Ignition timing is set per OEM specs at 10 degrees BTDC at idle. Share your knowledge of this product with other customers. On the carburetor cover, there are two small holes that are used to take in extra air, in addition to the air that is sucked in through the velocity stacks. and if I screw all in, the engine will dies. Shown below is an exploded view of the WEBER 45 DCOE carburettor. The 50 refers to the. It just is what it is. Mine on a 1600 are 130 mains, and 55 idles. and the rest is history. Performance Brands / Weber Carbs and TWM / Borla EFi Induction / V8 Ford and Chevy 48 IDA and IDF Kits. We list the stock Pilot Jet Sizes that came with the bikes below, you can use this list as a reference if you are trying to increase/decrease or keep the pilot jet size stock. By Rob Robinette. I had ordered an idle jet to replace the. We offer a complete selection of perfomance VW Weber carburetor kits. It regularly happens that the nozzle of the Solex carburetor is clogging, especially when there is dirt in the fuel tank. Idle Jets and tuning the idle circuit: Very Simply. Your order may be eligible for Ship to Home, and shipping is free on all online orders of $35. The Motorcraft/Holly carbs were built under licence from Weber and almost identical to the carbs found on Vegas (the 2bbl Vegas). What is happening doesn't make sense to me. If you try to use three primary carburetors, it will be. Needle & Seat, For Epc 32/36, Weber DGV, DFV, 1. We were successful with one thing today the new jets stopped the dieseling. FREE Shipping. 045 Weber IDA. I will be happy to exchange emissions Weber tuning data with anyone. A 50 Idle jet is a. Imperial Hwy Brea, CA 92821 1-877-405-4345. Changed primary idle jet down to a 45 from a 60. 9 Using tag wire, clean the idle circuit fuel pick-up that is located in the center leg. Discover MINI SAVs, 4 door, & 2 door cars. The PMO carburetor uses standard Weber main and air jets found in the Weber IDF, DCOE and 48 IDA. Right now I have a X127. Look no further for versatility, wide adaptability, easy installation, low initial cost, trouble-free maintenance, excellent drivability, increased fuel economy and improved performance. _____ It's just advice, do whatever you want with it! Please do NOT send me Private Messages through the Samba PM System (I will not see them). 40 Secondary Main Jet -. Instructions that are critical to the vehicle as well as the installation are provided. If you change one idle mixture needle, you must change the other idle mixture needle by the same amount. Walt Disney World History “WALT DISNEY WORLD is a tribute to the philosophy and life of Walter Elias Disney and to the talents, the dedication and the loyalty of the entire Disney organization that made Walt Disney's dream come true. By "jet sizes" I am referring to all of them (main, idle, air correction, emulsion), and by "locations" I am referring to which sizes go on which side (primary and secondary). Readjust the idle RPM adjustment for the idle speed that you prefer. 5 full turns, then lower the idle while its running. The engine starts and runs but revs up and down in speed: this may indicate restricted fuel flow to the carburetor, or it may indicate a partial restriction of a jet or passageway within the carburetor. Re: Weber 38 DGAS Jetting So I did as Sir Grips said and put some 145 mains and 210 airs in, and a new idle jet. We also stock a large selection of Vintage Marine Carburetors. The Weber 34 DGEC supposedly arrives 'pre-adjusted. 2000cc 50/55. In the DCNF and IDF, the idle air bleed is fixed. The Pilot jet only controls the air/fuel mixture at idle and low, off idle, throttle openings. Weber IDF Jetting Chart. Idle jet holders in order of mixture Weak 5-10-9-4-1-3-6-7-2-8 Rich ***Only to be used with pre-emission variation DHLA’S*** DHLA40 – no letter DHLA40 C DHLA40 E DHLA40 H turbo DHLA45 – all types DHLA48 – all types The figures in the below chart refer to the quantity and size of the air holes in the respective jet holder. possible, however, unless all of the available adjustments have really been optimized on each carburettor type and on the same engine. Upon take off there is also an occasional stumble. Most performance-oriented Holley carbs have jets on both the primary and secondary sides. At idling speed the idle mixture adjustment can be set to control the volume of mixed or emulsified fuel and air provided by the idle jet assembly and if a correct jet has been selected the setting of the. “Simple Rules for Calibration” If your mixture screw is out more than one turn like 11/2 turns then your idle jet is too lean, go up one half size on the Idle jet. The idle PROGRESSION jet can be richened up also, that is the one on the side of the carb, near the top of the primary. 2 liter engines came with a rather lowsy carter bbd carburetor which of goes out fo adjustment. A 50 Idle jet is a. Whether competing for a prize or for the simple joy of it, this is a pastime many people dedicate their time and energy to for the fun of it. 010 Not Serviced *Calibrated Parts Require 3 Digits To Complete Part Numbers. I will be happy to exchange emissions Weber tuning data with anyone. I pulled the top off the Weber to make sure check ball was free in the accelerator pump bolt, it was. Fortunately, both carburettors are. Like clockwork—just weirder and full of flammable liquid. RHD Throttle Quadrant Assembly. The initial off idle is bogged a bit. Carburetor Center. Toll Free 1-800-456-9645 Toyota Corolla Redline Weber DCOE dual carb and manifold kit Wake your 2tc 3tc Corolla engine right up Serious bolt on horse power Not for the faint of heart Product is the same as picture!. Do 8 Stack EFI or Weber Carbs Run Good On The Street? The answer isn't so simple, but overall the answer is no, not as well as you think, or as they advertise them to be. On the other carburetors, the idle jet does it all. Hi everyone, I recently installed a DGEV 32/26 Weber Carb on my 1983 Nissan 720. You're ready to chew gum and kick butt, and you've run out of gum. Approximately 60% of the time when you are driving, the idle jets will be what is primarily supplying fuel to the car. On a engine with a performance cam(low vacuum) this will benefit idle smoothness regardless of the lack of adjustment. Hello jeff, I'm running a 1411 , 750 edelbrock carb on a 427 cid SBC. 25 the size of the throttle body. Most of these Webers have a 50, 55, or 60 idle jet. When you blip the carb there is an occasional stumble and 2. Appletree Automotive offers a complete line of VW CARBURETION WEBER REPLACEMENT PARTS. Turning to European data where Lancia is joined to Chrysler, even here the loss is heavy and above 26%. Hot Idle Compensator (fig. The carburetor has multiple adjustments for different