Top 4 Carburetor Tuning Mistakes

[@vintagespeedandperformance6615]

Thanks for another quality video. Another best practice when tuning a carb, change one thing at a time, drive the car, determine how the engine reacts, make another change and repeat as required to achieve desired results. I see a lot of “I changed the main jets, power valve and secondary spring then went for a drive, now it’s doing this…”. Whoa buddy, slow your roll, let’s take this back to baseline and try again. Changing more than one thing at a time will result in chasing your tail, especially for a noob.

[@teymac8127]

I want to thank you for helping me tune my Edelbrock Performer on my BBC. I watched several of your videos and followed the instructions. Used the tuning guide with small changes and 14 degrees of initial timing. Runs great now and I couldn’t have done it without you!

[@MuscleCarSolutions]

@@teymac8127 nice! Good work! They’re so much more fun to drive when they’re working well. Glad the videos were helpful!

[@Ratridez]

A lot of poorly tuned carburetors is due to people not understanding the symptoms to begin with , torque converter stalls speeds make a difference to . Awesome video straight to the point and common sense 👍👍

[@johnweaver8470]

GMC is looking good, can't wait for the Chevelle build keep the videos coming

[@MuscleCarSolutions]

@@johnweaver8470 it’s my priority this winter. I’ve got a lot to get done! Thanks man!

[@meek01__53]

Thank you for sharing your knowledge, just put a fairly built 351with a AVS 2 carburetor on it (425-440 hp) in my 67 mustang convertible and want her to run properly. Will be on the streets shortly and want her to stand proud.

[@AndrewReiwitch-sw9lf]

As usual, awesome content!! Thank you over and over!!!

[@MuscleCarSolutions]

@@AndrewReiwitch-sw9lf thank you!

[@VinoRatRodbuilds]

Ditto! Very helpful info. 👍

[@MuscleCarSolutions]

@@VinoRatRodbuilds thanks Vino!

[@tomnekuda3818]

Again, great video with lots of info. I can vouch for the Edelbrock tuning sheets for setting things up correctly.

[@MuscleCarSolutions]

@@tomnekuda3818 it’s one of the things that make the Edelbrock an incredible street carburetor.

[@DesertRatFabrication]

Really good video Brian, so glad you touched on the timing, when I finally got my distributor dialed in I barely had to do anything to the carburetor, sure do like the digital E-Cruve distributor, oh and I did change the step-up springs in the 1406, catch you soon buddy 😀😀

[@MuscleCarSolutions]

@@DesertRatFabrication your video was very good at pointing out the intricacies of that ignition system. Timing cures a lot of sins! Thank you sir!

[@DesertRatFabrication]

@@MuscleCarSolutionshey Brian, I did want to ask you , do the metering rods match the jets in the kit, I couldn’t really see the numbers very good, I will bring a magnifying glass with me this weekend, like I told you before I only changed the step-up springs and it took the little hesitation I was having off idle, but that was also before I put the new distributor in , but even now the vacuum holds the metering rods down until I give it a little throttle then they pop right up, before I changed them they were lifting when idling, all good now though 😀😀

[@MuscleCarSolutions]

@@DesertRatFabrication the rods and jets are matched sets on the tuning chart. They are calculated to give the precise amount of fuel for the conditions on the chart. So if you’re on the base calibration (1), and you want to go leaner in the cruise mode but make no changes on the power mode, just follow the chart down till you’re close to the first stage of lean (4%) and try that. I did a full video on how to read the chart if you need a little refresher. 97% of the time, I follow that chart exclusively. Takes all the guess work out of it! Such a great tool to have.

[@MuscleCarSolutions]

@@DesertRatFabrication you’re spot on with the step up spring as your first change. Makes the whole tuning process go much quicker and you’ll get better results. You’re a pro at this now! 👍

[@DesertRatFabrication]

@@MuscleCarSolutions thank you I will check it out again 👍

[@shootermcgavin2819]

Another thing i notice is people "tuning" their carburetor with the engine cold. Warm it up first.

[@MuscleCarSolutions]

@@shootermcgavin2819 absolutely!

[@Cradletothegrave67]

There is a large part of the timing issue that was missed. The understanding of total timing and the amount of centrifugal advance in the distributor is imperative to maximum power output. Reducing centrifugal advance in the distributor allows maximum initial timing on the crank shaft, without the total timing exceeding an acceptable limits. The extra initial timing increases vacuum signal, booster signal and response and low speed torque as well.

