carter wcfb carburetor adjustment
Adjust idle screws D to produce a smooth idle of correct speed is obtained. You can also check the adjustment by measuring (F) which should be 18/64. Inspiration for this arrangement was provided by the federal government through its exhaust emissions regulations. Is there a pointed check weight in the main discharge hole. pump rod until the top of the pump arm is horizontal (or the screw that retrains it is perfectly vertical, if you prefer). Ultra-Sonic Cleaning3. Make sure the pontoons are centered and will not rub the bowl sides. Check throttle linkage to make sure that primary throttle valves come to full wide open position. BBS) and were basically an on/off condition similar to the function of a power valve. The distance from the dust cover boss to the top of the plunger shaft should be 1/2 inch (distance from base to tip of finger on gauge) (C). Because the float is maintained in a level position, needle valve bounce is minimized and excess fuel entry into the bowl is prevented. Install the pump connector rod (D) in the outer hole, long stroke. As the engine gains in RPM, the vacuum drops and the metering rods are pulled out of the main jet allowing more fuel to flow. DO NOT apply any pressure on the needle. Metering rods for the WCFB have been out of production for several years now. As for the pump not squirting.I suspect the pump well isnt filling up. Check your auto manual for the spec, but somewhere around 4-5 lbs would be good.Be sure the power piston is not frozen in one position. Make sure these are clear if you have percolation problems. Carter WCFB 4 Barrel Carburetor Float System. What Has Been Done to This Carburetor?1. All late model WCFB carburetors have three different length bowl cover screws. Secondarys are somehow stuck open (which amounts to a vacuum leak). The Carter WCFB carburetors have a square-ish body with a rectangular air horn that protrudes above the air. *New Accelerator Pump5. Fuel pump working as it should (pulsates and sprays gas each time cam lobe activates it). The Carter WCFB, 4 barrel carburetor metering rods are used to meter the fuel getting into the carburetor bore. One of the butterflies is open about 1/8 with the carburetor dis assembled. Carter WCFB Accelerator Pump Quick test to see if the accelerator pump is working. Measure from center top surface of pontoons to air horn. Correct by removing any burrs or nicks. Rotate screw C, or bend tang, until throttle valves are open the distance listed in, With throttle valves held wide open, there should be a clearance between upper edge of choke valve and the inner wall of air horn (. a. Aspringis inserted in the power piston hole, then the piston. You cannot go wrong with Mikes carburetor in any way. Look for breaks in the new gasket, or cracks around the threaded area.The needle could have been damaged while adjusting the floats. Must be made after fast idle adjustment. Seat the discharge check by tapping lightly in the hole to form a good seal. Founded by William Carter in 1909, the Carter Carburetor Company produced units such as the AVS, AFB and 385-CFM WCFB for dozens of years. The float lifter spring also provides better float and fuel level stability when operating on rough, washboard type roads.A balance passage connects the primary and secondary float chambers to provide fuel level control when the vehicle is accelerating, stopping, or rounding curves. Test the needle by holding it down gently with a brass drift punch. With the thermostatic coil housing gasket and baffle plate removed, crack throttle valve and hold choke valve closed. Contact Us Home Blog FAQ's Technical Help My Account LoginRegister Examples of Carb Numbers search 0$0 Carburetor Parts by Make & Model Scroll to see more Aero Coach Carburetor Parts Alfa Romeo American Bantam American General American LaFrance American Motors Nash Rambler Auburn Audi As the accelerator is released and the primary throttle plates are closed to the idle position, the upward movement of the pump plunger and attached spring bracket exerts tension on the spring and tends to stabilize the float in a level position. This restricts the flow of fuel. Technical Details. Fuel enters the primary side of the carburetor through a strainer screen at the fuel inlet and is directed to the primary needle valve and seat. The metering rods must be installed after the pump adjustment or when leaner than standard rods are installed. Fuel enters the primary side of the carburetor through a strainer screen at the fuel inlet and is directed to the primary needle valve and seat. When Quadrajet carburetors have Carter's basic four-digit identification number before the letter S, the carburetors are aftermarket replacements. A bushing (sorry dont have size) can be permanently