throttle positions; 0-1/4 Pilot jet 1/8-1/2 Throttle cutaway -3/4 Jet needle (clip) -3/4 Needle jet -Full Main jet -Full Air adjustment screw -full Power jet (optional) Starter Circuit. weber 44 idf sizes air correction 1 75 emulsion tube main jet 1 35 pump jet ole jet venturi note: 2mm e i n val factory weber 48 idf sizes air correction emulsion tube main jet 1 so pump jet ole jet venturi 40 mm note: 2mm e i n val facto ry weber 34 ict sizes air correction emulsion tube f_78 main jet pump jet ole jet single carb 160 1 45 (d). Your Dunebuggy or VW Beetle will be up and running fast when you get your parts from AppletreeAutomotive. This Jetting Chart provides a base line starting point provided by CB Performance. You can then switch between the drawing and this page here as the numbers in the. 001" size increase in jet size is equivalent to a 1% increase in WOT fuel mixture. Too lean will require a larger than needed idle jet to compensate. Have a Question? Call Me! A Live Person Will Pick Up the Phone and Be Ready to Talk Carburetors. Adjusting the Motorcraft 2 barrel carburetor to the proper settings will provide you with more performance and better fuel mileage. 37 Primary Main - 1. If setting Lean Best Idle requires the mixture screw to be turned out 1-1/2 turns or more, the idle jet is too lean. Hello, Just tried out my Carbtune and colortune gear. Weber 40IDA3C, 40 IDA 3-C etc not sure if the layout is the same on 46's. 045 Idle Jet 045 74405. SKU: 43-5050-7. The primary idle jet is inside of the idle cutoff solenoid, which is at the bottom of the photo off the passenger side of the carb. This jetting example submitted by Frans Deguara, 31 October, 2011. For example, a 40 IDF would need a 40 x 1. Rebuilding and tuning an Edelbrock carburetor. Idle mixture needles are found on the primary metering blocks. FREE Shipping. Brief Pictorial - Idle Jet Cleaning on Weber 40 IDA 3C Suspected idle jets and had some assurances from others on the board that was likely the case. 4 sizes Idle Jets @ 4 each. Then ordered a jet kit from your company - order number 3059. The car How to change Idle jets in a Weber DGV Shows you how to change the Idle jets in a Weber DGV carburetor. Changed primary idle jet down to a 45 from a 60. 50-60 is the range of sizes used by the 1. REDLINE 1225 W. The 009 distributor can't load sense (see our articleTiming Vacuum Distributore. The idle jets are specific to the PMO and IDF. WEBER CARBS, Carburettors, Jets, Emulsion tubes, Conversion Kits, Air Filters, Linkages, Rebuild Kits, carbparts. Then fiddle with the mixture crews, then idle jet and idle air-correction (the F# on the idle jet). Idle mixture needles are found on the primary metering blocks. 5(1) 125/130: F50/F6: 180/180: 55/50: 55: 40(1) 200 (2) Ford Europe: 32/36 DGV. 9 Using tag wire, clean the idle circuit fuel pick-up that is located in the center leg. The dyno chart below shows the same comparison as above with another test added. 0: 115/105: F50/F50: 200/200: 55/50: 50: 40(1) 200 (2) Ford Europe: 32 DGV 7A 18870. Idle jets allow you to dial in your carburetor for your altitude, engine size or the quality of fuel that you have available. Brosol/Solex Idle Jets. 1,3 79 4l 4g13. FREE Shipping. Most relevant holley 1920 websites. We do not recommend drilling out jets as the result can be a hole that is not perpendicular, an out of round hole, burr in hole and more. 3 pair Idle Jets. Gasket For Idle Jet Holder Idle Jet Bushing Spring Washer Idle Mixture Adjusting Screw Spring For Idle Mixture Screw Shaft Seal Throttle Control Lever. An air leak can also cause a high idle (either loose carburetor parts, a bad gasket, or a leaking/cracked hose). Constant jet movement on the wire can internally erode the component, creating the same effect as drilling the part. If the pressure drop is less than the jet’s maximum rated capacity, the jet flows proportionately less. The drawing will open in a new window. 050 Secondary Idle Jet - 1. In the IDF and DCNF, the idle air is "fixed" via the air bleed, and that's why they have idle jets available in increments of "2. After synchronizing multiple Carburetors, reconfirm steps b. It is quite tuneable and extremely reliable, making it a very popular carb to retro-fit on a great many engines, including those found in out LBCs. Since the beginning of the year, Lancia has sold 31,895 cars in Italy in 8 months, with a drop of around 28%. Got the spec from kawasaki today, and sure enough, it was 2mm below spec. Main jet replacement should be reserved until after the slow idle jet is replaced and mixture is tuned unless a lean condition is apparent during full throttle. Another common problem with Weber carburetors is that they sometimes spit out the top of the velocity stacks. As with the emulsion tube, the idle jet is chosen based upon the. The engine is a 1994. The Holley marine carburetor can be either a 2 or 4-barrel carburetor, depending on your motor, and will have the same number of idle mixture adjustment screws. Idle mixture needles are found on the primary metering blocks. 25 = 50 idle jet. WMA-7-1A Mercury 1989-1997 Top Carburetor 30 JET 40 HP 4 Cylinder. If not, try a smaller idle jet anyway. * Not Serviced 55530. what IT had) There are gradients as to jet size reduction correlation with altitude above sea level. The brass main jets are easy to drill so you can get by with one of these inexpensive drill bit sets. 6 to arrive at your rough idle jet size, but what I've seen is that 50 to 55 is mainstream for about any 40 or 44 IDF. 5 aux venturi, F16 emulsion tubes, 145 main jets, 155 air correctors, 55F8 idle jets, 45 pump jet, 40 pump spill, 200 needle valve. The Weber carburetor has three basic circuits: the idle circuit, the accelerator pump circuit, and the main circuit. old engines might be a little less. Then my engine idle. For example the Pontiac will want a significantly larger idle jet (pressed-in) than the Chevrolet. weber dgv dcoe idf ida idle jet enrichment drill kit : $12. I pulled the top off the Weber to make sure check ball was free in the accelerator pump bolt, it was. The company was established as Fabbrica Italiana Carburatori Weber in 1923 when Edoardo Weber (1889-1945) produced carburetors as part of a conversion kit for Fiats. Later in the life of that vehicle, at around 150,000 miles, I changed the valve cover gasket and found 2 of the jet valve rocker castings broken off and laying on top of the head. Top quality universal carburettor pressure fuel pump suitable for all Weber carburettor installations. Note: This is only a rough estimator of carb sizing. Its the one in a channel heading down to the boottom of the carburettor. Weber IDF Idle Jets Please specify exact sizes when ordering Jets & Venturi (. Orifices are much larger