The Ultimate Edelbrock Carburetor Tuning Guide

[@Compcams1976]

Great video! Very informative!

[@65Bogie]

I always thought my car ran pretty good and then I stumbled upon this video and realize that my vacuum advance was on the wrong port, what a difference thank you very much.

[@MuscleCarSolutions]

Nice! Glad it helped. Tuning is a process. Keep working the process and it’s always amazing how good an old carburetor will run.

[@skipthompson288]

This is by far the best explanation I've seen on how to adjust an eddy carb. Thank you!!!

[@teddybertgarage4119]

You bet, very useful, thanks for chairing 👍🏻

[@Squares.SSs.and.Bowties]

Super helpful video! You made absolute sense out of the jet and needle chart which confused me until I saw your video. THANK YOU!!

[@Daniel-oy4gu]

I love how nice and smooth edelbrocks operate. We didn’t run them much growing up but when a edelbrock is setup right it’s hard to beat in a daily driver.

[@happysailor9858]

Man...THANKS!!!! You have delivered a super informative well filmed session again. I've the way you explain these things.

[@dukebacher1216]

Sir, First off, thank you for taking the time to help others... We appreciate you sharing your knowledge and experience. I have a 1992 Dodge D250 pickup w/360 (LA, not magnum) engine. It originally came with TBI, and ran pretty well until one day Pfffft. No power to coil or EFI. Literally replaced everything including the computer twice, still nothing. I purchased one of the Jegs HEI distributors (to fit a Dodge), an Edelbrock Performer intake, and at first a Holley 1460 Carb. Holly just pumped gas into the cylinders, and it chugged. Never could make it run right... I am using the stock in-tank fuel pump, going through a filter, a bypass regulator (5psi) , another filter, and then one of those "dial-style" deadhead regulators (just to be sure) before the carb. A buddy gave me a Carter/Edelbrock 9635S 4bbl, (600cfm) which I promptly put a kit into, and the truck is extremely happy. I did have to remove the vacuum advance off the dist. because it would hit the intake or the firewall. I "locked down" the timing slider inside the dist, but it still has centrifugal advance intact. With the Eddy/Carter carb, I can get a really nice idle, but it's a little too low (little under 500 RPM). If I attempt to raise it, it suddenly starts sputtering like it's running on about 4-5 cyl. Same thing happens if you lightly rest your foot on the gas pedal. just a little more throttle, and it's back to smooth, and accelerates quickly. Likewise if slowing down, slight pedal pressure (or being between 550-850 RPM) causes this sputtering miss, then it gets down into the idle circuit and smoothes out, but at really low RPM's. The engine is bone stock, with 160,000 miles, Automatic trans, and runs like a scared rabbit with the Edelbrock 4bbl, except for that blasted stutter just above idle. If I could just get it to idle up a little more and to stop that stuttering, It would be running perfect. Am I going to have to find a way to re-install the vacuum advance, or is there something that I am missing? Going down the highway, it purrs... and is 3-4 times more responsive now, than it ever was when it was TBI. Gonna need to do some mods to get my speedometer and overdrive to work again, as they were controlled by the ECU, but that sputtering drives me nuts! Thoughts?

[@dukebacher1216]

@@MuscleCarSolutions Yes, I did use an Edelbrock kit on it. Strange thing, last night I was going to visit a friend in a rural area... when I got onto his road (straight and flat) I put all 270 foot pounds into the pedal and let 'er howl up to about 80-ish MPH (according to phone app) and it now idles at about 750-800 and no sputter! I will have to figure out a way to make the vacuum advance fit in the limited space I have. I figured the mechanical advance would be ok, but if the vacuum will make a difference... I'll massage the firewall a bit.

[@dukebacher1216]

Latest update: truck still runs perfect, and am getting 12mpg (used to get 8...) now! I've decided I'm not touching a thing on it. (except to add an overdrive enable switch)

[@MuscleCarSolutions]

Nice! Well glad it’s running well. Keep those filters clean and you’ll get lots of good miles on it!

[@ianfurqueron5850]

Thanks for a video. I have a Triumph TR8 with an Edelbrock carb (replacing the OEM cross-ram dual Zenith Strombergs). My carb experience is with other British cars with SU and Zenith Strombergs, and despite dreaming of muscle cars in my youth, this is my first car with an American style 4 bbl. I have been struggling with the car since I bought it last year. I came with no choke installed (manual linkage on the carb, but no cable installed), so cold starts have been a SOB. Once it does start, it runs pretty good, although it run super-lean during cruising. The previous owner installed a AFR gauge which is show the rating well in the 16:1 range (or higher) at speed. The temp gauge will also creep up almost to the point of over-heating. Oddly enough, in stop and go traffic with the engine idling, it richens up (13:1 or so) and the temp gauge is perfectly normal. While watching the video, I paused it and went to look at the vacuum ports. Passenger side - capped. Driver side - open (with the vacuum hose to the distributor disconnected. The large center port - also open. Rear port - plugged (the power brakes are connected to a port on the manifold). Something tells me that completely open center port would represent a large vacuum leak? I know from my years fiddling with SUs and Z-Ss, vacuum leaks are the bane of carburetors. I swapped the distributor line to the passenger side port, moved the small cap and capped the large port. I bought a tuning kit, but now I'm wondering if I really needed it... unfortunately, my interior is apart (fixing more previous owner "mods"), so it'll be a day or so before I can start the car and see if the capped ports makes a difference. I wonder if a phenolic plate between the carb and the manifold might help, but unfortunately the space under the hood of a TR8 is tight.

[@MuscleCarSolutions]

You’ve made the right choices and corrected some horrible issues with the vacuum leak in that PCV port up front! Yes, you absolutely need the tuning kit. You have a great advantage there with the AFR to help you tune once you get ready. Yes a block for the heat transfer is important. There is a link in the video description of the narrowest spacer that Edelbrock makes. If you can use it, anything helps!

[@ianfurqueron5850]

Thanks, I'll take a look at the spacer. I also need to check the timing and advance are correct. It's funny - a common saying from working on old British (and Swedish) cars is "90% of carburetor problems are ignition related." Especially since many of these cars are still running points distributors.

[@MuscleCarSolutions]

@@ianfurqueron5850 that’s a statement that proves itself true over and over again! Good luck, and if you run into any issues don’t hesitate to let me know. Always happy to help if I can.

[@tomnekuda3818]

The AFB is the easiest carb to tune I've ever had in terms of an American carb. With their Strip Kit and the charts it is super simple. The only carb I've ever found that is easier to dial in are Webers. I had 42DCOE side drafts on a Chevy I had and, with beer in hand, I found them to be super.

[@bobjackson4171]

Fantastic! Well explained, at a 5th grader level. I wish other folks making vids like this were such good teachers.

[@MuscleCarSolutions]

@@bobjackson4171 well I mean I wasn’t trying to act like anyone watching is a fifth grader. 😂 But I’m glad you liked the video. I’ve got TONS more on Edelbrock carburetors. 👍

[@bobjackson4171]

@@MuscleCarSolutions Lol! Maybe you are more intuitive when making your vids. If the goal is sharing knowledge, then you certainly “get it” sir. I liked, but did forgot to subscribe. I will go do so now! : ) I plan to watch your other vids as well. Thanks for expanding my knowledge and capabilities that will come from it!

[@MuscleCarSolutions]

@@bobjackson4171 that was the whole reason why I started uploading videos. I get a ton of satisfaction when I can help folks. Don’t hesitate to ask any questions along the way. Always happy to help if I can.

