How to Tune an Engine - Initial Settings, Ignition, & Carburetor Theory of Operation 

As a younger guy just starting to get into the world of fixing an older carbureted vehicle for the first time. This is hands down one of the most valuable videos I’ve stumbled upon thus far. Thank you.

There’s more to teaching than simply having the knowledge. YOU have it all young man. Thank you very much, the teaching will be put to good use on my 1952 studebaker commander land cruiser v8 rebuild. Thank you.

I'm pushing 40, been screwing with carbs for the past almost 30 years. I can get them to work, I kind of know what I'm looking for. This is the best explanation I have ever heard, and it makes me realize how much banging my way through tuning a carb was mostly dumb luck. Thank you

Bro your amazing with these videos. Keep up the hard work and here’s something that might make you more happy. I’m a younger person at 13, and I really want to learn about cars so this video taught me a lot. Thank you!!

You could not have released this at a better time. I just finished a 2 barrel to 4 barrel conversion and as this my first project car and it runs like crap, I am about to start this process. Beautiful to see how this is done, step by step, from start to finish. Thank you!

I really feel like you could be a great automotive instructor. You don’t talk over peoples head that aren’t experienced. You take your time to explain and are thorough. You’ve got so much knowledge and patience. Thank you for always putting out GREAT content.

I said it before about the camper video, now I find myself saying it again after watching this video. Thank you. This is still the best explanation of carburetor operation and tuning I have ever seen. I only wish I had gotten this level of teaching when I was in auto school years ago. This explains so many things that didn’t know I was doing improperly for a long time. Thank you for helping my dumb ass get a little smarter.

Great guide! I'm a very digital person and always had a harder time understanding carburetion versus computer/EFI control. But I'm planning to build a retro street rod in the next couple years and fuel injection just doesn't feel right for what I have in mind. So this is a great start-to-finish for essential understanding and tuning that I will probably be coming back to later. Thanks!

VERY WELL DONE! It's been years since I was sitting in my high school auto mechanics class learning about carburators and you brought it all back to me in this video. Actually, I think you did a better job explaining everything than my teacher. I really enjoyed the refresher course! Thank you!!

I remember the motor home table talk. I got a LOT more from this edition. Thanks so much for the lesson.

I like the way you approached explaining this and appreciate you taking the time to do so. I personally have two things I do first before getting to the beginning of your list. 1. verify the harmonic damper is in good shape. A bad one can have the ring slip and your timing marks are worthless. If we are trying to deal with an older car with a carb we are talking a vehicle that is at least 35 years old. The ring is held with rubber. Rubber can fail, it cost me 18 years of child support. 2. With the distributor cap off, bar the engine opposite of rotation until the rotor moves. Then bar the other direction to see how far you can go until the rotor moves again. If the thing already runs like ass, it might have nothing to do with the carb and just have a stretched timing chain. You need to know your valve timing is true and correct before doing anything or there isn't going to be a point in fiddling with it, no matter what you do it will run like ass. When it can't be driven, you can't get to work to pay the child support from the time you trusted a piece of rubber.

I've been hoping you would make a video dedicated to carbs. Now to watch it several times and learn everything to know about carbs, even though I'll probably never work on one

You sir are a blessing, this is the video that finally helped me get my old mini truck running again. Up until you released this all the resources I found only helped me to make it stop running or run poorly. Now she's purring like a kitten!

Great work! Now I've got to go and get a car to work on. They say if you can't explain it simply you don't know the subject well enough. Your explanation is perfect.

Hey dudes, waiting on you to create your new channel, Barn Yard Digs. I need my agriculture based revival content man

I’m new to carbs and have been lost for months while watching numerous other videos on RU-vid including ones from professionals at places like Holley. This is hands down the best video on the subject out there. I feel like I actually know what I’m looking at when I try to get my car tuned. Thank you for this!

I've watched a lot of carb tuning videos, but this one truly brings it all together at a level that is appropriate for most folks that make up the street tuning masses. Well done and thank you for your time here!

Well done Kevin, really. I am 63 and have been building Holley Carbs since I was 15, and I think this is a great overview view of a Holley, and basic tuning procedures. I have an old SA Designs book on Holleys that has notes and jet numbers, etc on the inner rear cover and in the margins of pages. I was 16 when I wrote most of that stuff. That book is also a great resource if you can find one. It might be helpful to talk at some point about the things to never do with a Holley, like over-tightening the float bowls, or the base plate bolts, etc. I run into so many carbs idiots have had there hands on with warped metering plate surfaces because some clown couldn't stop and change a gasket and tried to tighten the leaking gasket away. I was happy to hear you address the mixture screws with the caution on over tightening...another place the ham- fisted idiots leave traces of their "work".