on the idle circuits compared to the OEM carbs, so there is less chance of blocked idle circuits. Selection and tuning of Weber DCOE carburettors. CORRECTOR (jet holder, not the idle jet) and repeat. Hi Dan I have a Suzuki ts50 with a 70cc malorossi kit a delorotto phbg 21mm race carb fmf exhaust bike has no power until 4 k when you snap throttle it bogs down and dies out engine stops if you gradually feed power in gently it will rev up but soon as you put itb into gear to pull away it just dies down and stalls if you keep Revs up over 4 k. Idle Jet Identification (50F8) Figure 45. Jul 30, 2013 - Automotive & Motorcycle Performance Parts. Fix Idle and Stalling Problems on a Jeep Cj-7 or Wrangler Yj: Jeep Cj-7's and early wrangler YJ's with 4. WEBER CARBURETOR CONVERSION KIT INSTALLATION GUIDE PART # INS -WK551 Page 1 WEBER NA PART # WK551 AND WK551-38 THIS KIT IS FOR THE FOLLOWING APPLICATIONS: Jeep Models Originally equipped with the Carter 2BBL BBD Carburetor 1978 -1990. I changed the needle jet to 107 and the verdict was, too rich. Re: Weber 38 DGAS Jetting So I did as Sir Grips said and put some 145 mains and 210 airs in, and a new idle jet. How To Properly Adjust The Idle Mixture On Holley Carburetors By Jon Norton June 04, 2012 A carburetor is a device that sits on top of an intake manifold and has one basic job: to properly mix air and fuel for delivery into an engine. BMW 2002 Jetting and Tuning - Weber 32/36 Carburetor Today we continue to mess around with the engine to get it to run great. A prefix is added to describe the fuel orifice diameter in 100ths of a millimeter. We stock Rochester, Holley, MerCarb, Weber, Carter, Solex and Zenith rebuilt marine carburetors. Genuine Weber calibrated parts. Luckily I found some CB Emulsion tubes on eBay that were better than the standard ones. Too lean will require a larger than needed idle jet to compensate. Ford built FEs from 1958 through 1976, in a wide variety of configurations. Increase the size of the idle air jet hole. Dellorto jetting - 2000 Here is the stock jetting chart from the Brooklands Alfa manual for a DHLA40: Choke tube - 32mm Main jet - 135 Emulsion tube - usually 11 Air Corrector - 200 Idle jet - 50 Pump jet - 33 Choke jet - 70. A 44 IDF would need a 55 idle jet, and a 48 IDF would need a 60 idle jet. Hello, Just tried out my Carbtune and colortune gear. Idle Jet Pump Jet Pump Bleed Needle Valve Float Level * Derivation; DGV & derivitives: 28/30 DGV 14A 22550. We have the best Carburetor Linkage - Service Parts for the right price. 180 on secondary. Two idle jets are required per carburetor (one for MCHH). If you adjust the idle (mixture) screws and balance that way, you are just adjusting each choke for mixture (rich or lean). 0(1) 115/105: F50/F50: 200/200: 55/50: 50: 40(1) 200 (2) Ford Europe: 32 DGV 7A 18870. It runs too rich on the primary, then leans out when the secondary opens. The idle carburetor jets fit Weber IDF & DCNF and EMPI HPMX VW Carburetors. The Weber 45 DCOE is a popular choice for MGB owners looking to unleash a bit more power in the admittedly rather prosaic (but reliable) B-Series engine. Fortunately, both carburettors are. If you're at idle, the only thing that the vacuum effects is your pilot jet, because it provides the least resistance to the pull. I began jetting my weber 140/140 with 165/165 air cirrectors and 60/50 idle jets. The cap jet should then be adjusted to the suggested flow rate and must always flow greater than the compensator jet by 30 to 40 ml/min. The secret to understanding the critical nature of the carburetor set up and the advantages of a WEBER over other carburetors is the idle circuit. You can also see the 6 screws holding the top of the carb on. I'm trying to stick to one change at a time so thats the way I'll post them. Idle mixture needles are found on the primary metering blocks. On this chart the green line is the stock engine with stock SU carbs. What model Weber you have. If you need a new jet kit consider the following or try a repair kit. I'm trying to determine the stock jet sizes and locations for the factory Weber 28/30 DHTA carb. Test the fuel flow at the fuel filter and then at the Fuel Pump: If fuel flow is not adequate go to step 2C. Pump Bleed. In addition, if the fuel level in the float chamber is set too low, insufficient fuel will be drawn through the main jet. Net only carries ORIGINAL WEBER JETS FROM ITALY, we do not carry Chinese reproductions (whch do not flow properly!). 40 Secondary Main Jet -. 2 ZERO Pump By-pass valves. The best place to start is to increase the Primary Jet size. 5mm fuel hole. (there is one on the secondary also. As standard the fuel is fed to the inside of the filter, and the bowl to the carbs. On the carburetor cover, there are two small holes that are used to take in extra air, in addition to the air that is sucked in through the velocity stacks. Some carburetors have a slow speed fuel adjusting screw that regulates the fuel/air mixture in the lower rpm range. The speed screw is still about 3 turns in. You can also solder the ends closed and redrill them smaller if you are so inclined. 8 Remove carefully the idle restrictor cap, using the tag wire and carb spray clean the idle jet. Pump Jet 1300 101 Veloæ 40 DCOV2 4. 45F6 = Idle Jet. The main venturi is 1 7/32″ in diameter and the throttle bore is 1 7/16″. Make sure it is not more than 2. idle jet 45 F9 When you order you could buy a set that matches up for 32mm and hopefully you will be sound. Engine size Idle jet size. I guess you could also kind of say that their tuning strategy is analogous to dynamic jet/e-tube sizing or something. Your Location: Altitude, Temp. 289/302, 351, 429/460, Etc. The spitting is caused by the idle jets being too small. IDLE JET Both the DCOE and IDA carburetors have an idle jet assembly, which meters both fuel and air into the idle circuit. 94 per/jet Idle Jet (Small About 1/8in) Part # 74403. With the carburetor disassembled the first thing that caught our eye was the amount of varnish and debris in the float bowls. Before using this site please read the site disclaimer. venturis 3. 055 Part number example: 73801. Have a Question? Call Me! A Live Person Will Pick Up the Phone and Be Ready to Talk Carburetors. Weber IDA Idle Jets Please specify exact sizes when ordering Jets & Venturi (50 F10, 65 F10, 70 F10, 75 F10, or 80 F10) See our jetting chart to find the right size jet for your carbs. 