[@bobjackson4171]

@@MuscleCarSolutions Thank you! I might take you up on your offer as I go. Thanks in advance!

[@cbobmonster]

Dude, you are freaking amazing and knowledgeable. Great video I sent you a common earlier about stumbling and backfiring on acceleration and it just started happening Dodge 318.

[@mkhy3565]

Thank you. Not sure why Edelbrock stopped putting this tuning chart in the installation manual. It was frustrating just finding it on their website. Need to use a PC, not a phone. This solves alot of issues and shame on Edelbrock for removing this out of their manual. Thanks for the video

[@jondough4116]

Bought mine at summit racing and I got a bunch of Manuels 2yrsvback

[@trifivegarage8683]

Thanks this video has some very good info. I found lowering the fuel pressure to 3lbs. Helped the hot restart issue as well. Doesn't seem to creep as far up after shut down. The ethanol fuel is causing a lot of problems. For those of us running carbs these days.

[@trifivegarage8683]

@@MuscleCarSolutions OK.. I think I will give that a try if I continue to have heat soak problems. Summer is coming and it gets pretty hot here in florida. I'm running the shorter edelbrock spacer 3/8" for the EPS manifold. I have plenty of hood clearance still. Thanks.

[@bryanroupe8646]

A 1 inch spacer should help. I run them on everything.

[@c.pc.5805]

Sir I love the idea of 2 fuel filters this way everything is protected.

[@harvestblades]

Especially for those of us running original gas tanks on forty year old vehicles.

[@crash1769]

very informative. I finally understand in plain english the tuning chart. I have had number of people explain this to me but couldn't understand it until now. thanks Muscle car solutions.

[@MuscleCarSolutions]

Good deal! I’m glad it was well received. I’ve worked on these carbs since I bought my first one in 1989. I still use that chart every single time I tune one. Extremely valuable!

[@dbriggs1689]

Fantastic video thanks for the advice. Im starting this journey on a 75 f100 with a mild cam 460. So far ive determined its an old edelbrock 600cfm but i got ignition maintenance to get sorted out first.

[@MuscleCarSolutions]

Yup. If you get the supporting systems right first (ignition and fuel supply), tuning becomes very easy. Good luck! Don’t hesitate to ask any questions along the way. Happy to help where o can.

[@dbriggs1689]

@@MuscleCarSolutions Thank you.

[@rogjackson]

Stock 1413 (800cfm) on 454 BBC mild cam street car with a T350 automatic transmission. Incoming fuel pressure is 6.5 ish. Ran perfectly for last 5 years accross all throttle positions/weather conditions. Recently, (warming in Northern CA) I get a hesitation from a standing stop to full power (iow punching off the line), but it does go for just a second before the hesitation. Then after the hesitation, everything is fine. From cruise to full throttle no problem. So it's just a hesitation from standing stop to full power, but the hesitation doesn't hit until about a second off the line. Carb looks clean generally and I've never adjusted a thing because it has worked perfectly up to now. Thoughts? Educated guess? I appreciate anyone's input. Cool video!!

[@MuscleCarSolutions]

Ah these conversations always hurt my feelings. 😂 Imagine how much better it will run when you tune it! What’s your engine vacuum at idle? Match the step up spring to it. Then you can adjust from there to remove any hesitation. What is your initial timing set to? When does fill advance come on and what is it? The pressure is on the high side. Just be aware of that if you start having issues. I’d start there and you can work through the tuning process to really get it dialed in. You’ll be surprised what you put up with as “normal” once it’s been tuned for your application.

[@denisonjesse]

I installed edelbrock wood spacer and fuel pressure regulator like the video suggested. Now my chevelle runs better. Great video !!

[@MuscleCarSolutions]

Nice! Good work!

[@rumbador]

I’m about to install a 1406 carburetor to a stock 327 engine hope don’t run into a lot of trouble. Great video will help me a lot

[@rumbador]

Definitely will take your advice about putting two filter. Thank you

[@rumbador]

Bone Head can you recommend me one in particular

[@guillermocastillo3833]

This was a great, informative video. Thanks!

[@MuscleCarSolutions]

I’m glad you liked it. I’ve also broken down each topic with a separate video of you want more info. They’re all in my Edelbrock Carb Tech playlist.

[@danielmather8037]

Thank you for your amazing content!!!

[@chuckchrystak4397]

Great video, nice and straight forward!

[@MuscleCarSolutions]

Thanks!

[@kevinsweetwater7293]

This video is awesome! Thanks

[@ArnCital]

There is a lack of information on A/F ratios vs power and fuel economy with regards to stressing the engine (knock, ping, burned valves). For example what is the best A/F for fuel economy while cruising without leaning out the engine too much? My truck is a 1985 F-250 HD (5,900# certified scales) with a fresh 460, T-19 4-speed, 4x4, high boy, 9:1 c.r. with forged pistons, mild cam, stock heads/exhaust. Dyno at 4,200' is 246 HP/4,200 rpm at the rear wheels (Dana 70 rear end) and max torque at 2,500 cruising rpm. Best number for fuel economy I could find was 15.4 A/F. I leaned out a 1405 to one stage leaner (at 4,000' elevation) and the truck will get up to 11 mpg and runs strong. That said, 200 miles on fresh plugs shows the porcelain insulator to be a clean white and not a light grey or brown that is optimum; the ground electrode has a slight buildup of deposits. There is NO ping or knock so I am good there. My point is that it is a good idea to read the spark plugs while tuning. I may be just slightly too lean and will experiment with rods and jets. My AutoMeter A/F shows 15.4 A/F when cruising and above to 16 with slightly more power for passing, etc. WOT power and idle is 12-13. Had I installed stainless steel or stellite-faced exhaust valves then I would not worry too much about being slightly lean. If you cannot measure it then you cannot troubleshoot it, you can only guess and I hate guessing. I am still looking for a good book or read on A/F tuning.

[@ArnCital]

@@MuscleCarSolutions Thanks for the rapid response. I have planned on lowering the A/F ratio. Nowhere on the internet or library have I found studies of varying A/F ratios and effects on driveability, engine load, engine damage, and so on. I am an industrial engineer and dealt with numbers and not opinions. That is why I monitor the A/F and vacuum along with load and rpm. Too expensive to add a gear. BTW, the engine is built as strong as I could with Eagle rods and Autotec forged pistons. It is capable of handling 550 HP and I have about 300 HP at the flywheel. Timing is 8 deg BTDC on a stock dizzy. After observing retaliative coarse A/F changes with the EDDY then I am now considering EFI because I can fine tune the engine fuel parameters.

