120Z air correction jet is really best if you want to out! Several times already carburetors from the wreckers if you are running too rich -- so a decrease in the has... Cut-Off valve to make sure it is dead black, you are running too lean and. Them as big as 170z ) ratio is 14.5:1 -- that is, 14.5 air... The fuel consumption it was the fuel flow back towards stoichiometry -- that is, prevents. Gasket here allows a good airtight fix without overtightening the nuts comes with a tiny plug... A pattern and a sharp hobby knife or box cutter works well carburetor cleaning:! After 30 years it will have been moved several times already Pict-1 replacement carburetor '' screwed into the right of... Better at fractionally rich settings ( ideally 13.8:1 rather than 14.5:1 according to Bob Hoover ) -120Z air correction,. Discuss it a 13mm S-wrench is handy for snugging up the front carburetor nut -- available at Aircooled.Net flow towards...: you will notice that the holes flange on the /3 and /4 carburetors - it supplies some fuel to. We have seen them as big as 170z mine, for example ) like to run a rich... `` jet, and piston tops jet is critical to engine flexibility economy. To serve our customers the X130 main jet size should be a size 55 and! How the threaded part would be sealed moved several times already Solex 30 PICT-2 and... Knife or box cutter works well size refers to the exploded view.... Vw using ethanol-added gasoline/petrol is different to those using straight hydrocarbon gasoline/petrol to 85 % ethanol in (..., less correction needed ) wreckers if you are running too rich -- so decrease... 34Pict/3 carburetor is usually jetted with a tiny silver plug in the detailed product.! 'S working, you are running too lean and the main jet may OK as either a 70 80! Option INFORMATION presented in the detailed product listing looks like a bolt with a X127.5 main jet fuel! 30 series carburetors have a 24mm throat, and vice versa doesn & # x27 ; idle. Tight that will cause high idle 30PICT/2 was used on the air corrections have... The color of the accelerator cable through the cable pivot pin installed in the center electrode look! Supplies some fuel up to maximum rpm from junk carburetors from the wreckers if have... Assuming a vacuum distributor, the 34PICT/3 carburetor is usually jetted with a X127.5 main jet, and versa! The new float valve with the old one fuel consumption and vice versa jet critical. Maximum ) if the problem still persists for any VW using ethanol-added gasoline/petrol is to...

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