60 For Weber IDF-DCNF/Empi HPMX Carburetors. The definitive Weber Guide to installing, calibrating and tuning Weber carburettors and listing thousands of Weber part numbers by carburettor type. 040 Idle Jet 040 74405. If you are experiencing any of these symptoms from your Weber carburetor or simply want to improve the quality and performance from your engine, these kits are for you. Parts are readily available worldwide. This jetting example submitted by Frans Deguara, 31 October, 2011. The most common problem I see with the engine is it's inability to idle. 175 Series Application Sizes available Series Application Sizes available 74401 DCD series 0. Can't speak to the quality (remember though, we're talking about EMPI), but I'd be willing to bet that jetting isn't even close to correct, even for the app they jetted it for _____ Travis 1972 Super Beetle. Make sure it is not more than 2. Displaying items 1 - 3 of 3: Sort: 20 Piece Carburetor Tuning Drill Bit Set Holley Rochester Carter Mikuni Walbro. Constant jet movement on the wire can internally erode the component, creating the same effect as drilling the part. Another common problem with Weber carburetors is that they sometimes spit out the top of the velocity stacks. Air bleeds often resemble a main jet only slightly smaller. Jets: venturis: 23/24 idle jet: 55/60 main jet: 135/137 Air corrector: 180/170 Emulsion tube: f20/f6 Aux venturis: 3. How to Adjust Motorcraft 2 Barrels by Carl Pruit. we have a race comming up at the family arena in St Charles on the 29 & 30th at the arena cross show, and have to run the winter blends. I always had good luck treating Microtechs like a digital carb if that makes much sense. A good deal of mystique surrounds Webers, specifically Weber jetting and tuning. 25 Main Jet. This article is an overview of how to remove and rebuild a carburetor. (d) = drilled † = Uses. The F number refers to air control, and the size number refers to fuel flow. , is the world's largest supplier of parts for the Corvair automobile. Weber IDF Idle Jets Please specify exact sizes when ordering Jets & Venturi (. So to go richer one size from a 55 idle jet, we would choose a 60. REDLINEWEBER. Gasket For Idle Jet Holder Idle Jet Bushing Spring Washer Idle Mixture Adjusting Screw Spring For Idle Mixture Screw Shaft Seal Throttle Control Lever. The Main Jet is only used at 3/4 to full throttle and has no effect on the idle or midrange mixture. Most performance-oriented Holley carbs have jets on both the primary and secondary sides. 055 Idle Jet 055 74405. 50-60 is the range of sizes used by the 1. 5mm fuel hole. Turning to European data where Lancia is joined to Chrysler, even here the loss is heavy and above 26%. 5(1) 125/130: F50/F6: 180/180: 55/50: 55: 40(1) 200 (2) Ford Europe: 32/36 DGV. The idle jet is a brass "bolt" screwed into the right side of the carburetor. Your order may be eligible for Ship to Home, and shipping is free on all online orders of $35. I blew them out with the compressor got 1 to spray carb clean thru it, the other seams plugged solid. I'm not sure how much power the 196 should have, but with the weber there is very little low end or high end power. The Motorcraft/Holly carbs were built under licence from Weber and almost identical to the carbs found on Vegas (the 2bbl Vegas). Remove the jets and insert a smaller/larger set based on the vehicles operating altitude. There is a chart on this carburetor, ('DGV' Weber site) and at the bottom of the page there is info as to what was originally in there, so one can make sensible adjustments from comparisons. Webers currently have 30 venturis, 125 mains, 55 idles, and 185 air corrections, F1 Emulsion tubes. 4 Pump Jets. we have a race comming up at the family arena in St Charles on the 29 & 30th at the arena cross show, and have to run the winter blends. weberperformance. I am assembling a set a of Weber 40 IDAs for my friend's 2. Primary idle jet, 45-50 at sea level, 40-45 @ 5k’. Jet storage is also important. CORRECTOR (jet holder, not the idle jet) and repeat. JET DRILL SET AND VICE £37. In the DCNF and IDF, the idle air bleed is fixed. Hey Mark, I was wondering if you could refersh my memory on the changes in jetting needed vs the alcohol content on the summer vs winter blends. Jet kits provide a selection of jet sizes to make it easy to add/reduce the amount of fuel/air mixture. The carburetor is new (not rebuilt). Re: Jetting a 40 DCOE for 1275 We've got the Yellow Sprite with the Weber that has given us yeoman service on a 948 plus I've got two Weber 40 DCOEs lying around with one goose-neck manifold. i just bought a re-jet/re-rod kit for the carb from napa and used this chart to help choose which rods/jets to use. Keep in mind that these specifications were written when gasoline was much different than it … Continued. Rebuilding and tuning an Edelbrock carburetor. You will receive tracking number. Hi Dan I have a Suzuki ts50 with a 70cc malorossi kit a delorotto phbg 21mm race carb fmf exhaust bike has no power until 4 k when you snap throttle it bogs down and dies out engine stops if you gradually feed power in gently it will rev up but soon as you put itb into gear to pull away it just dies down and stalls if you keep Revs up over 4 k. Now, adjust the screw about half way between the two positions, and you will often hear a very slight increase in engine RPM. Pump Jet 1300 101 Veloæ 40 DCOV2 4. Re: Weber 32/36: Fuel Pump Recommendations you could. What Im now curious about is what performance issues, if any, would this. * Not Serviced 55530. Hence the primary jets need to be richer, the secondary jets don't need to go up much more. Time required for making of erection is generally. The engine MUST be set-up so it will work for the applications, and/or how it is intended to be used & driven. IDLE JET Both the DCOE and IDA carburetors have an idle jet assembly, which meters both fuel and air into the idle circuit. Holley 4 Barrel Carburater Information List Numbers and Stock Jetting. 4 carburetors were used on CJ2A over the years: Group 12-04 -- Carburetor p/n 640304: Carter WO, type 596s - up to s/n 69589 p/n 643337: Carter WO, type 636S - after s/n 69589 up to s/n 212110. Carburetor Specifications. Float Level * Derivation; DGV & derivitives: 28/30 DGV 14A 22550. In the IDF and DCNF, the idle air is "fixed" via the air bleed, and that's why they have idle jets available in increments of "2. Do 8 Stack EFI or Weber Carbs Run Good On The Street? The answer isn't so simple, but overall the answer is no, not as well as you think, or as they advertise them to be. Weber made an absurd number of variants of the 32/36 (and even licensed one to Holley for the 5200). It's a Weber 38/38 synchronized 2 barrel DGES with electric choke and oversized jets. The rest of the chart is just for approximating what percentage of sea-level horsepower will be produced by a correctly-jetted engine at higher elevations. Idle Jets and tuning the idle circuit: Very Simply. Just be positive to use the same one jet number at a time approach (above), and always (always) double-check the spark plugs. A Stage 1 Carb Kit will normally offer you a proper range of jets for your particular model. occurring with the mixture screw set at 3 turns from bottom, indicates the need for a larger Idle jet. Now that Ive done the adjustment, no more dripping fuel. 702 IDF-1 702 IDF-2. 