[@garlandjones7709]

What an engine desires for a/f is not a static/constant number. Each engine will like a different number. Anyone can get you ballpark, but in the end, it's similar to timing There's not a magic rule outside of experimenting. Called "tuning"

[@shellback2002]

Sir, I found your video along with the Edelbrock manual extremely useful. I have a '78 Ford F 150 400m engine and C6 transmission. I just had the heads properly freshened with hard seats, guides etc. I updated the engine with a Comp Cams RV style cam and timing set, Pertonix distributor, Edelbrock 3771 4bbl manifold and a 1406 carburetor. Once the vehicle was running, Initial curb idle timing set at 12* BTDC without the vacuum and 36* BTDC with vacuum at 32-3400 RPM, idle mixture set for max vacuum I have encountered 2 issues. There was a soft lean misfire at light to medium throttle . I have solved that satisfactorily by increasing the metering rod 1 step straight North on the calibration chart from the stock 7547 to a 7347. The unresolved issue is a light misfire during the transition from closed throttle to about 1/3 throttle. I find that little burble irritating particularly at cruising speeds. Thanks for your time

[@shellback2002]

Bones’ Thank you for your prompt reply. I do not think the misfire is back through the carburetor, it doesn’t feel acute enough for that. think your suggestion of timing and hose routing is an excellent next step. Currently The vacuum source for the vacuum pod is from a true manifold vacuum source through a thermostatic valve to the pod as illustrated in the 2 photos. The plugged hose went to the plugged nipple on the carb base.It goes to a vacuum router at the rear of the engine for EGR and EVAP that I found had a significant vacuum leak. image2.jpeg image1.jpeg The vehicle has passed emissions inspection so I can move things around as I please. Would you suggest vacuum to the pod directly from the manifold vacuum port on the carb base. Unfortunately this will be the only adjustment I can make for the next 2 months. My son the owner is a Chief Engineer on a container ship and goes back to sea on Friday. The truck will drive N 130 mi and then sit in the ship yard for 2 months. I’m a retired European automobile mechanic and shop owner. This has been a fun project for the Chief Mechanic and the Chief Engineer. I do so love EFI! The cars I worked on sold their last carbureted vehicle in the US in 1972 right at the end of my apprenticeship.....lol. Thanks again for your knowledgeable input. I’ll keep you posted as progress is made. Disseminated from Zubenelgenubi

[@shellback2002]

I guess the photos didn’t go through. The vacuum source is a fitting on the #5 intake runner.

[@shellback2002]

@@MuscleCarSolutions Excellent suggestion! Thank you. I have now put the Vac pod hose on the correct nipple on the carb. It now runs significantly better. I think I will go back to the original 7547 rods and give that a try when my son returns from sea and brings the truck back. Thank you again for your on point and wise counsel. If you ever deal with SU carburetors give be a ping. That was my world back in the day. Cheers Bo

[@shellback2002]

Bone Head, I think I will purchase one of your suggested A/F ratio measurement systems to aid me in dialing in my sons truck when he returns. I think I can also figure out a way to use it with my boat engine which is a Chrysler Marine 318 with a 1409 carburetor. Once again thank you for your wise council.

[@driftking4134]

Hey bro thanks alot amazing explanation, i appreciate...

[@Joeshmoe.x]

Great video! Thank you

[@michaelnowak3570]

I am trying to cure a slight stumble off idle. Open it runs really well. Idle can be slightly rough after I adjusted mixture so that is better. Timing is on. The just off idle is not smooth into power.

[@MuscleCarSolutions]

Have you made any adjustments to the accelerator pump to verify if you need more fuel or less?

[@laokartoon7300]

i learned a lot today. thank you sir.

[@MuscleCarSolutions]

Nice! Thank you! I have since broken down this video into a few others to expand on the individual segments of it. If you want a little more info, they are all in my Edelbrock carb tech playlist.

[@laokartoon7300]

@@MuscleCarSolutions ok, thank you.

[@waynep343]

put a 10 micron fuel filter before the mechanical fuel pump to keep sediment out of the fuel pump check valves.. 1984 corvette fuel filters are 10 micron.. when sediment gets in the check valves the fuel pressure held by the pump in the line to the carb is reduced. this reduction in fuel pressure allows the fuel in the line to the carb to boil.. the expanding vapor pushes liquid fuel backward thru the fuel pump.. .leaving the carb low on fuel. this reduces fuel boil over and hard to start engines because they are flooded.. when the sediment in the fuel pump gets thru to the needle and seat.. it can when the fuel level is reduces allow fuel vapor to expand and overflow the carb.. if you have an off idle stumble with an edelbrock.. cold engine count the fractions of turns to lightly seat the idle mixture screws.. take them out.. with a can of carb cleaner.. blast a 1 second spray down the idle mixture screw hole... 1 SECOND.. followed instantly by a blast of compressed air. do this 2 or 3 times for each idle mixture screw hole.. this blows sediment out of the idle feed restriction and the idle air bleed. in the primary booster assembly. if you have flat spots and you are running an engine over 360 cubic inches.. and especially over 400 cubic inches.. you may have to use a 61 to 80 drill set and one size at a time drill the idle feed restrictions in the side of the primary booster assemblies. its behind the idle air bleed on the side. you want to take the top off the carb.. then take the primary boosters out.. 2 screws. figure out what size the second part of the passage is. go up 0.001 .. reassemble and test drive .. you will need to readjust the idle mixture. the idle speed then test drive. if you get a flat spot at around 1000 or 200 above base idle.. or up to about 2200 RPMs before the primary circuits take over completely.. keep drilling 0.001 at a time. look up Low speed circuit.. look up idle transition circuit.. look up economizer circuit. edelbrock and holley removed this info from the carb manuals to allow the carb tuners something to work with. .

[@coachk7674]

great stuff, I have a new 1406 Edelbrock on a 72 K1500V8, 350, 5.7 etc. manual choke cable and have recently moved from sea level to above 9200 feet. today for the first time it would not start and drained a battery trying. before I start over, my question is: does the high altitude affect the cold starts?

[@MuscleCarSolutions]

It affects every operation on a carb. Absolutely. Higher elevation means less oxygen. You’ve got some tuning to do!

[@tylerhutchinson3646]

Hey I just put my create 5.8 in with a 1406 Edelbrock. Now I know it's really set for economy. But I ordered rods and springs. Your videos have show alot. But I'm getting a feel for my next step. I thought I had it tuned pretty good but iv got this stumble in each drive and idle that I'm trying to work out.

[@MuscleCarSolutions]

Yup. Keep tuning. You’ve got the tuning kit and that’s a great start. Make some changes to the accelerator pump. I did a video on that. Adjust fuel pressure. Did a video on that as well. Keep working with your timing as you make adjustments that get you good results. You’re a little limited with the older performer series carb on the secondary side, but you still have lots of tuning points to get it dialed in. As long as the cam profile isn’t too wild, and what you’re using it for, you’re on the right track.

[@DavidPerez-cd9tu]

Great info thanks

[@dizzyphil1]

Perfect info

[@thedobermangang3503]

i got 1990 k5 blazer 5.7 had it rebuild with a few up grades everything is pretty mush stock i up graded the cam to a howard cam rattler lift 225/230 duration 0.50/227/235 centerline 03 i still have the factory swirl port heads i got headers 3' pipes all the way back i up graded my torque converter to 2000 to 2400 stall and 4:10 gears i just put my engine in about a week ago it was a tbi so i converted it to carb...im having problem trying to get it to run right i put a brandnew edelbrock carb 1406 on it..i got 12-887 holley regulator set it to 6 psi i got it to run starts up good but its backfiring and popping out my exhaust ..i have a vacuum port on my regulator but did not hook it up dont no if thats the problem or not..or is the carb to small for my set up...you can smell the burning and the raw gas in park when u accelerate and give it more gas it sound good but at idling its popping and backfiring like someome popping fire crackers..tell me what you think

[@CORNDODGER]

Damn I needed this I just put a 2 inch Spacer on my engine and now it seems to lean out way to much around 4000 rpm and my shit point is at 4500 just ordered a complete kit from speedway

[@sidecarbod1441]

10:10 The tuning chart for the 500 carb has got at least 3 errors in it! If you work out the area of a jet and then the two cross sectional areas of the rods you can work out the flow area for any given combination of jet and rod, you can then compare this to any other combination. I use an XL spreadsheet to work all of this out, it has shown that the percentage figures of change that Edelbrock quote in their chart is sometimes wrong!