installed in the choke vacuum passage in main body casting provides a more positive seal at this point, and prevents fuel from leaking into this passage on left turns and stalling the engine because of too rich a mixture. Ideas?? Everyone Has Started an Engine in the . b. Hold in place and carefully tighten metering rod arm set screw (G). Do not depress float lip against spring in needle, but let float rest of its own weight. Note te larger box, and the number of additional tools from the 1935 set. Can't find the answer you're looking for? Adjust by bending float arms, making sure both pontoons on each float are the same height. Carter WCFB 4 Barrel Adjust Float. Check the low speed jets to make sure they are clear (#44). . Any bubbles indicates a leak.Make sure the 2 floats are the same height. Also check for overheating of the engine, fuel lines too close to the manifold, or too much heat in the engine department. Back out throttle lever set screw until throttle valves seat in bores of carburetor. FREE to our customers that buy a rebuild kit. intro Carter WCFB 4 Barrel Carburetor Rebuild Mikes Carburetor 21.5K subscribers Subscribe 51 Share 3.1K views 9 months ago Disassemble & assemble your Carter WCFB 4 barrel. Adjust idle screws D to produce a smooth idle of correct speed is obtained. The main body is partitioned into two compartments (primary and secondary), each containing a double pontoon float and lever assembly and a needle valve and seat. Make sure the pump relief check is clean. Make sure the ball rattles. A fuel pump cannot be tested by unhooking the line and seeing if gas comes out. Carter WCFB 4 Barrel Carburetor Float System, Engine wont idle, or dies after the choke is opened, or runs better when choke closed. Access our free Idle Speed and Mixture Repair Guide for Chevrolet Corvette 1963-1982 through AutoZone Rewards. Blow air through the main discharge to make sure the passage is clear all the way to the pump well. To prevent fuel from being drawn through the pump circuit, the passage to the pump jets is vented by a cross passage to the carburetor bowl above the fuel level. Why Doesn't Adjusting Idle Mixture Screws Make any Difference? The adjustment of the pump is important in order to get the required fuel. Adjust by bending throttle connector rod at upper angle (B). The metering rod adjustment should be done after the pump adjustment. Rebuilding Carter BBD carburetor part 3 - Duration: 5:04. How to Adjust a Carter BBD 2 Barrel | It Still Runs The Carter carburetor has been around for a very long time. The download link can be found on your order confirmation email which you will receive as soon as you complete the order. 1: Carter WCFB idle mixture and speed adustment screw location. The setups data is the same. As the throttle is opened the pump moves down the pump well forcing the intake check closed and forcing fuel out the main discharge. If adjustment is required, remove dust cover and bend arm that operates the vent mechanism. See figure 9F-2.A float lifter spring, which is connected to the lever arm of the primary float and to a bracket on the accelerator pump plunger, is incorporated to stabilize primary bowl fuel level and prevent float bounce upon sudden stops, or on rough roads (these springs are nowhere to be found). The most complete document I have found. Do not depress float lip against spring in needle, but let float rest of its own weight. 60 pages of great info. I purchased from you a rebuild kit for Carter WCFB 4 barrel carb on my 1955 Chev. *New Float6. They sometimes need trimming. The flat surface of the pump arm should be parallel to the straight edge. Carter WGD Adjustments Float Level With bowl cover assembly inverted and float resting on pin in seated needle, and with gasket removed, the distance from the bowl cover to the top of float should be 7/64. Recheck float adjustments. He only had 5-years of formal education and in 1909, he founded the Carter Carburetor Manufacturing Co in St. Louis. Both Carter and Rochester engineers determined that, on some applications, the float level in the primary side of the carburetor should be different than in the secondary side of the carburetor. The Carter AFB uses weights, and therefore never goes out of adjustment. How to clean the Jeep Carter BBD carb Idle jets - Duration: 7:14. These diagrams include: Fig. Carter WCFB, 4 barrel metering rod adjustment instructions. Watch on. When closing the throttle, the accelerator moves up in the pump well. I rebuilt a Carter WCFB carburetor with the lower auto choke setup. See figure 9F-2. One is in the secondary venturi and the other just above the throttle plate. Eckler's Premier Quality Products 57132129 Chevy Carburetor Rebuild Kit Carter WCFB Replacement Kit Includes All Gaskets, Seals, Check Balls, Springs, Accelerator Pump & Needle Valve Read more CARTER 4 Barrel WCFB DUAL CARBURETOR KITS & FUEL FILTERS 1961-65 CHEVROLET 1955-56 DESOTO April 18, 2018 Carter Carburetors Rebuild Kits There should now be 9/64 clearance between upper edge of choke valve and inner wall of air horn. This is caused by side strain on throttle lever due to misalignment and maladjustment of the carburetor interconnection rod. Carter WCFB 4 Barrel Carburetor Float System. Kit looked complete but I ordered the wrong one based on the pump and of course with it being opened, it cannot be returned. Carter WCFB, 4 barrel carburetor manual. 