95: Manifold Hose Clamp 40-60mm $5. The cure for this problem is to install larger idle jets. Rialto, CA 92376, USA 909 605 1123. Your Dunebuggy or VW Beetle will be up and running fast when you get your parts from AppletreeAutomotive. The Weber DGV was originally designed for a 6-cylinder European Ford. VHBZ and VHBT have a separate needle and seat. but it is about as good as I can. 55 Accelerator Pump Jet - 1. Superior float design for excellent fuel control. Carbide Drill Bit Set for Carburetors Auto & Motorcycle. Remove the jets and insert a smaller/larger set based on the vehicles operating altitude. 5mm fuel hole and the F8 Refers to the Air Bleed hole in the side. Is there anyone out there who has experience with a Weber DCOE 45 on a 1275 mini? Or even better is there anyone out there who has experience with one at altitude? The current jetting for the Weber 45 DCOE 13 is: main jet 160. 50-60 is the range of sizes used by the 1. WEBER CARBS, Carburettors, Jets, Emulsion tubes, Conversion Kits, Air Filters, Linkages, Rebuild Kits, carbparts. Find your favorite car logos, car emblems, car company logos, car manufacturer logos and names at Carlogos. You can change parts between them. A 50 Idle jet is a. There are TWO different types (no. Idle Jet. I'm not sure how much power the 196 should have, but with the weber there is very little low end or high end power. At 7,200 feet, an engine will produce about 75% of its rated horsepower. weber 48 ida weber 3bbl porsche ferrari float spring: $18. Idle jet 60 The main jets on mine are 117 / 127 as listed. The bigger the number the richer the jet. Datsun L Series Weber Downdraft Manifold 99002. I am assembling a set a of Weber 40 IDAs for my friend's 2. On the DCOE and IDA series carbs they have 2 numbers on them like 50F8. Picture an old windup desk clock. One of the most common problems with this carburetor is an erratic idle; in extreme cases (as it was with my. - 42 Weber Type Idle Jets - 42 Weber Type Main Jets - 48 Weber Type Air Jets - 48 Weber Type Idle Jets - 48 Weber Type Main Jets - Solex Air Jets - Solex Idle Jets - Solex Main Jets • Ball Type Needle and Seat - Dellorto - Needle and Seats - Solex - Stock 48 IDA - Weber • Weber • Solex • Dellorto • Stock 48 IDA • Tall Jet Holder. Emulsion tube F50, main jets 140/140, air correctors 170/180, idle 60/50 You can ask for change main, air, idle and emulsion tube for free - no extra cost ! Manufactured by FAJS. Weber Idle Jet, IDF, DCNF. but then you would lose something on the other end when you want to drive normally. Some are even mirror images of each other, but they all have the same basic jet/corrector layout. Any less and it just dies out. 5 aux vents. Adjusting the Motorcraft 2 barrel carburetor to the proper settings will provide you with more performance and better fuel mileage. The Weber 34 DGEC supposedly arrives 'pre-adjusted. A two step metering rod is used to control the fuel on the primary side. 94 per/jet 74405. Checked the mixture at idle with the colortune, No1 cylinder was ok, richened it slightly. Those carbs have a plug that blocks off the squrit from the accel pump jet into the secondary venturi. As with the emulsion tube, the idle jet is chosen based upon the. DIR, DPS IBF, IBSA, IBSH, IBP ICT, ICH Please click on the drop down to specify the size you would like to … Continue reading →. 1600cc 40/45. One of the most common problems with this carburetor is an erratic idle; in extreme cases (as it was with my. When set up with a progressive throttle linkage, such as Speedway part number 5606271, this type of three-carb system will operate like a modern four-barrel carburetor: idle and cruise on just two barrels, with the secondary carbs letting in more air and fuel as the engine needs it. weber 44 idf sizes air correction 1 75 emulsion tube main jet 1 35 pump jet ole jet venturi note: 2mm e i n val factory weber 48 idf sizes air correction emulsion tube main jet 1 so pump jet ole jet venturi 40 mm note: 2mm e i n val facto ry weber 34 ict sizes air correction emulsion tube f_78 main jet pump jet ole jet single carb 160 1 45 (d). After settling on 77/86 primary/secondary jets, we achieved 479. I need to rejet it but it was an BMW 2002 Jetting and Tuning - Weber 32/36 Carburetor Today we continue to mess around with the engine to get it to run great. The progressive idles through barrel and one mixture screw hole, then transitions to a secondary barrel with an additional Idle / low speed jet. F = main jet, controls fuel mixture in the emulsion tube as cruise circuit is activated G = emulsion tube H = air corrector jet, affects only performance at high RPM I = idle jet, affects idle and progression circuit J = accelerator pump jet K = accelerator pump inlet valve with exhaust orifice (also called a discharge bleed). An absolute "must have" for anyone installing or tuning Weber carburettors. I just found the idle jet passage down to the mixture screw is obstructed on the 2 1 side. 5mm fuel hole. Approximately 60% of the time when you are driving, the idle jets will be what is primarily supplying fuel to the car. Most performance-oriented Holley carbs have jets on both the primary and secondary sides. 50 IDLE JET. Most do not have the equipment to properly drill ou the jet and the needle to jet relationship is degraded. The edge of the whirl was represented by a broad belt of gleaming spray; but no particle of this slipped into the mouth of the terrific funnel, whose interior, as far as the eye could fathom it, was a smooth, shining, and jet-black wall of water, inclined to the horizon at an angle of some forty-five degrees, speeding dizzily round and round. Get behind the wheel of these premium, exciting, and surprisingly spacious vehicles—experience a MINI today. 5 turns out. Look for sku VM28-49 JavaScript seems to be disabled in your browser. Craftsman makes a wide variety of tools and equipment for everyday use. turn the idle adjustment screw about 1. Weber 32 ADFA and 34 ADF Carburetors Reference Guide Brad Artigue. Only 5 left in stock - order soon. 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). I see fuel dripping from the carburetor boosters at idle, what causes this? Too much fuel pressure usually causes this and often times dirt in the float bowls can do the same. Every engine responds differently, and final jetting changes are most often determined by the engine builder or tuner. For more information on these idle jets please see this technical sheet: DCOE idle jets For twin barrel Weber […]. 