[@wesleewilson_]

Great video! I'm reading through the manual and trying to wrap my head around how this carburetor works. Do you have a simple explanation for what components effect which driving conditions? IE: idle mixture screws determine idle afr during idle, but also; primarily jets effect this too? Then when accelerating, springs and metering rods kick in. Then, during wide open throttle, primary, secondary, and idle mixture screws determine afr. Am I correct here? Basically, I'm trying to narrow down what to change by looking at afr during different driving conditions. Also, what is a good afr for each of these stages when shooting for fuel economy?

[@shadvan9494]

I find the Edelbrock carbs tend to be too rich from the factory. my tuning method is to get the engine to operating temperature. set the timing using the total timing method with the vacuum advance disconnected. then get a measurement on vacuum and install the recommended piston spring. I then set the choke to full open so the choke will not affect tuning. the use a AFR gage like you recommended to set the Idle. I like my idle around 14.5:1 for best efficiency and lowest emissions. Then I find a nice flat open stretch of road or freeway with low traffic and cruise at 35-40 mph and take a reading, then 50-60 mph and take a reading, attempting to keep the pedal in the same place to eliminate as much fluctuation as possible. the reading should be pretty close, I use that to set the air fuel ratio for cruise. i like 14.5 to 14:1 the using that same stretch of road, I start with cursing at speed and then roll into the throttle a bit but not opening the secondaries. think of it as passing a car on the freeway. I want to see the AFR gauge drop to around 12.5-13:1 then gradually come back up as the engine increase rpm and vacuum recovers to pull the pistons down. lastly, I use test and tune nights at the drag strip to dial in the secondaries. with all 4 barrels open i want to see my AFR between 12.5-13:1. if there is any bog or hesitation off the line, at this point O increase the size of the squirters or possibly changing the springs. lastly after the car has cooled down to room temp, i set the choke per the factory instruction, and then in winter i fine tune the choke setting to make sure it starts with very little effort on a cold day. I have also found that sometimes you need rods or jets that are not included in the tuning kit. Edelbrock makes a very large assortment of rods and jets, but they are not all included in the tuning kit. I have also found that sometimes i need a summer Tune (leaner) and a winter tune (richer) to make things run right. I just document what i had it at before and then return it to that setting at the end of the season. this same process also works on a Quadrajet, you can still get Performer Q-jet parts from Edelbrock including rods, jets, springs, hanger, etc.

[@MuscleCarSolutions]

Wow. You really like your AFR on the extreme lean side. With todays fuels, I don’t know that I’ve ever met anyone who’s willing to take that chance.

[@car_ventures]

Thanks for putting this together. Struggling to get mine running nice on a 350 sbc. Spent a couple of hours just now. At idle it smells rich, going leaner causes the engine to run rougher / close to stall. Also hesitates momentarily when throttle blipped. Going rich means throttle blip is ok and smooth, but kicks some smoke out and idle smells of unburned fuel. Feel like I've been going around in circles (adjusting idle speed along the way as rpm drops / increases - aiming for 600 / 650 idle rpm in park).

[@car_ventures]

@@MuscleCarSolutions wow thanks for the quick reply! Engine has stock cam, edelbrock performer intake and carb, headers and 2.5" exhaust with X pipe and flowmaster delta 50 mufflers. Adjusted timing a few times, seems to be pretty consistent aka sits at 12°@ idle and 36°@ ~2500rpm. Have only been adjusting the front two mix screws and the idle rpm screw so far to try and get it consistent... i.e aiming for no fuel smell @idle, smooth throttle response and smooth idle. Is it likely the answer lies in rod / jet changes?

[@car_ventures]

@@MuscleCarSolutions The carb is a 1406, so works out to a pretty typical SBC upgrade with the intake and headers. It was fitted to the car before I bought it, so not sure if it's got the stock jets in there. Think I'll grab a kit from Edelbrock with all the rods etc. I'm in England so takes a while to get over here from the U.S. Might do a video of it running with a vacuum gauge on and share it with you for feedback. Carb tuning a V8 is not too common over here :)

[@markusgarvey]

You forgot to mention not only pressure but volume of fuel as well. Especially if you lower your float level. I had an issue where the pressure of the stock mec pump was fine under normal conditions, but there was not enough fuel volume when under WOT. I added a booster pump, or you can just eliminate the mech pump. Personally I like redundant fuel pumps. And you dont need to install a return. This was on a Pontiac 409 w/ 068 tri power cam and Edelbrock 750.

[@MuscleCarSolutions]

Mark Estrada absolutely flow is critical. I mentioned in a recent video that’s why I run Aeromotive pumps, filters and regulators. They flow well across the pressure ranges in all instances. There’s only so much you can put in a 16 minute video. High level basics on this video. Everything in steps.

[@skipthompson288]

hahahaha the 14 people who don't like this can't adjust their holley carb and they just found out how easy an Edelbrock is. LMAO

[@KStewart-th4sk]

@Skip Thompson Up to 36 as of 12/11/2019. Funny, a guy called Bone Head can and they can't. LOL

[@jaoojoao5361]

In my opinion holley gets a better adjustement but really like them both ,edel for the streets holley for the strips

[@DeanBishop-gb9mx]

Great video, I just finished building a first gen 350. I have it in a run stand and as a project want to learn my edelbrock carb and how to make it right. I assure you that you will be hearing from me with questions. Can you tell me the best way to communicate with you. Thank you

[@MuscleCarSolutions]

Best of luck! They’re actually very easy to tune and work on. I’ve got a whole playlist of Edelbrock carburetor content. Just drop any questions in the video you’re watching. If I get the notification, I’ll respond.

[@ericdolby1622]

Wish there was a guide like this for tuning a 1405 on a huge cam Chevy 348

[@kylerrichardson4858]

Resurrecting this masterpiece. Ive assembled a new 400 with higher compression and a mild (276) cam, as well as this AVS2 carb. What would you recommend as a starting point to ensure I can fire up and break in my cam right away and not wipe anything dry trying to fire it up the first time? *edited for typo

[@rustyridesgarage672]

I live in Loveland Colorado whereabouts should my Jets be setted for a 600 CFM Edelbrock running into tunnel ram running into stock 350

[@cbobmonster]

I know this video was a long time ago, but just curious my 318 Dodge under acceleration is sputtering and backfiring once in a while and it just started doing it was wondering if you had any issues excuse me information it’s got an AVS to Edelbrock on it

[@MuscleCarSolutions]

@@cbobmonster don’t know. Could be a number of things. Verify timing and ignition components. Once an engine is under load, that’s when it puts stress on ignition system components. Bad grounds can cause this as well. That’s where I’d start. Then you can start looking at fuel. If it’s a lean condition causing it, it could be fuel filters are clogged or restricted. Fuel pump might not be able to keep up when the fuel demand increases. Garbage blocking secondary jets. Step up springs are incorrect or need a change to a different rate spring. You can also add in potential vacuum leak(s). Start working through and eliminate the possibilities until you find the issue.

[@bdavis12758]

This is a great video. I recently swapped a 06 5.3 in my 1980 k10 which I swapped the fuel injection to a carburetor. I opted for a Holley mid rise intake, edelbrock 1406 carb, and msd 6014(I believe the number is) ignition controller and once I got my batter ground figured out, she fired up no problems.... I’ve yet to adjust it any means being in Kansas I have no idea what the tuning is gonna be..... I’m in Europe on a 9 month rotation and all I read is my carb book so when I get home I can tune with no reference(it’s a small goal I set for myself).... anyways I enjoyed the video. I have a suggestion, maybe tuning idle mixture and determine if you need a new jet. And what is a good baseline for inches of mercury which I believe is 20.5 inches.... I may be wrong but that’s what learning is all about.......