Great video , very well covered and nice and clear . Dealing with carbs. is becoming rare so to find someone that is good at it is getting harder and harder . It is great to see younger people taking a interest in this topic and Knowing what their taking about . Thanks for taking the time .

Thanks for sharing. I saved this so I can come back to it in the future when I forget about carburetors again.

Sheesh I had to become 67 till I *really* grasped the function of a carb - thanks to your very instructional video! Many thanks for this - you are a natural teacher!

Super stoked for this one. I haven’t messed with a car/truck carb in years.

Honestly, you could be a shop teacher. Very easy to understand what you are saying. And obviously you are not just blowing smoke because the trucks you work on always seem to run good. Thats proof enough for me. Great video!

My son, dad, and I flew back to WV and drove my grandpa's last truck, a 79 Chevy K10, 2200 miles back home on a trip of a lifetime. It had been parked for 3 years and had only been "farm maintained" before that. We wrenched 4 days straight to get it ready to make the drive. I almost put a fuel injection kit on it because I was that scared of carbs and didn't know if I could get it tuned good enought to drive accross country. We ended up putting a new Accel distributer and Edlbrock carb on it and I was able to comfortrably "tune" it because I had watched and learned from you and your crew. That old truck drove the whole way withough a single glitch. Tuned it with a vacume gauge, set the advance on the distributer, read the plugs half way. What an epic trip with my family! All that to say thanks and keep up the good work!

Absolutely the most comprehensive video I've ever seen. Of the other videos watching you speak on timing I was still shaky on the "total timing" but you did an amazing job here and my understanding of these systems has definitely increased by a lot! The time and care you put into these videos definitely shows man thank you

Tuning mixture screws using a vacuum gauge is some of the most satisfying wrenching experience I've had. Well, screwdrivering I guess. But anyway, setting timing, checking to see if the mechanical advance works, getting the idle smooth, using the timing light, all this, it's a skillful art and if you know you know. YOU definitely know and sharing that knowledge makes you a stand up guy. Great video, even if you feel it's all over the place, well, this is how it is with these cars, you get started on a process and then two more things need fixed before you can get back to what you were doing. In this case, the advance springs jamming up and running out of fuel were the two that got you!

Great job explaining and demonstrating how to perform the timing and carburetor adjusting. I have a lot better understanding now of how the circuits within the carb are to be adjusted. Your ladder diagram made total sense! Thank you!!

Solid instruction. Many thanks for detailing the tune in a well spoken, natural, and even-toned way. A compilation of focused teaching per individual engine component (for a common V8 build say) would I expect be extremely popular; maybe even lock-in your channel for 1M subs. Appreciate the consistently excellent content.

Kevin, I'm60 years old and I have to say you are the best teacher I've ever seen. Great job dude! Watch everything you and Look do👍

Thanks for making this video my dad and I were working on restoring my 1967 c 10 and unfortunately he passed away before he could teach me how to tune it properly. This seriously is the best video I have seen explaining the process and I have a way better idea on how to do it. Thank you guys

Amazing, very much what I needed to see for working on my cars! You are the only person to actually describe how a carburetor works in a way I could understand without relying on "oh yeah just do XYZ and it'll run better", those people never explain why (probably because they don't know why). Looking forward to more "Tech Tuesdays"!

Instead of using paint, you can also use white out. Been using it for years with it never chipping, cracking, or peeling. Great video.

WOW! WHO KNEW ALL THIS FUNDAMENTAL APPLIED PHYSICS WAS INVOLVED IN THE MECHANICS OF SETTING THE TIMING AND CARB, I HAVE TO KEEP THIS AND GO OVER IT AGAIN AND AGAIN SO I CAN TEACH THIS TO MY BIKER LADY FRIENDS. THANK YOU.

Very proud Kevin this video shows how much you care about your community that you've created on RU-vid and how far you've came. This is honestly amazing and I'm so happy to see how far you've came in your RU-vid career. Good Job

Yes bro I've needed to learn this and I still don't know how to tune brakes dispute I've watched half your channel in a day!

I really like this guy. Plain talk, common sense approach. He obviously knows what he is talking about. Very helpful video, thank you.

Excellent job. I really enjoy these in-depth educational videos. You teach it well. There's a lot of info here that seems to be lost to many people wrenching on old cars and such.

Beautiful. Brings a tear to my eye.

That was probably the only real lesson on carbs and timing ive ever been given, and although i have to re-watch it 50 times to make it stick in my brain, it all made sense and will be critical in making my project run one day. Thank you so much for doing that.

Most the carbs I work with are Japanese CV carbs and Weber 32/36 series. Any chance on covering something like those? I only ask because you have a way of explaining things that even my dumb self can understand! Keep up the amazing work guys!!

That last ten minutes are gold! I have never been able to fully wrap my head around the function of a carburetor, but I think I am finally able to start understanding it with your ladder analogy. At the very least, that explanation gives a very clear order to the tuning process.