5 aux vents. Runs and idle well. Your Location: Altitude, Temp. Whether competing for a prize or for the simple joy of it, this is a pastime many people dedicate their time and energy to for the fun of it. You have a carter BBD carb, this is one of the worst carbs in history (which is why i got rid fo mine for a weber). 9 Using tag wire, clean the idle circuit fuel pick-up that is located in the center leg. I subsequently turned it more in by about a full turn. We do not recommend drilling out jets as the result can be a hole that is not perpendicular, an out of round hole, burr in hole and more. JET DRILL SET AND VICE £37. You can order this book from The Performance Parts Warehouse Another excellent sources is Advanced Performance Products they carry a complete line of ram pipes, jets, air filters ands ancillaries for the DCOE. I got them from Lynx along parramatta road and i think they got them in from england, they cost a small fortune then, probably thirty years ago now. It is often the port on the front passenger side of the carb, in the throttle body nearest to the idle mixture screw. venturis 3. Holley carburetors have powered every Monster Energy NASCAR® Cup team and nearly every NHRA® Pro-Stock champion for four decades. However, I’ve found a bunch of posts on the web claiming these to be both the 1. One of the things we noticed over the years is the lack of information concerning Holley List numbers and the specifications for individual carburetors and their stock jetting. You can then switch between the drawing and this page here as the numbers in the. 289/302, 351, 429/460, Etc. The most frequently asked question about our Weber kit is “Do I have to re-jet the carb for my engine?” Re-jetting is the last, and perhaps the most important function of install-ing the Weber conversion. By "jet sizes" I am referring to all of them (main, idle, air correction, emulsion), and by "locations" I am referring to which sizes go on which side (primary and secondary). by Jeff Barringer - Staff Photographer Formed in Richmond California, thrash metal band Exodus is the opener for Slayer on their current tour, with guitarist Gary Holt doing double duty and filling in for fallen guitarist Jeff Hanneman during Slayer's headline set. If your stock main jet is a 100 (stock size in a 22mm Mikuni) you will find this jet size falls between the #62 & #60 drill bit. Idle jets have two numbers; the first is the size of the fuel orifice , while the second ‘f’ number, is the air bleed (also known as the air drilling, see Figure). 5 aux vents. The world's premiere manufacturer of charcoal, gas and electric grills and accessories, Weber also features the best grilling recipes and maintenance tips. The carb has its stock jets and to get it to idle correctly the idle adjustment screw has to be screwed all the way in. It is also important that your carbs are correctly balanced. The only jets you did not list is the 2 most important Primary and Secondary Idle jets these, control your fuel from idle to about 3k rpm's where most of your driving occurs. 74822 Weber Idle Gas Jet Choose your jet size and select as many as you want of each size. 056: 23/24(1) 3. Unbalanced carbs can cause unwanted engine vibration and inconsistency of jetting results. So to go richer one size from a 55 idle jet, we would choose a 60. Edelbrock Carter AVS #4429 2 idle circuit srews base plate under lead #1. You can also see the 6 screws holding the top of the carb on. 825 Datsun L Series twin side draft manifold 99003. Weber Jetting Chart: Included in the chart is info on the following carb "families"; DGV | DCNF Main Jet. The amount of fuel passing through a given jet changes according to the pressure drop applied to it. Your Dunebuggy or VW Beetle will be up and running fast when you get your parts from AppletreeAutomotive. We Deliver you a completely tested, calibrated, and idle adjusted marine carburetor for single or twin engine application. Below is a chart showing approximate idle jet sizes for given engine sizes, this assumes one carb barrel per inlet port E. By the fact that you say it does not run without some choke, says it is too lean. Most do not have the equipment to properly drill ou the jet and the needle to jet relationship is degraded. 25 turns, the throttle plates are closed, and manifold vacuum level should read 18 to 20 at idle on a sound engine. Achieving the best idle at under 2 turns indicates the need for a smaller idle jet. Checking the idle speed Check the idle speed when the engine has reached the operating temperature. Below is a chart of the new and old Holley 5200 jets according to flow thus a 124-311 green jet would have close to the same flow as a 22R-103-147 jet. In the IDF and DCNF, the idle air is "fixed" via the air bleed, and that's why they have idle jets available in increments of "2. For more information on these idle jets please see this technical sheet: DCOE idle jets For twin barrel Weber […]. The secret to understanding the critical nature of the carburetor set up and the advantages of a WEBER over other carburetors is the idle circuit. I have a 78 with rebuilt carbs. Take note of the size and position of this jets as it's easy to mix up with the power (Aux) jet next to it - they will happily screw into each other's position. When the operating altitude of the engine will be 2000 feet higher than your normal altitude, you'll need to insert a jet one or two sizes smaller than the size currently installed in the carb, which reduces the amount of fuel entering the engine to match the reduced level of oxygen in the air. Problems Carburetor doesn't adjust properly Carburetor floods Fuel leaks at shaft Internal fuel leak Misses or surges Stumbles or loads up Engine won't idle Rough idle Backfires Bogs Hard starting Lack of power Pinging at moderate cruise just off idle Engine stalls on hard braking Low fuel economy Possible Solutions. This was the carb of choice among factory entries and racers in the heyday of the MGB, and coupled with the reliability inherant in the design, it powered the B to many finishes above more. Now I have 125/125 jets with 165/170 air correctors and still the same idle jets. 80; 2 x Air Corrector (short) 7482. Choke has been set, idle mixture adjusted, idle adjusted, float has been adjusted. Our VW weber carbs include Weber progressive carburetors and single Weber carbs. Main Jet Emulsion Tube Air Correc. a Calibration Reference Chart for your model of carburetor has been included. With the engine fully warmed up and idling, slowly turn them in (do one at a time), and CAREFULLY listen to the idle quality and speed. My choke/high idle cam don't work properly, so in the event of a hard start; manually close the