[@bdavis12758]

Bone Head okay I understand. So you could really diagnose jet and rods by dyno, a/f gauge, and driving it.... like I said, I know a little about carbs and trying to learn as much as possible..... For the carb conversion, yes everything is stock.... you’ll need to reroute the vent tube of the driver side head, change the intake of course, and bit an ignition controller..... Holley has a similar setup for the atomic efi which i didn’t want bc it was expensive, and a waste as I’m not trying to go high horsepower.... just a beater with a heater and a little pep in her step....

[@bdavis12758]

Bone Head also, the carb was a reman from edelbrock from jegs.com and only has 3 starts and a 2 minute idle each start bc I don’t have a belt tensioner therefore no belt to spin the water pump and so on.... then left to Europe and have some parts waiting for me if my wife doesn’t sell them 😂

[@bdavis12758]

Bone Head well I had it running just not long enough for the choke to open up so it was a high idle at 1600rpm. I have to adjust the fast idle ad get the idle screws perfect..... I know someone with a similar setup and it’s just awesome. Except he he’s a bigger carb......... I’m pretty sure the 600cfm should be fine on a completely bone stock 5.3.... I’ve seen 750’s on a 305 and other 327’s and they were fine..... if anything, I’ll have to buy a bigger carb.... I want to put a cam from an ls6 with better valves springs bc I love high reving v8’s.... just enough for towing a little and mainly a daily driver.... I’m looking for an nv4500 but people want so much money for that transmission without a bell housing.....

[@reriley2002]

I’m running dual edelbrock Avs 500’s on a pretty stock sbc. I have a stumble right off idle if I nail the throttle. If I roll into the throttle, it burns the tires. The plugs are all nice and tan, msd, vac. Advance distributor, timing set at 10 deg. Btdc. Full advance is 36deg. By 2500 rpm. The chrome headers are turning blue, which would indicate lean to me. Where do I start? I do not have the book as I bought this whole setup used. I am assuming that both carbs. Have the stock jets, springs and rods, but I have not verified that yet. The pump shot linkage on both carbs is set in the center hole. Electric fuel pump, regulator with gauge, 2 fuel filters, and aluminum 1” carb spacers. Running 4psi of fuel pressure.

[@MuscleCarSolutions]

Lots of questions and places you can potentially start. I’d add some more initial timing to start with. It’s time to begin to look at tuning the carbs as well. I wouldn’t rely on the chrome headers being a good indication of a lean condition. In my opinion, the only way I will tune any dual set up is with an AFR. Preferably a dual O2. I know they are very expensive but it’s really the best way to tune those carbs and set timing. I know 30 years ago Dad did it all by ear but there is a wild card in all this - we have horrible fuel today with ethanol. So consider that investment if you plan on keeping that set up.

[@TandD1w]

I was very tempted to get the AV2 carb, until my tuner shop recommended against it for the carb boiling issues. Did some searching and came up with a Edelbrock tech page addressing this. Now you mention it as well. Now, I'm wondering just how big of a problem this is. Maybe this isn't the right choice for my iron manifold application.

[@TandD1w]

The techs argument was the Edelbrock places it’s fuel bowl directly over the carb flange whereas the Holley places it’s bowl off to the side. The Holley has more separation from the flange so there is a longer thermal path and the Holley has more surface area of help remove the heat from the bowls. His argument does seem to have some merit. Personally, I’m liking the carb because I don’t have to dump fuel every time I change a jet and it’s supposed to hold its tune better.

[@therealbadbob2201]

I have a 318 with a torquey cam and magnum 360 heads. I have not been able to get the stumble off idle to go away, but at 2000 rpm if I kick her in the guts she absolutely screams.

[@Jacob-dq4cs]

The real Bad Bob I have the same problem in my big block, she doesn’t like to take off but once you get past 2000 hold on lol

Thanks for the info🙂

[@johnpaniagua3530]

Great video thank you.

[@crazyhorseDOC59]

I'm using anf AFR gauge running a 650 AVS2, in cruise mode running 13.5 throughtout the RPM range up tp 6000, however if I go wide open throttle after about 3000 RPM the AFR goes to 25 or more...way to lean. When I go richer on the primary side it runs 8.0 to 10. without any change at WOT, still runs lean. went richer with the seconday jet...no change in WOT Engine is a SBC 350 has about 3000 miles.

[@MuscleCarSolutions]

How have you adjusted the AVS?

[@crazyhorseDOC59]

@@MuscleCarSolutions currently at 7 for model 1915 on pink spring .104 secondary jets, minus 1/4 turn less tension on the secondary plate.

[@MuscleCarSolutions]

@@crazyhorseDOC59 there we go. Add tension to the AVS. kzbin.info/www/bejne/nqPalJijmtxrnZo

[@crazyhorseDOC59]

@@MuscleCarSolutions that was the only video of yours I had not seen. All your videos are very well done. Great productions. Thank you.

[@MuscleCarSolutions]

@@crazyhorseDOC59 glad they have been helpful! Let me know if that AVS adjustment helped.

[@dirtydan2074]

Thank you!

[@MuscleCarSolutions]

You’re welcome!

[@hanger44smba78]

My truck surges when driving. I'm running a 600 4bbl edelbrock. What do you think it is. It feels like it runs strong then skips on and off running on all 8.

[@tommyyarbery379]

So I have an edlebrok 1404 every since I installed it it's ran like crap. I don't have a rpm gauge (77c10). I've adjusted the air/fuel screws a thousand times but the idle continues to hunt, ive checked timing, vacuum leaks ECT. I've installed the adapter for the 1404 on the intake. All 4 opening on the intake are about a little less than a 1/4 in blocked by the gasket(maybe that's the problem?) I've made it back fire through the carb twice and both times the truck ran fine after words. But after about 30 min it's back to running hunting. I'm at a complete loss on it. The original carb was a quadrajet 600cfm the 1404 edlebrok is 500cfm. Maybe under cfm? I went back and forth between air ratio screws idle screw and timing for around 3 hrs lol all the hoses are in the correct spot and timing is correct according to the air cleaner cover(2° for a 350) also switched it to the second hole down on the acc pump for a bigger pump of gas (which helped steady idle alot) any input is much appreciated (77 c10 350 stock intake edle brok 1404 with adapter plate to intake)

[@tommyyarbery379]

@@MuscleCarSolutions the pressure regulator I have no idea honestly, I added one after the pump before the carb recently, I have not took apart the edlebrok yet and the back fire only happens through the carb if I rev it a couple times while it's surging.

[@tommyyarbery379]

@@MuscleCarSolutions I've set and reset the timing to 2° Everytime I turn my idle up or down

[@tommyyarbery379]

@@MuscleCarSolutions no I never added a pressure regulator, everything on the engine is stock except the 1404. I added a new filter between the carb and the fuel pump when I installed the edlebrok about a month ago. There is another one before the pump that I changed about 6 months ago while I still had the quadrajet on it.

[@tommyyarbery379]

@@MuscleCarSolutions alright alright thank you very much, I'll get back to you as soon as the funds are there for me to buy parts

[@paulsinclair7165]

Thank you.