1955 Pontiac - Loading or Carburetor Flooding With choke valve held closed and fast idle adjusting screw C, or fast idle adjusting tang, on high step of cam. The correct way is to use a fuel pump pressure gauge. It isn't unusual for the vacuum piston on the WCFB to become frozen in the cylinder where it resides. When done you should see very little daylight around the valve. Carter WCFB Adjustments Metering Rod Adjustment Back out throttle screw so that the throttle valve close completly. With carburetor installed and engine warmed up. Add a couple drops of oil to the leather. The main body is partitioned into two compartments (primary and secondary), each containing a double pontoon float and lever assembly and a needle valve and seat. Can you help me out? 1963-64 Studebaker Carter AFB 1962-1965 Chevrolet 327 and 409 engine carburetor manual 1958-1968 Lincoln carburetor manual AVS 1966 Chevrolet 327 and Marine Carter AVS carburetors BB Ball and Ball Single Barrel downdraft manual: 1939-60 Chrysler, Dodge, Plymouth Carter BB, BB1, BB1A and BB1D updraft Carter BB for IHC BBD The Solid fuel is the later models BBDContents:00:00 intro00:34 air bled adjustments00:37 air bled float setting01:03 air bled fast idle type I01:25 air bled fast idle type II01:42 air bled fast idle type III01:58 air bled unloader02:24 air bled choke vacuum kick03:01 air bled automatic choke03:16 air bled pump04:08 air bled dashpot04:27 air bled idle speed \u0026 mixture04:58 air bled emission carburetors idle mixture06:00 air bled limiter cap06:36 solid fuel adjustments06:40 solid fuel float setting07:03 solid fuel metering rod07:27 solid fuel accelerator pump07:55 solid fuel bowl vent08:18 solid fuel fast idle cam08:43 solid fuel choke pull-off09:12 solid fuel automatic choke09:24 solid fuel egr dump valve09:46 solid fuel unloader10:08 solid fuel high altitude10:28 solid fuel idle speed \u0026 mixture12:11 solid fuel Limiter cap12:37 solid fuel fst idle12:51 solid fuel throttle positioner13:56 solid fuel vacuum throttle positioner14:31 solid fuel sol-vac15:04 solid fuel dashpot15:28 solid fuel transducer Make sure the air cleaner gasket does not block the bowl vents. *New Main Body Gasket8. This is an electronic rebuild manual, no physical copy will be provided. 1955 Cadillac Idle Air Mixture Circuit WCFB Carburetor Cutting Out on Left Hand Turn Some models have a pump relief check in the bottom of the fuel bowl. With throttle valves seated in bores, dust cover and gasket in place. I. DISASSEMBLY. 19591961 Chevrolet Carter WCFB Carburetor All These Part Numbers Interchange Into Our Part No. When that is the case, I bend the accel. The ends of the connector rod should point to the throttle arm side. The bowl vent is used to vent the float bowl, otherwise a siphoning of the gas can occur. When I slow down to an idle, my engine runs rough. Back out throttle stop screw until throttle valves seat in bores. If a loss of rpm is noted, or if the engine dies, and air leak exists. The vacuum piston is no longer produced and can only be found as a NOS piece, or used. Carter WCFB 4 Barrel Accelerator Pump Circuit Carter BB Carburetor Assembly Part 1 of 2 Rochester Quadrajet Idle Tube Removal Tunning Rochestor Quadrajet 4 barrel Carburetor Mark Osborne. The adjustment of the pump is important in order to get the required fuel. The WCFB carburetor which came on some of the earliest From my experience it is the most complete and comprehensive source for all things carburetor, encompassing a massive spectrum of makes models and applications. Other 4 barrel carburetors such as the Carter AVS, Carter TQ, Rochester 4GC, and Rochester Q-Jet have a tensioned secondary spring. Low fuel pump pressure always check you motors manual for the correct pressure. Adjust by bending lip of float, not float arm. Place the choke housing toward the left and remove upper right main body to throttle body screw. Good quality print. Carter WCFB Fast Idle With carburetor installed and engine warmed up. Use a brass drift punch. In my repeated attempts to get the accelerator valve to pump, the car has run for several minutes combinedplenty of time to get the float bowl full. The