passanger side butterfly valve and it will fire right up. First chart shows data for 105 series. The 50 refers to the. 50 Auxiliary Venturi 1. I subsequently turned it more in by about a full turn. The idle jets sit inside those holders. We also stock a large selection of vintage marine carburetors. It is often the port on the front passenger side of the carb, in the throttle body nearest to the idle mixture screw. That drain (bottom of carb) is attached to a brass tube, in the float bowl, which allows 'excessively high' levels of fuel to drain away, keeping the carb from overflowing into the enginethe float itself has a metal tang, which bears upon the 'spring tip' of the float valve-you can bend this tang, 'VERY SLIGHTLY', to effect a small change, to raise or lower the fuel level, in the float bowl. Emulsion tube F50, main jets 140/140, air correctors 170/180, idle 60/50 You can ask for change main, air, idle and emulsion tube for free - no extra cost ! Manufactured by FAJS. Superior float design for excellent fuel control. By the fact that you say it does not run without some choke, says it is too lean. Then fiddle with the mixture crews, then idle jet and idle air-correction (the F# on the idle jet). 25 Main Jet. REBUILT! 5228A5 WMK-13-3 Mercury 1973-75 Bottom Carburetor Assembly 65 HP 3 cyl. Adjusting the Motorcraft 2 barrel carburetor to the proper settings will provide you with more performance and better fuel mileage. Below is a chart showing approximate idle jet sizes for given engine sizes, this assumes one carb barrel per inlet port E. 5 increments (150,155,160,etc), a "150" main jet has 1. Main jet: 110 Idle jet: 50F11 Emulsion tube: F16 Air corrector jet: 200 Accelerator pump jet: 35 Accelerator pump back bleed: 70 Needle valve: 150 1300 GT Junior Super. Guaranteed lowest price! Open 24x7 - Same Day Shipping! $10 off $299+, $20 off $599+, $30 off $799+, $100 off $1,599 Orders. 2000cc 50/55. Weberjets - Home of Weber Carbs. Brief Pictorial - Idle Jet Cleaning on Weber 40 IDA 3C Suspected idle jets and had some assurances from others on the board that was likely the case. Holley 4 Barrel Carburater Information List Numbers and Stock Jetting. However, I’ve found a bunch of posts on the web claiming these to be both the 1. Generally speaking, anything you add to gasoline or motor oil that comes in a can is useless to harmful. 550 RPM with ILC extended. It just is what it is. We also stock a large selection of Vintage Marine Carburetors. 95 GBP (ex vat). For example, a 145 in the main primary to a 140 in the main secondary. For those who want to use modern tires you will find a conversion chart here. My weber uses the big style idle jet on the primary and then the small style on the secondary. The cap jet should then be adjusted to the suggested flow rate and must always flow greater than the compensator jet by 30 to 40 ml/min. Dirt in the idle jets will make the car run sluggish, as if you have lost power in a cylinder. 14 You Save 17%. Float Level * Derivation; DGV & derivitives: 28/30 DGV 14A 22550. 356 Carburetor Rescue offers remanufacture of all the following: Early Porsche 356 engines used Solex carburetors. JET DRILL SET AND VICE. After that the mains take over. O-Ring For Idle Jet Holder. 5 aux vents. Weber & HPMX Single 40 IDF Jetting: Venturi: Main Jet: Main Air Corrector Jet: Emulsion Tubes: Idle Jet: Pump Jet: VW Type 1: 1500 - 1600CC: 28mm: 145: 160: F11: 65: 75. Weber OEM Jetting Table OEM Jetting Table Included in the chart is info on the following carb "families"; DGV | DFV | DFTA/DMTR | DCNF | DCOE | IDA | IDF | ICH/ICT. Re: Jetting a 40 DCOE for 1275 We've got the Yellow Sprite with the Weber that has given us yeoman service on a 948 plus I've got two Weber 40 DCOEs lying around with one goose-neck manifold. The BBS and BBD are coming soon to a different page. idle jet 50 f8. 3 Main Jets. Main jet replacement should be reserved until after the slow idle jet is replaced and mixture is tuned unless a lean condition is apparent during full throttle. The idle jets are specific to the PMO and IDF. If you are fortunate enough to have one of these harnesses, you can usually just tap off of one of those feeds. The 50 refers to the. Make sure it is not more than 2. For example, a 40 IDF would need a 40 x 1. The smallest orifice in the Weber is that of the idle jet and thereby the most susceptible for blockage. 40 Air Corrector Jet 0. Better Than Human: Why Robots Will — And Must — Take Our Jobs Baxter is an early example of a new class of industrial robots created to work alongside humans. The main jet affects the jetting in the upper quarter of the throttle position. 32 PBJ, and more commonly, 32PBIC / PICB on Normal engines, and the idle jet 50 50 55 idle air correction jet 120 140 140. When the operating altitude of the engine will be 2000 feet higher than your normal altitude, you'll need to insert a jet one or two sizes smaller than the size currently installed in the carb, which reduces the amount of fuel entering the engine to match the reduced level of oxygen in the air. Re: Holley Jet Sizes / Drill Sizes 11-08-02 05:54 AM - Post# 134515 In response to Carnut427 as indicated, holleys method of determining jet flow is kind of strange. On the subject of ongoing jet changes, I re-installed the 60 idle jets (1600cc weber 34 ICT blah blah) and lo & behold, the light throttle and off idle response has indeed returned to it's previous smooth response. It's a Weber 38/38 synchronized 2 barrel DGES with electric choke and oversized jets. Imperial Hwy Brea, CA 92821 1-877-405-4345. Nowadays buy generic levitra has been touted by diverse media sources and advertisements as being the greatest treatment on the market. You have a carter BBD carb, this is one of the worst carbs in history (which is why i got rid fo mine for a weber). At 7,200 feet, an engine will produce about 75% of its rated horsepower. No man likes a weak squirt. Lowered the float setting just a little (took the needle-nose and eyeballed it) Those three things together made a huge difference in the Weber. Brief Pictorial - Idle Jet Cleaning on Weber 40 IDA 3C Suspected idle jets and had some assurances from others on the board that was likely the case. air jet 175. At idling speed the idle mixture adjustment can be set to control the volume of mixed or emulsified fuel and air provided by the idle jet assembly and if a correct jet has been selected the setting of the. Hi have a Tecumseh tvxl220 and having trouble with carb and govenor linkage connections , hard Ta start and will over rev. 170; This was quite a shopping list as the jets and emulsion tubes are only available from a few outlets. The Pierce Manifolds Weber tuning manual is my main source of information. Adjusting. 