Mr MoJo gets around and helps you like a man half his age....and he does so with an immense amount of knowledge. He's a good dude, glad you have him around. 😁

I have a 1966 Mercury Comet with a stock 202 straight 6 and with the stock carb on it, I'm 17 and this is only my second time doing anything big to a car in terms of tuning and this has helped me a TON to actually understand what I'm doing so thank you very much for this video and making a refresher course over it. I will definitely be coming back to watch this again.

This has been the most comprehensive illustration of a carburetor and its performance from start to the end, you have made me feel like an expert. I can go out to my car with confidence thank you very much . Elwood

Man I love your videos and I hope you can do more instructive content like this.

This was super cool. I've only ever messed with small engine carbs, but never really KNEW how a automotive carb functioned. Loved this! I "helped" my little brother figure out his ol ram charger, and I bumblefuked myself into a solution and got it running.....somehow.....but it never actually had POWER. It could never get itself out of a hole it dug. If only I knew what I knew now, he most likely wouldn't have sold it.

This is the video I have been looking for, without a doubt the most comprehensive one out there. Easy to understand and I learned a ton. Installed a wideband and can't wait to get tuning.

*"The best time to plant a tree was 20 years ago and the next best time is now"* I consider this to be best motivational quote I've heard in a very long time. But motivational quotes are useless if you don't practice what you preach*

I know I'm a year late but thank you so much for this. All these videos were so confusing when it mentioned best possible vacuum. This cleared a lot up for me and helped me get my car running right again. So again thank you so much for this tutorial.

I'm really happy that you made this. This is the most informative carburator video I've seen yet! It's starting to make much more sense now.

Nice job.good to see old school tuning again.

Awesome video! I’m amazed how few comprehensive carb tuning videos exist. Because this is true, people tend to tinker with a specific setting because they saw a video on power valves, jetting, or accel pumps without understanding how all these systems interact with and effect each other. Everyone who runs a Holley style carb should watch and bookmark this video.

thankyou for this video its really gonna help me with the problems I'm having getting my first car road worthy

Thank you for showing how to do this. My youngest son is getting married 5/18/24 and would love to get his '78 Nova running and actually drive it for the wedding & reception. We have it running for the first time in 10 years and it is a complete block rebuild 355 with a mild cam and rebuilt heads. It runs if you hold the throttle open slightly, but then dies. I want this so bad for him but not sure if it actually will as the guys that were to help tune it are booked-up. This project started as a high school kid mowing yards to buy his first car. He bought it but never actually was able to drive it. Hopefully he will be and to in less than a month. Love the videos & thanks again...

thank you, that was one of the best videos that i've watched in a long time

Id like to say I learned so much from your video, I've been doing it all wrong alot of years, your video explains so much and id like to say thank you for your knowledge and taking time out to share it, I truly appreciate it

Thanks for the video on tuning and carbs. adjusting. This is the best video I've seen, and it's very thorough. Thanks for your help!

Fascinating! I've only ever touched a small engine carb which I do basically by ear (plus tiny Tach if I'm feeling nerdy or anxious), none of this vacuum gauge or timing business 😁 On the other hand, my old car is just good old VPW OBD2 and I don't get a KR live data unlike the newer car folks on RU-vid...

I’ve been watching your channel for a while now, I really only watch you and Project Farm. I needed to better understand how my timing light works and you answered my question perfectly with how the knob on my timing light works. Thank you from Texas. 👍👍

Huge light bulb moment for me thank you!!! That was the most complete and easy to understand explanation I have seen yet!!

Just got a whole new level of respect and appreciation for older gear heads( not that I didn't before) but just rebuilt a 750 eddie and after this feel a bit better about tuning the holley were switching

Very well done! I’m one of those people you have to draw a picture. I understand completely now. Thank you!

This is an excellent video. Very complete and understandable. I was able to tune my carburetor after struggling for the last month. Great job, really enjoy your videos. I’m an old guy but you taught me something , thanks

Thank you for blessing us with these great videos

As others have already stated... Very well done!! Ive been trying to tune the carb on my 408w and have it close, but Im convinced (and my AFR gauge confirms) that there's still some room for improvement. Thanks to this video, I think I now understand where I need to focus my attention. Well done!

Great video and excellent explaining... Was just working on my truck this morning and ran into a few little carb issues.. watched this video the refresher course was wonderful thanks JYD keep up the great videos!!

I used your idle set screw technique today (go until there’s vacuum then back off until there’s none) worked like a charm!

Dear Kevin, I have 45 years in the trade, spent 5 years apprenticed and hold a master craftsman cert, I know you was doing the best you could with the tools available, but you managed to teach me something new, well done spot on, on point pal. hi Mook 👌

I had never heard about setting the transfer slot with a vacuum gauge. Not even Edelbrock mentions that in their "Owners Manual" ! That method is brilliant! Thanks a bunch!!!! Your reasoning is spot on.