suction along with the fuel weight pulls fuel through the intake check via the passage to the fuel bowl. Adjusting the WCFB Metering Rods The Carter WCFB, 4 barrel carburetor metering rods are used to meter the fuel getting into the carburetor bore. Carter WCFB Build Sheets Change the choke setting to index. It's highlighted yellow and will look something like this. Coat threads of screw with sealing compound and install it. Older kits 30-70s. Put some fluid in theaccelerator pumpwell and press down on the pump. Carter built the first successful 4 barrel carburetor, the WCFB (Will Carter Four Barrel) which first appeared in 1953 on Buick cars. Will Carter introduced the world's first 4-barrel carburetor, the WCFB (Will Carter Four Barrel) which raised air-flow to unprecedented levels. Run a blunt object around the inside of the leather cup to make sure any coating is broken. When adjusting the screws doesn't change the RPM then it means there is a problem with either the air, or the amount of fuel. Make sure manifold heat control valve is free. This can be done by looking at the impression on bowl cover gasket. What more could you ask for? Quick test to see if the accelerator pump is working. Maximum float buoyancy is generally accomplished when the float pontoons are at a 90-degree angle to the fuel valve. 57-65 WCFB 1 x 4 carb - Cover only no spring or spring plate CUD3741 $ 4.99 Gasket - Base WCFB 4GC G402 $ 4.95 Flange Gasket G1164 $ 4.95 WCFB Air Cleaner Gasket . At idle you are at maximum vacuum which makes the metering rods drop down into the main jets. Includes theory, diagrams, detailed specifications, tune-up data and complete overhaul procedures. They need to be centered in the bowl.Fuel could be leaking around the needle & seat. Did the old gasket get removed? Procedure is as follows: with the throttle lever set screw backed out and throttle valves seated in bores of carburetor, press down on vacumeter link (D) until metering rods bottom at (E). However, it is very similar and I found it very useful. Carter used metering rods with a single step, 2-step, 3-step, and 4-step. This eliminates any bog or hesitation when acceleration. They are not meant to fill the hole, only to restrict it. This allows air instead of fuel to be drawn off the pump jets. Carter WCFB 4 Barrel Adjust Float Mikes Carburetor 21.4K subscribers 5.5K views 4 years ago https://www.carburetor-parts.com is providing this video about adjusting the float level and. To correct, remove carburetor and tighten throttle lever by either peening end of shaft over, or soldering end of shaft to throttle lever. The all-aluminum AFB (Aluminum Four Barrel) was a big innovation in 1957, and lives on today under the Edelbrock name. With choke valve held tightly closed, take slack out of linkage and tighten clamp screw on choke lever. features a Carter carburetor identification page and a function that allows you to conduct a search by entering an identification number Factory Carter AFB CFM Ratings Chart Rebuild pics The April 15th, 2019 - The carbs with 1 1 4 venturies and 1 7 16 primary bores and 1 11 16 Back out throttle screw so that the throttle valve close completly. Place universal pump travel gauge T109-117S (if you happen to have one as they are not available) inverted on edge of dust cover boss of bowl cover. As the accelerator is released and the primary throttle plates are closed to the idle position, the upward movement of the pump plunger and attached spring bracket exerts tension on the spring and tends to stabilize the float in a level position. If not then clean it and try again. Fuel enters the primary side of the carburetor through a strainer screen at the fuel inlet and is directed to the primary needle valve and . Once engine speed gets high enough, the carburetor vacuum is strong enough to pull fuel through the main jet and the accelerator pump circuit is no longer used. Both valves should be closed. Ethanol gas does not have much if any lubrication. Make sure the air horn contacts the inner wall of the bowl. When the engine gets hot and then is shut off, gas can sometimes overheat and then boil. You will need to check your motors manual for the spec, but around 4 or 5 should be plenty. William C. Carter was born in Union City Tennessee in 1884. Carter WCFB Carburetor E-Manual Download eWCFB, The file is in PDF format, you can download and save/print a copy, FREE to our customers that buy a rebuild kit. Can't find the answer you're looking for. The high speed air bleed and the secondary bleed tube also acts as an anti-percolator. Fast, secure e-book download. Reinstall carburetor, align and readjust inter connecting rod to manufacturers specifications. Float drop not set, or fuel pump pressure too low. Shorter and smaller overall than the 