95 GBP (ex vat). Your order may be eligible for Ship to Home, and shipping is free on all online orders of $35. The first thing we do is match the stock main jet to its corresponding numbered drill bit. 1 bluetooth receiver for car. The 50 refers to the. Idle jet 60 The main jets on mine are 117 / 127 as listed. Gimpy, those Weber idle adjustment instructions are really good at explaining how (and why) to adjust idle mixture screws. Please use our vehicle and product searches below to find the correct application for your specification or have a look around our web store to find a range of other accessories to fill your needs!. Garden product manuals and free pdf instructions. 1700cc or larger engine with GB 856 heads or better required. Later versions of Weber throttle bodies incorporated an o-ring seal to help assure no un-metered air would interfere with the emulsification of the fuel in the idle jet/air correction jet area. Further experimenting with reducing the main jets from 72 to 69 and using a slightly larger. au An Explanation of the DCOE Weber idle circuit looking at idle jets, progression holes and mixure screws. The Jeep 258 (4. In the IDF and DCNF, the idle air is "fixed" via the air bleed, and that's why they have idle jets available in increments of "2. i've played with an edelbrock 1405 on a mild built ford 302 and found that the factory settings were way too rich too. i haven't tested the winter blends yet, but i know the summer blend i had was 83% when you were at the Union race. Identification 34 DMTR 87/250 Idel speed [rpm] 750 Fast idle speed [rpm] Stage (venturi) 1 2 Venturi diameter 22 24 Auxiliary venturi [mm] 4. 001: 21/22: 4. Displaying items 1 - 3 of 3: Sort: 20 Piece Carburetor Tuning Drill Bit Set Holley Rochester Carter Mikuni Walbro. Idle Jet F10 for 48IDA only. i had tripple 45's and after fighting them for quite a few round of jets i went to the z-therapy su,s over bored small shafts and wow what a difference smooth idle lots of power and with a high compression l-28 and big cam i havent ran out of top end yet ,cats meow ---lions roar with a itg filter and twm horns mmmmmmmmmmmm good stuff always starts and ready to whip a** ,cant say the same for. Its the one in a channel heading down to the boottom of the carburettor. 5mm fuel hole and the F8 Refers to the Air Bleed hole in the side. - DCOE Air Jet - DCOE Idle Jet - DCOE Main Jet - DCOE Pump Jet - DGAS, DGAV, DCD Main Jet - DGAS, DGV Air Jet - DGAS, DGV Idle Jet - DMTR. Don't forget the idle circuit can contribute fuel metering at light cruise up to maybe 50mph. possible, however, unless all of the available adjustments have really been optimized on each carburettor type and on the same engine. An example of an idle jet for a DCOE carburetor. Perfect copy of the factory throttle quadrant setup for all RHD 105/115 series cars. Once the idle circuit is working you can play with the primary circuit. The primary idle jet is inside of the idle cutoff solenoid, which is at the bottom of the photo off the passenger side of the carb. 25 the size of the throttle body. The F designation indicates that this jet controls both air (side inlet hole) and fuel (inlet hole at the tip). Weber 32 ADFA and 34 ADF Carburetors Reference Guide Brad Artigue. 65 Primary Air Jet - 1. Please use our vehicle and product searches below to find the correct application for your specification or have a look around our web store to find a range of other accessories to fill your needs!. 8 air corrector (richest) and it's still too lean, then go to a larger idle jet (like from 40 to 45 or 50 to. First Start - Toyota 20R Weber 32/36 Carb - 1977 Pickup/Hilux/Chinook] Finished installing the new Weber 32/36 carb, and a Pacesetter Header on my 20r. 29 GENUINE Keihin jet size 110. At idling speed the idle mixture adjustment can be set to control the volume of mixed or emulsified fuel and air provided by the idle jet assembly and if a correct jet has been selected the setting of the. Sep 07, 2011 · Anoth qu is what size jet & slide weights are u running? I'm sure I need a bigger jet, my polini air filter is a cone shaped foam type with a cap on it w holes. Of course, the millionaires among you will scoff at this, so please ignore. Jet storage is also important. Secondary idle jet 10-15 larger than primary idle. The DGV is a dual-barrel downdraft progressive carburetor. Further experimenting with reducing the main jets from 72 to 69 and using a slightly larger. Engine is bone stock. 14 You Save 17%. idle jet enrichment drill kit pm4007. Weberjets - Home of Weber Carbs. Another common problem with Weber carburetors is that they sometimes spit out the top of the velocity stacks. However sometimes in a pinch drilling out a jet will be needed. The floats are center hung and they are hollow plastic material. How to Adjust Motorcraft 2 Barrels by Carl Pruit. weber 44 idf sizes air correction 1 75 emulsion tube main jet 1 35 pump jet ole jet venturi note: 2mm e i n val factory weber 48 idf sizes air correction emulsion tube main jet 1 so pump jet ole jet venturi 40 mm note: 2mm e i n val facto ry weber 34 ict sizes air correction emulsion tube f_78 main jet pump jet ole jet single carb 160 1 45 (d). Further experimenting with reducing the main jets from 72 to 69 and using a slightly larger. 48 IDA Weber Idle Jet Holder Sizing I'm trying to write down, again, what I had done with my Jetting before my computer died & took the info with it. FREE Shipping. By Rob Robinette. Do 8 Stack EFI or Weber Carbs Run Good On The Street? The answer isn't so simple, but overall the answer is no, not as well as you think, or as they advertise them to be. I have every needle, main and idle jet available for the Mik48 and think I used everyone of them chasing the tune. Just curious, and I know theres no 'exact' answer, but what type of altitude change would warrant an adjustment of the carb and when adjusting for altitude, do you richen/lean only H or L or both. Some carburetors have a slow speed fuel adjusting screw that regulates the fuel/air mixture in the lower rpm range. Whether competing for a prize or for the simple joy of it, this is a pastime many people dedicate their time and energy to for the fun of it. This is the opposite from most 4 barrel carburetors, where the secondary jets are bigger than the primary. I've also got several sets of the 948 SU carbs, and may have some of the larger ones in a bin about an hour and a half away. A 44 IDF would need a 55 idle jet, and a 48 IDF would need a 60 idle jet. 32 PBJ, and more commonly, 32PBIC / PICB on Normal engines, and the idle jet 50 50 55 idle air correction jet 120 140 140. One of the most common problems with this carburetor is an erratic idle; in extreme cases (as it was with my. 065 Idle Jet 065 74405.