[@MVPisME383]

I swapped to holley dp and used fuel log with a gauge and found my sbc mechanical pump was pumping 12-15psi, put a regulator on and had to reset my fuel bowl level and it was idiling 15:1 AFR and i ran a Edelbrock 650 avs2 with that pump and no regulator since 2018 i know why my oil smells like gas now

[@erica8664]

Very informative as always thank you.

[@MuscleCarSolutions]

@@erica8664 thank you!

[@DesertRatFabrication]

Hey Brian, I see you made it to Sema again , would love to go sometime, thanks for sharing, hope you’re doing good 😀😀

[@bluejayfabrications2216]

Twin fuel fiters is NOT overkill i run three in my cars clean fuel cant be overstated

[@MuscleCarSolutions]

@@bluejayfabrications2216 I agree.

[@edcucchiarella7994]

Thank you again, great video!

[@MuscleCarSolutions]

@@edcucchiarella7994 thank you!

[@ДмитрийФакухин]

Thank for your video! It's really little red Edelbrock 38GPH fuel pump are too small for most applications? I use it with near-stock 351w, F4TE, ported heads, 8124 Weiand intake, HEI distributor and AVS2 650cfm carburetor. I use dual feed, big EFI fuel filter, custom made pressure regulator and high-sensitive industrial-grade pressure sensor. My fuel pressure set is 0.379 bar/5.5 psi. Runs pretty good, but now I hesitate... Maybe that flow is too little? Sorry for my English, I'm not native speaker.

[@MuscleCarSolutions]

@@ДмитрийФакухин that pump will be ok for idle and some light cruising but if you’re asking for it to keep up to higher rpm and more aggressive driving, I’m afraid it’s not capable of that. No need to apologize for your English. You communicate very well.

[@ДмитрийФакухин]

@@MuscleCarSolutions Thank you for answer! I'll think for something bigger, maybe Holley-style pump...

[@ourkid2000]

Great video! I find the advice on timing a bit confusing. My '66 Olds specs calls for the initial timing to be set at 7.5 deg BTDC (i'm at sea level). So you're saying, with today's pump gas, this isn't quite what the engine will want? So bump it up a bit at a time? How far do you go.......just keep bumping it up until you start to hear pinging on acceleration? That would actually make a great video......finding the correct timing.

[@MuscleCarSolutions]

@@ourkid2000 eventually I’ll do that video. Setting timing seems to be a topic that no one wants to tackle. If it’s a V8, you can generally start at 10 degrees BTDC. The engine will tell you if it does or doesn’t like it. I did an Olds 350 early this year and I think we ended up at 12 for initial timing. Todays fuel sucks. That 7.5 was back when there was lead in the fuel and it had great properties for combustion and energy capabilities. Those days are long gone. Have to adapt to those changes.

[@ourkid2000]

@@MuscleCarSolutions great reply! Thanks so much. I have mine bumped up to 9 degrees but I'm too chicken to go any further and I have no idea if it even needs it. It's a fairly high compression big block (425 Toro).

[@MuscleCarSolutions]

@@ourkid2000 starting is also part of that understanding what the engine wants. When it drags the starter and is harder to start, you might have a bit too much initial timing. Lots of things to monitor but it will let you know when you’ve gone too far.

[@fasteddy]

​@@MuscleCarSolutionsok 10 degrees mechanical, how much is vacuum adding to the 10 degrees? Thanks

[@ryanholder6461]

I love it!

[@joseduranjr4963]

Any advice on running a stock replacement 2 bbl carburetor on my 1979 Lincoln Mark V with the 6.6 400 engine

[@MuscleCarSolutions]

@@joseduranjr4963 depends on the CFM of that carb and the operating rpm of that engine.

[@RandallSoong-pp7ih]

Awesome thank you!!

[@Jack_Move]

What are your thoughts on AVS 2 series? Was thinking of swapping out a Holley 650 double pump spreadbore ( Have adapter for Squarebore intake ) for that in 500cfm. The Holley is jetting down to 59 I believe on the primaries & have power valve changed to 3.5 so it opened earlier. It's on a med built chevy 4.3L v6, its punched out 60 over on the cylinders & non stock cam as well. Full MSD Offroad CD Ignition also. Max vac pull at idle is typically around 15. Trying to have a balance of fuel economy but have power if needed. Is a street\ off road vehicle on 35" tires, standard shift non auto.