4GC Rochester, the WCFB was the right choice for dual-quads on a compact . Carter WCFB Carburetor Catalog Free WCFB Carburetor Manuals These manuals contain specifications, parts lists and instructions.The manuals can also be used to help identify those carburetors without tags. During high speed operation a vacuum exists at the pump jets. The single step rods were used on some of the price leader carburetors (i.e. Adjust by bending unloader lip on throttle shaft lever. This check prevents excessive pressure in the discharge passage during acceleration. Product information . With bowl cover assembly inverted and float resting on pin in seated needle, and with gasket removed, the distance from the bowl cover to the top of float should be 7/64. With choke valve tightly closed, tighten fast idle adjusting screw (K) (on high step of cam) until there is the clearance as listed on carburetor specification page between throttle valve and bore of carburetor, side opposite idle port. While holding the parts as indicated above, rotate the metering rod arm B until the finger on the arm at D contacts the lug on the vacuum piston link C. Primary & secondary float will probably have different measurements. Fuel is puffing out nozzles on primary circuit at idle on primary carb of a dual carb set carbs were just rebuilt what is the cause. The Carter WCFB and AFB designs fit easily beneath the low profile C1 and C2 hoods. cm448. Can't find the answer you're looking for? Share. Refer to the Adjustment Data Table for adjustment dimensions. 5:04. This spring is a bit complicated so this video will be very helpful when you change your spring.Find this WCFB spring here: https://www.carburetor-parts.com/wcfb-66d400.htmlFind WCFB parts here:https://www.carburetor-parts.com/wcfb-partscontents:00:0000:42 removing fast idle cam assembly00:56 taking the assembly apart piece by piece01:07 removing the old spring01:22 installing spring02:15 which direction does the pieces go?02:38 assembling the pieces03:16 installing the cam assembly onto the carburetor With engine running, check for an air leak at front left corner of carburetor between throttle body and bowl by squirting carb cleaner at this point. Enter Carb Number. The balance passage also tends to prevent flooding in the event one of the needles should temporarily become stuck open by maintaining equal fuel level between the two float chambers. Most of the single step rods were steel. cm448: Ebook carburetor service manual - 341 pages, 272 MBytes, pdf format. Seat the intake check by tapping lightly in the hole to form a good seal. Place the choke housing toward the left and remove upper right main body to throttle body screw. If the fuel bowl is not filling up enough to fill the pump well, then look at a sticking float needle. You may even have to resort to finding a used WCFB carburetor. Hold air horn upside down with floats in place and gasket removed. Gasket removed as shown A. Please complete the fields below to send your friend a link to this product. Rotate throttle stop screw E until engine idle at approx 500 RPM. Be careful when removing the top of the carburetor that you don't force things and break the piston lever. Notice holes from which linkage rods are removed so they can Carter 2 Barrel BBD Adjustments Mikes Carburetor 21.5K subscribers Subscribe 7.9K views 1 year ago In this video we are going to show you how to do the various adjustments on both the Air. When the piston is frozen you may have to drill a small hole in the bottom of the float bowl, just under the piston and hammer it out. Test the fuel pump to be sure it isnt putting out too much pressure. Fig. Holding the rods down and seated in the bottom (J), revolve metering rod arm until finger on arm contacts lip (K) of vacumeter link. There may be a blockage in the accelerator pump circuit which would also make it hard to pump.What is the carburetor number so we can make sure you have the correct pump?Polish the pump well with crocus cloth. Adjust by bending throttle connector rod at deepest angle as shown. Though fuel float bowl full, cant get gas into the accelerator pump chamber of the carb. The accelerator pump circuit resides on the primary side of. Piston force is too much for linkage. Check any vents to make sure they are open. Hold throttle valve wide open and close choke valve as far as possible without forcing. It needs to go up and down easily.Is there aspringunder the power piston?Are the venturi cluster gaskets sitting flat and not curled over? Check to see that slots in air cleaner gasket line up with vent tubes and do not rotate gasket during installation of air cleaner. Once you get the piston out, clean, Carter WCFB Vacuum Piston the cylinder so that the piston move very free up and down. All These Part Numbers Interchange Into Our Part No. Ultra-Sonic Cleaning3. If the secondary throttle plate is staying open, then check the primary shaft dog and spring. 