Excellent information, sir! I'm going to be building a carbureted 289 in the near future. Glad to see there are still people out there that know this stuff. I really enjoyed your method and delivery and sure learned a lot from your video, thx!

Great video !! I've been fighting timing for two years now and can finally time and tune my carb and motor correctly. Loved the transferr slot finding without removing the carb ❤ Thanks for the clear and detailed video man !

I’ve said it before and I’ll say it again…you belong in a classroom. You explain it in a way that makes it sooooo crystal clear that the only way you can’t understand is if you’re not paying attention! Kudos!

Too many carb videos neglect the importance of timing and you did a great job demonstrating the relationship between the two

I bought a 78 Super cab with a 401 here in aAustralia a few years ago, without your channel it would not still be on the road! thanks you so much

Dude, seriously, great content. Thank you so much. I love the channel, the people, everything. I have heard about other RU-vidrs loving Ford and I couldn't figure out why, now I think it's because they're so much easier to work on and understand. Maybe not. I don't know. Great content!

Nice. You're a good teacher, man. You explained all of this well enough for me to follow, and answered some questions that I couldn't find in other people's videos. Cheers!

Perfect timing on this video! I'm working on a '72 Ford F100 with the 360 FE that I've rebuilt. I don't have a ton of experience with carbs, so this video will help a ton with getting it running just right!

The best tuning and carburation video I've ever seen. Thanks a lot mate.

Genius! Thank you so much for this informational and instructional comprehensive video on carburetor tuning along with engine timing! I have never found an instructional video which is so easy to understand and comprehensive! You just helped me fix my ride sir! I’ve got a 1963 Chevy C 10 show vehicle, with 383 Stroker. I have been struggling I know now exactly how to fine-tune thanks to your video! Thank you so much for this!

I'm learning how to do this for the first time and so far this is the very best video on the topic! Thank you.

Excellent video Kevin! So many people have added an AFR, but I'd yet to see a good breakdown of what you should be looking for in the different driving conditions. Well done!

Your videos are the simply the best I couldn’t find anyone else that explained it like this now I know why my truck wouldn’t pull fuel going to make the changes necessary tomorrow and see if it works. Keep doing what your doing making great content I’m new to owning older vehicles so I never had anyone explain everything I have had to learn everything on my own or simply guessing my way through it

Thanks this helped alot I also loved your other videos

Awesome always guys 👏 😎

For a distributor with points ignition before you set your initial timing you need to make sure your dwell is set correctly because, changes in dwell will affect your timing, also when setting initial timing make sure your idle speed is low enough to where your centrifical advance hasn't partially engaged. a Holley double pumper is designed and sold primarily for racing and are okay on the street as long as you aren't the one paying for your gasoline.

One great educational video. Well done :)

Excellent tutorial. been running carbs for so much longer than you have been alive, but you're the first one to thoroughly explain it. WELL DONE. Love the ladder analogy. A true educator can take a complex concept and explain it so the morons (like me) can understand it, you should have a Masters Degree in education.

Absolutely, amazing video. Whoever taught you how to work on carburetors did an extremely good job.

This is exactly what I needed to know for my 76 F250. I rebuilt the 390 for high compression and threw an RV cam in it, so stock tuning was out of the question. Today I'll apply these and see how well I can really get it to run!

What an awesome video 🤘

Fantastic video Kevin! Thanks for taking the time to make a very detailed video.

Was taught "vacuum" theory by my grandpa. Used a livestock syringe. Had me pull air into the syringe as hard as fast as I could, and then trimmed the end off of the syringe. Was a perfect teaching mechanism.

Havent even seen half the video yet, but I can say for sure that this is the best video I have seen on these topics. Well explained in simple terms and I like how you took the time and effort to show and explain the problem solving with the distributor weights when that showed up. Thank you very much for the video - Great learning for me.

Excellent explanation. I'll be utilizing all the great tuning tips when I drop in my new Corvette distributor this weekend. This was the video I needed, when I needed it! Was on the fence about getting the dial timing light for the job, and the addition vacuum tests to dial things in... perfect. Thank you!

You do a great job teaching. You make it simple and to the point.

This was FAN-FREAKING-TASTIC! Not even Holley's own videos can compare to this!

I’m so glad you did this! I’ve been watching a ton of your videos over the last year and it’s really making me want to do what you do! Thank you for acting like the gearhead family I never had lol

I've got an old bullnose f100 that's been giving me trouble for a couple years now, and I'm thinkin this is gonna give me the kick and the knowledge to finally get it sorted. Fantastic video!

Excellent. I’ve had to figure this out on my own now for the past 2 years. Much appreciated.

I absolutely love this, because while you can pick up things from regular JYD vids, I love these instructional videos that really focus on teaching