[@obsessivegarage921]

Hey watch your videos all the time. Love them thank you very much. Quick question, I have a 1406 Elderbrock carb, I was told to tune it using the 1405 chart, possibly on #1 setting or even #2 or #9, which take the .100 jet and .068x.042 rod or .070x.047 rod etc to get better performance out of it for my 70 Nova. (350 5.7 Vortec, high rise intake, long tube headers, roller cam) And the #1468 accelerator pump as well. I'm about to rebuild my elderbrock carburetor soon and I've been reading up and re-watching a lot of your videos. Thx for any tips are help, you're awesome 👌

[@arcorob]

Great video but confused on the front vacuum ports (around 7:30 in the video) . I have a 1966 mustang, Edelbrock Performer Manifold and carb, original style vacuum advance distributor. I was under the impression that the right (drivers side) is what I should use and the left was for type that have egr. Am I wrong? I also notice with a vacuum gauge, left port is Zero unless throttle is applied whereas right port has constant vacuum. HELP ..LOL... I want it to be hooked up correctly. Thanks !!!

[@arcorob]

Bone Head yup I knew that and thanks for straightening this out. But now begs the question of vacuum gage and setting idle air fuel. I have seen you should get max vacuum when setting, then back down 1/2 turn on each side. How do I get max vacuum if it's zero at idle? Use the other side?

[@arcorob]

@@MuscleCarSolutionsYou are awesome...thanks for the quick clear replies !!!

[@Washitguy]

So, because I am dummy... which port to use when using a vacuum gauge? Driver or passenger side?

[@sed6]

@@Washitguy Driver side for running a vacuum gauge.

[@pooroledaddyfishing8132]

Great video, very helpful in understanding the chart. What should the timing be on the 454 I have, the vacuum advance is plugged at the distributor and both caps on the carb

[@pooroledaddyfishing8132]

Bone Head , I think it’s a regular gm distributor when the motor was put in they said I didn’t need the vacuum advance part. Coil pack on top of distributor. I didn’t know if I needed that to be hooked up .

[@jamesmccoy5590]

Do you know what would cause fuel not to go to the carberator with a new edelbrock carburetor and a new fuel pump assembly

[@MuscleCarSolutions]

Difficult to say. Make sure the pump is working. Make sure your filters aren’t clogged. Do you have a vented gas tank cap?

[@chevylandtv670]

Can someone help me out! I have a brand new avs Edlebrock 1406 on a stock 305 with a computer delete my idle n park is high but when n drive it pretty good, also my clothes smell like I been riding a dirt when I stand by the car also I’m seeing smoke come out the carb when I shut the engine off using an aluminum quadrajet spacer this is a brand new Edlebrock carburetor straight out the box any suggestions would help

[@MuscleCarSolutions]

Sounds like you’re into the transfer slots at idle which would cause the rich condition. Keep in mind the 650 is too much carburetor for a stock 305 so you’ll be fighting the rich condition for awhile.

[@marks-yw5ij]

I'm very new to figuring out how to set up/ tune my edelbrock carb. I sont believe me secondaries are opening. When looking down the carb and going from idle to about 5500rpm I dont see them opening. Is this right? How can I fix this ?

[@willemtheron]

If the step-up springs do not fix a hesitation, stumble etc. and you go on to change the metering rods, do I need to go back to the first spring that was in there before I started changing to different springs?

[@MuscleCarSolutions]

That’s the difficulty con tuning by just feel. An AFR would let you know if those changes were effective before you move on to working else. Keep the springs you selected, then make your rod/jet change and see if it gets better.

[@ciaranlowe5547]

Excellent video thank you so much for sharing your knowledge. I have one question, I’ve built a Windsor 351 60 thou over AFR heads and Edlebrook AVS2 800cfm carb and manifold. The engine is not installed yet. Is 800 cfm too big . If it is, can I adjust the carb downwards ?

[@MuscleCarSolutions]

You can’t change the CFM of a carburetor. What is the max rpm on this engine?

[@ciaranlowe5547]

@@MuscleCarSolutions street use only

[@MuscleCarSolutions]

@@ciaranlowe5547 need an rpm. What’s the cam rated for? What range? It’s important.

[@ciaranlowe5547]

@@MuscleCarSolutions 1500 to 5000 rpm range using a Lunati roller cam 112 lobe separation 108 center line rolle rockers 1.6 ratio. Cam part # 20350711. Hope this helps

[@MuscleCarSolutions]

@@ciaranlowe5547 yup. That’s exactly what you need to know. By the math, that engine would need a CFM of around 523.72. If it’s just a street cruiser with a really low rpm range, you’ll have a way easier time tuning with a 650 or 500. That 800 will be an extremely rich running engine that you won’t be able to tune away.

[@maximuswedgie5149]

This is a fantastic video that I’ve been looking for. Tomorrow morning I go pick up my 1408 or 1480? Edelbrock tuning kit. I had no idea where to start now I do thank you very much. I put a new 383 ( with bigger cam and roller set up)in my Mopar and I got a terrible stumble off the line. I can’t even put it in gear unless it’s almost 1200 RPMs at idle without it dying. I will be referring back to your video and I will hope that my kit comes with that book. If not I will download the PDF as you said. Thanks again for the great video sir

[@MuscleCarSolutions]

Well you’ve got some work ahead of you but the good news is with some patience and a little understanding, you’ll be able to get it running and driving much better. Don’t hesitate to ask any questions if you get stuck. Happy to help if I can.

[@MuscleCarSolutions]

I’ve got a ton of Edelbrock carb videos and fuel system set up in a playlist. You might find some of those useful too. Good luck!

[@maximuswedgie5149]

@@MuscleCarSolutions I will definitely check the other videos out👍🏻 thanks for the reply

[@andrewpapke8051]

I am running dual avs 500s on small block ford and tunnel ram. Would love some more info on a side chat.

[@armandomendoza3167]

Will this eddlebrock tuning guide work on a Rochester? I've noticed the the numbers kind of match on jets. Rods I can't remember. It has been years since I worked on a carburetor. I'm thinking of a EFI conversion to a carburetor set up.

[@TheTexasDuke]

Hey so just recently inherited my fathers red 1983 gmc shortbed he’s passed sadly, so I tuned my new carb but ya keeps flooding on just giving it gas and putters out, then I have to wait 30 mins to retry and move it

[@MuscleCarSolutions]

Lots of things to look at. If it’s blowing past the needle and seats then figure out why. Get a pressure regulator and dial the pressure to 6psi or lower. Take the top off the carb and see how much garbage is on there and clean as necessary.

[@davidkeeton6716]

The manual I have with my 1413 800 cfm carb says that the passenger side small port is for emissions controlled engines and the driver side port is for non emissions controlled engines/distributors. Right now I'm actually using the original 1964 point distributor. Should I use the one on the driver side, that I am using?

[@MuscleCarSolutions]

The better question would be how big is the cam profile? Is it stock? Use the timed port. Is it an aggressive long duration cam? Use the full manifold port.

[@erik9685]

I have a Carter AFB 650. It is rather new and has not been used. It has been sitting since October 23. My problem is i just installed a new small block in a 1970 chevelle. And i got the car to run. It takes about a dousen times to turn over before it fires up and runs. There is a POPING noise comming from the exhaust pipe. I believe its comming from thec passenger side pipe. Is that a carburetor issue? How do i handle this issue?Is the poping noise a symptom of the car running rich? I set the timing @ degrees and the total timing is at 32 degrees at 3500 RPM with the vacuum advanced disconnected.

[@stjp6599]

Hello, eddie carb 600 on 72 Dodge Challenger 340. Starts great cold. Idles great when kickdown.Take off get to first light when at temp,always have to give slight bump to pedal to lower idle. Thoughts?

[@MuscleCarSolutions]

Linkage adjustment? Electric choke? Not releasing? Fast idle cam sticking?

[@craigheidelberger3325]

At high RPM or WOT she cuts out. What are the things I should look for? It has 6psi and I can blow right thru the fuel filter. Any info would be great and thanks for the video.