1956 Chevrolet Corvette & Super Power Kit Engine Idle Speed, Idle Mixture and Throttle Linkage Adjustment Procedure. There should be a retainer keeping the check ball in place. Because the float is maintained in a level position, needle valve bounce is minimized and excess fuel entry into the bowl is prevented. With mineral spirits in the float bowl, Raise the pump. Can't find the answer you're looking for? Each size must be used in its own location. The piston is brass and can be damaged very easily. Be careful removing the intake check retainer. Any pressure put on the needle will damage it. 2: Carter AFB idle mixture and speed adjustment screws. The ends of the connector rod should point to the throttle arm side. 1957 Desoto Adventurer Loose Throttle Lever Rear Carburetor. In this video I show you how to replace the fast idle spring on the WCFB carburetor. You are flooding (getting too much gas in the float bowl), caused by these types of problems. 41-98N Carter 2366S Carter 2505S Carter 2555S Carter 2655S Carter 2669S. Watch this. Pulloffs : CUFWCFB2 $ 0 . The mixture screw may be bent, or damaged. Float adjusted wrong check float level.Float leaking heat up some water and immerse the float. As the spring fatigues, the air valve will open too soon, creating an instantaneous lean condition, and a bog. If hard starting still exists change the choke setting to one point lean. Take the top off and put the pump in the well all the way to the bottom. Carter WCFB Rebuild Kit Selection Carter WCFB Build Sheets Carter WCFB Adjustments Carter WCFB 4 Barrel Carburetor Float System Carter WCFB Accelerator Pump BY CARB TYPE GENERAL TROUBLESHOOTING FAQs INJECTORS PURCHASE PARTS MANUALS BLOG Each float on the float assembly should be at the same height and centered so that they dont rub the side of the float bowl. The accelerator pump is used to provide an extra squirt of fuel when you step on the gas. Be sure these ports are clear. This is an electronic rebuild manual, no physical copy will be provided. Measure from toe B to air horn. Carter WCFB Metering Rods 4,292 views Jul 15, 2018 28 Dislike Share Save Mikes Carburetor 18.7K subscribers https://www.carburetor-part.com is providing this video about the Carter WCFB 4. A balance passage connects the primary and secondary float chambers to provide fuel level control when the vehicle is accelerating, stopping, or rounding curves. Anti-Rust "Dichromate" Finish**4. If not, then find the check ball and make sure it is loose. Gasket removed. Carter WCFB 4 Barrel Accelerator Pump Circuit 3,951 views Jul 13, 2018 33 Dislike Share Mikes Carburetor 20K subscribers https://www.carburetor-parts.com is providing this video about how the. Back out the throttle lever set screw (idle screw) to allow throttle valves to seat in the bores of the carburetor. The item you are trying to purchase is currently out of stock.Please enter your name, email, and phone number below. Fig. There should now be .018 .023 clearance between throttle valve and bore of carburetor (side opposite idle port). It needs about 4 lbs of pressure. If it is, tap gently with a hammer and the same brass drift punch to seat it, or replace the check weight. Blow through the intake check passage to be sure the passage is open. These manuals contain specifications, parts lists and instructions.The manuals can also be used to help identify those carburetors without tags. The idle mixture screws adjust the amount of air/fuel mixture that goes up to the venturi at idle. Back off the idle screw so that the throttle plates close completely. You should feel some pressure and fluid should not be bypassing the check needle. The balance passage also tends to prevent flooding in the event one of the needles should temporarily become stuck open by maintaining equal fuel level between the two float chambers. Some have a coating to give it a better shelf life. Blowing out passages will not get them clean enough. You need to run wire down all small passages. Find many great new & used options and get the best deals for 19571958 Plymouth Fury Carter WCFB Carburetor *Remanufactured at the best online prices at eBay! Measure float height as illustrated above. They work fine when I push hard down on the piston. Buy REMANUFACTURED CARTER WCFB CARBURETOR 3696S For 1958-1965 Chevrolet Corvette 327 348: Carburetors . 3: Holley 4150 idle mixture and speed adjustment screws. One caveatits my impression that the float bowl is full because when I disconnect the fuel supply line from fuel pump (to card), it has pressure on the line. Turn knurled nut of gauge until finger on gauge just touches top of plunger shaft (A).