[@MuscleCarSolutions]

@@Jack_Move you’re running a 650 double pumper on a 4.3? Yowza! Yes, any 500 would be better on that poor little 4.3L. We’ve covered the AVS2 series carbs since they came out. Great street and off road carb.

[@Jack_Move]

@@MuscleCarSolutions It doesnt flood out or anything. After switching the fuel system to the Holley from TBI, The general power curve jumped dramatically. Low rpm power went through the roof & finally also had enough to feed it in higher rpm range 4K-6.5K . Cylinder compression is at 195-205psi which is way higher then the stock 140-160 ish they were.

[@Ratridez]

A big pet peeve of mine is people running the $1.99 see through plastic filter and cheesy hose clamps right on top of their high end build 🤣🤣

[@MuscleCarSolutions]

@@Ratridez it served its purpose.

[@BrianD146]

Add two-barrel mercruiser carburetor on 3 l 4-cylinder engine. Old carburetor what's having trouble idling Got a new carburetor and it's running way too rich. Wondering if the primary jets are too big They gave me a set of two different size Jets

[@MuscleCarSolutions]

@@BrianD146 the main meting circuit is generally not part of the idle circuit. I’d do a little homework on that before making that assumption. Fuel pressure is just as critical on a two barrel. What is your fuel pressure at the carburetor? Don’t know? Time for a regulator and a gauge so you can control it.

[@ryanholder6461]

Real Deal,

[@flinch622]

Thumbnail sketch: the difference between Denver and Houston demands a jet change - 3 or 4 sizes, depending on the carb.

[@MuscleCarSolutions]

@@flinch622 link to the elevation video we did is in the description and much more is needed than 4 jet sizes.

[@Thumper68]

I moved from 2500-3000ft in Washington to near college station and I didn’t have any issues beyond little tuning no jet changes though

[@cuzz63]

@@Thumper68 500 ft isnt that much...

[@Thumper68]

@@cuzz63 no where I lived was 2500-3000 now I’m near college station tx

[@cuzz63]

@@Thumper68 ok, I guess I read it wrong,

[@toast_fairy1419]

i'd say the big problem is not the carb tuning but that hei distributer XD

[@MuscleCarSolutions]

@@toast_fairy1419 no problems at all for that application.

[@robertchavez2864]

I have a 1400 Edelbrock Performer how do you tune a smog carburetor

[@MuscleCarSolutions]

@@robertchavez2864 you don’t. Or technically you can’t of you wish to keep its EO status. That carburetor is limited on how it will perform. It’s a choked down 1406, which is very different that the manual choke 600.

[@robertchavez2864]

@MuscleCarSolutions I have a 500 CFM Edelbrock sitting on the sidelines. I was told I could transfer everything from my 1400 to the 500 cfm

[@MuscleCarSolutions]

@@robertchavez2864 will it physically fit? Yes. The channel sizes in the main body are different. You’d have to knock the plugs out and drill them open and seal back up again. The real question is why would you want to take the choked down smog carburetor boosters and put them into a 500 body?

[@cyberterro]

プラグの焼け具合で燃料の濃さを判断してる。 最近のイリジウムプラグだと判断が難しい。

[@MuscleCarSolutions]

That depends on how you’re reading the plug. Most don’t read them at the correct time or method.

[@christopherpoucher483]

I'm thinking my regulator Isn't enough max setting only 4 psi rated, engine has low power...

[@MuscleCarSolutions]

@@christopherpoucher483 remember the regulator restricts FLOW (I did a video on this topic). PSI is what is controlled to ensure the carburetor runs properly. 4psi is quite low, depending on the application. For some, 4 is extremely high! What are you working on?

[@christopherpoucher483]

@MuscleCarSolutions sbc 400 vortec heads mild cam had a 1405 I took off my 350 that felt under powered put on this engine and it's the same. Swapped to my 1407 it's better but still not right has me thinking 4 psi 3/8 lines hi flo mechanical pump timing is 10/32

[@user-dc7im7id5q]

@@christopherpoucher483 I just put on a 1406. max is 6.5 but recommended was 4.5-5.5 at idle. similar build to you just a 350

[@christopherpoucher483]

@user-dc7im7id5q my pump is rated at 6psi but my regulator is rated at 1-4 psi, I'm ordering another that's rated 4.5-9 psi

[@christopherpoucher483]

@user-dc7im7id5q what carb are you using?

[@Texasmule]

👍💯

[@MuscleCarSolutions]

@@Texasmule 😉👍

[@patrickwendling6759]

Thank you for your knowledge and videos TRUMP USA 🇺🇸 MAGA