[@craigheidelberger3325]

@@MuscleCarSolutions O man, I left out a tad bit of info. Sbc 350 bored .060, 650 Edelbrock choke plate removed. (I live in Texas), 280 Comp cam, Weiand Stealth intake (dual plane) hooker headers, cast iron Summit racing heads. ( like a vortex according to my machinist) 700R4 tranny, 2800 stall, 4:10 posi,tires are 28" from bottom to top. HEI ignition with a "high output module". I had it dyno tuned about a year and a half ago. The (what I think) starving for fuel situation started about 3 weeks ago. Also pardon some of my ignorance I'm an automotive weekend warrior. 😆 I appreciate your time.

[@craigheidelberger3325]

@@MuscleCarSolutions truck will sit a maximum of 2 weeks at a time every now and then. I use 93 octane and to be honest I don't know what percentage of ethanol is in the gas we have here in the D/FW area. But I have not tinkered with the truck since dyno tune. I checked to make sure distributor is still tight and it is. I did notice right after the tune truck would start with no pumping of gas. Now...... After truck sits for about 2 days I have to pump gas 2 or 3 times to start it. (For about the last 3 month's or so)

[@craigheidelberger3325]

@@MuscleCarSolutions I am leaning toward ethanol contamination. I will replace the fuel filter (which is before the manual pump) and see what happens from that point. It's wet right now so it will be a day or 2 before I can get it on the road for a test. What would you consider sitting a long time? And thanks for your help once again.

[@craigheidelberger3325]

Just replaced the fuel filter and what difference. I really appreciate your advice. Its the simple things that get overlooked. I was able to blow right thru the old filter but like you said it must lose fuel pressure at wide open throttle. Now........ we need to discuss in the future about making her go faster. Any advice would be great. Looking to replace cast heads with aluminum heads just need the best bang for the buck. Unfortunately I have dished pistons and cant afford to replace lower half (pistons) right now.

[@craigheidelberger3325]

Well.......... guess what? The hesitation came back (intermittently) at wide open throttle. This weekend I'm going to blow out the line toward the gas tank with compressed air with the hopes that maybe the inlet line which has a tiny little net is slightly clogged. At the carb I'm reading 6psi but who knows at wot. If I replace the fuel pump, the only hp ones seem to be 8 psi at Summit Racing. What are the consequences of running 2 extra psi? I guess I'm automatically leaning to toward a delivery starvation issue.......

[@DesertRatFabrication]

And also what do you mean about the set-up spring to control the transition between cruise and power, thanks

[@dalejrfan820002000]

I have a question about the secondary. ? Ok I how a after market throttle cable bracket. For the gas pedal and the kick down cable. Ok Trying to get it setup Wright is a pain. Because I don't think the secondary are opening. ?

[@MuscleCarSolutions]

Secondaries are vacuum operated. The throttle linkage will open Tuesday primary side and the secondaries on the bottom side of the carburetor. The top weighted valve is controlled by the load on the engine. When there is enough load and the vacuum drops, the valve will open.

[@dalejrfan820002000]

@@MuscleCarSolutions Ok so if I'm driving 55 mph and floor it should they open up? The carb IS new. I'm trying to figure this out 😂😂😂

[@MuscleCarSolutions]

Yes. Because it’s when you hit the gas, the load on the engine increases and the vacuum drops. They open.

[@dalejrfan820002000]

@@MuscleCarSolutions Ok let me ask a dum guestion how will I know when the open?

[@MuscleCarSolutions]

It’s the wrong question. The right question is how will you know if they don’t open? The engine will fall flat on its face and not engine RPM/vehicle speed.

[@RandallSoong-pp7ih]

Awesome!!

[@barneywarwick1038]

i have a 93 dodge Dakota with the 318 it's fule injection now how can i get more horsepower out of fule injection if i switch over to carboraitor i was told go with the holly 600cfm 4bbl electric choke and the air gap intake and a return line fule pump regulator the transmission is ran by the computer can i keep the transmission

[@DesertRatFabrication]

Hey Bone, I am about to rebuild my Edelbrock 1406 fuel pressure is good, will be changing filters as well, the biggest problem I was having is a chugging when driving on a flat surface at about 10 miles an hour, not real bad but noticeable, with that being said as soon as I give it some gas snaps to life, so I thought I would just rebuild the carb, sense I just bought the truck a short while back (55 chevy big window), what do you think, thanks Mike

[@DesertRatFabrication]

Bone Head right on, thanks, should I try it the way it is after the rebuild first , probably ya

[@DesertRatFabrication]

6 psi

[@DesertRatFabrication]

6 psi

[@DesertRatFabrication]

But I only have the 8139 filter

[@DesertRatFabrication]

Is it ok to put both filters and regulator under the hood

[@bobbydelamar606]

If it's idling and burning your eyes, is that rich?

[@b.m.4066]

If it's gasoline and your eyes are burning from idling, it's running very rich. Methanol and alcohol are a little different but for a regular vehicle, yes

[@bobbydelamar606]

@@b.m.4066 Thank you. My plugs are black also. I'm installing a new carburetor.

[@MuscleCarSolutions]

@bobbydelamar606 not the carburetors fault. Adjust it!

[@bobbydelamar606]

@@MuscleCarSolutions I did several times. It doesn't want to idle. I have to keep the throttle open to keep it running.

[@MuscleCarSolutions]

@@bobbydelamar606 simple adjustments, a good cleaning or check your fuel pressure.

[@Michael-qy1jz]

Does it matter if you use the PVC port for Brake Vacuum???

[@MuscleCarSolutions]

Use the rear port for its intended purpose. It’s there for your power brake assist. Front is for PCV.

[@thebighair37]

Your have enjoyed and learned from other vids of yours. To the point of now having two questions... 1) Do all AFB and AVS carbs basically start with the same base/body, but only the jetting and metering rods are different? 2) If this is true, can I take a 1906 AVS2 and turn it into a 1903 by getting the 1903 Calibration Kit and just step the 1906 down?

[@MuscleCarSolutions]

You can change the CFM of those carburetors. That’s a fixed number that remains constant no matter what rods, jets, springs, squirters you change.

[@thebighair37]

I'm sorry, I'm not following. You are saying the CFM can change, so what is the fixed number then? Is there a typo or am I just missing something here? Thanks

[@MuscleCarSolutions]

@@thebighair37 typo. You CAN’T change the CFM. It’s fixed.

[@richardrohr5106]

Does an improperly tuned carb cause overheating?

[@MuscleCarSolutions]

If it’s really lean it can.

[@derwinrandle2682]

I having problems my 800 thunder carburetor to idle without pulling off transfer slots,help please.

[@MuscleCarSolutions]

What engine? What tuning steps have you done already? What is your fuel pressure regulator set at? What is your engine vacuum? What step up springs are you running?

[@JDorval319]

what discretion should I head to lean or rich? when your car hesitates and backfires when you go WOT., 383 stroker SBC, running a Edelbrock 1407,

[@MuscleCarSolutions]

@@JDorval319 head richer. Plus timing. Plus step up springs. Plus accelerator pump adjustment.

[@badthingsauto666]

just baught a brand new one the four barrels will not open unless i open them by hand...... I hate that sob and am ready to put my quadra jet back one any tips?

[@mrbeatty13able]

I have an edelbrock AVS2 650cfm. Which direction turning the mixture screws will do what? Ex: does turn the screws to the right lean out the mixture and left makes it rich or is the opposite true? Thank You

[@MuscleCarSolutions]

When you screw them in, you’re restricting fuel flow. Also this might be useful to you; kzbin.info/www/bejne/lXLKooeLf9drl68

[@mrbeatty13able]

@@MuscleCarSolutions Thank you

[@tonyvermeer7409]

I have a 1406. When adjusting the fuel regulator, do you set it for the MAX it will allow? I have mine set at 5.5 lbs. when it is at high idle. After I drive it then check it again, it drops to between 3-4.

[@MuscleCarSolutions]

I always start at 6 at idle and tune down from there as needed. I’d you’re dropping that much pressure, it’s likely one or more issues. Fuel lines too close to a heat source. You’re using a deadhead style regulator and they are famous for dropping some pressure. Put a clear filter before and after the regulator and see what the difference looks like. Once you get it sorted out, remove the filter after the regulator. We’re not a fan of one there. 😉

[@obcmissions]

My Edelbrock 1403 on a Ford 289 gave me about 200 miles on 10 gallons when I first installed it. After storing it over the winter it never was the same. It would idle roughly and there were various issues until it was discovered there was a vacuum leak. Now that is resolved and it idles fine as set up by my mechanic, I get barely 100 miles to a 10-gallon tank. Not sure where to start.

[@MuscleCarSolutions]

First things first. Storage on any carb means completely draining it of fuel. If you’re running pump gas, it’s got ethanol in it and with that comes all the crap that fuel attracts. Change your filters. Get a rebuild kit and give it a through cleaning and rebuild. Loss of economy can be a couple things and likely the clean and rebuild will solve some of it. Your next steps are adjusting the calibration spring under the piston that’s attached to the metering rods. You can try it with swapping them out till you find the sweet spot or a vacuum gauge to see what the manifold vacuum looks like while driving.

[@obcmissions]

@@MuscleCarSolutions Thank you, I will try that.

[@steelmill]

Good info,set that base line first then save the carb for last.Dont forget that pesky distributor cap and rotor.

[@suejackson8007]

I have watched this and some other of his videos. i have a 66 Mustang, slightly warmed over 289. My old Edelbrock1406 was just changed out to a 1906 AVS2. I replaced the fuel pump that was rated between 6-8 psi. New fuel hose and filter between the pump and carb. As recommended, I added a regulator. [A cheap one at first] No matter what adjustment I made, all I got was between 3-4 psi. So I upgraded to a more expensive regulator, and still only reads between 3-4 psi. His channel says Edelbrock's like a 5-6 psi reading. Help

[@MuscleCarSolutions]

@@suejackson8007 well it’s time to verify what pressure (flow) the pump is actually producing. Then determine if the pump is defective or you have something in the system blocking the flow.

[@tehyoyopro]

I found that when the ambient temperature was between 0-30 degrees (f) my 350 sbc ran great throughout the rev range. Now that it’s 60 degrees (f), at around 2000 rpm the engine backfires out the exhaust and sounds like gunshots. Thoughts? All ignition components were changed in the last 2k miles

[@tehyoyopro]

Bone Head I’ve got an hei distributor. I’m starting to suspect the vacuum advance diaphragm may be failing due to the engine falling on its face above 2500. Also takes more pump shots to start than it used to

[@raygee1138]

I'm running a pair of Edelbrock Thunder Series carbs (1803 & 1804) on a Pontiac engine. These are part of an Edelbrock top end dual quad kit consisting of the carbs, intake, cam, lifters & rocker arms. I've installed a pair of Edelbrock #8722 1/2" wood spacers under the carbs to alleviate heat soak. The problem I'm trying to overcome is a very rich idle, the tailpipes are black and if I'm in the garage with the car I could die! I've adjusted the float levels to stock and a little less with no difference, if I went too low the car would stall when I made a hard turn or fast stop. The carbs are set up with the as-supplied .086" primary and .077" secondary jets. I'm using a stock mechanical fuel pump and need to check the pressure output-at what point does fuel pressure overcome the needle/seat assembly? Thanks for your time and help.

[@raygee1138]

@@MuscleCarSolutions Copy that-and the good thing about this set-up is the carbs are only 500 cfm each, less than needed for the engine alone, and with 1000 cfm available at WOT there's more than enough for power runs. The car has no drivability issues, well, there's one but that can wait till later to diagnose. I've read that Edelbrock offers spring loaded needle/seat valves to avoid shock encountered by offroad use, maybe they'll help with a lower float level. Also, would you recommend leaving the original float drop setting or changing that as well? Thanks-

[@raygee1138]

@@MuscleCarSolutions I verified that the mechanical fuel pump is supplying a steady 5-6 psi to the carbs. Next step will be to adjust the float levels, do you have a recommendation for how much lower to go than the 7/16" specified by Edelbrock?

[@peteloomis8456]

Ray if your running a very hot cam with a lot of duration i have seen some Edelbrock carburetors run rich at the idle circuit because the vacuum is too low from the cam shaft duration so what do guys do is drill a small hole in each primary throttle plate to allow more air to come through at idle circuit idle ! Had a guy at the shop i worked with that had this problem on a 70 440 Challenger that was doing the very same thing because he had this radical high duration cam shaft and with small incremental changes on the hole fixed drilled in those front throttle plates he was able to get it running much better to a point it not only pulled harder out of the hole it also wouldn't burn your eyes at idle in the shop anymore . He tried lowering the floats as well as leaning up the primary jets but that still didn't do much until the holes were drilled !

[@hdld7371]

what spring do you use if you pull 20 inches of manifold vacuum?

[@MuscleCarSolutions]

Start with the silver spring.

[@moncefdif6372]

great video. i have an issue with my jet boat its 21 ft aluminum with 1410 Edelbrcok marine and 350 chevy. boat starts and idles , and cruises fine but when it gets to 3600 rpm it wont go any further. if i push the throttle it it starts spiting and stumbles and have no further power . thx for the tips

[@moncefdif6372]

@@MuscleCarSolutions thanks for the comment. to be honest dont know much myself about what was done to the boat .just purchased 3 months ago from a heavy duty mechanic shop owner. he told me the boat is fine it just need new jets and carb adjustment. the boat has electrical fuel pump so i just added a holey deadhead regulator thinking it my be over-fueling but i have not taking to the water to test yet. i purchased the carb jet kit but I have not open it or install it yet because I though I will try one thing at the time to see if the issue goes away before i pour more money on this.

[@moncefdif6372]

@@MuscleCarSolutions i just run into this google comment that says "If the carburetor is "too big" then the engine will not be able to keep enough air flow through the barrels for fuel delivery to occur. Which would explain why the engine would work at highway speeds but struggles at low rpms. Jun 8, 2010" Howver, mine is the opposite , it runs fine in low speeds but struggles at higher speed.

[@moncefdif6372]

@@MuscleCarSolutions will do thx again.

[@buddyroper1174]

Why don't my secondary open on carburator it's on 350 with big cam any suggestions

[@darrellkidd3676]

GOT A DEAD SPOT WHEN HITTING IT FROM THE GET GO. ITS A 600 CFM ON A 383 WITH A ROLLER CAM.I HAVE JETTED IT UP STILL HAS A DEAD SPOT ON INITIAL HIT.

[@MuscleCarSolutions]

Adjust the accelerator pump? Change the squirter size?

[@garystump1776]

I very much enjoyed your information, just got an old plymouth with 318 with edelbrock 1405 ( and year built carb 0462 how do I read what year this is

[@ranbow2316]

Thanks man for helping me on the Facebook group. You the man

[@MuscleCarSolutions]

Awesome! You’re very welcome!

[@andrewbutton5580]

On a cammed 350.chevy with a tunnel.ram.what should the primary jets be ? Should the springs be lighter if the cam is large ?