Tuning the SU carburettor, Part 2 Practical

[@paulcartwright5438]

Thank you so much for this fantastic content! You are a born educator. I have just purchased my first classic car - a beautiful 1967 MGB GT - and I'm working hard to learn how to service and maintain it. Your videos are a goldmine of well-structured and well-communicated information and your willingness to share your expertise is helping me immensely on my journey.

[@andrewcoull492]

Absolutely fantastic video clip , I’m restoring an old Riley 1.5 with twin HS4 I just can’t get them set properly , you’ve helped me understand SU’s a bit more , Thankyou

[@jamesnorman7552]

Great series of video’s, thank you. Just in case you are interested, I’m running a 1971 Harley-Davidson with a Hif 44, it has to have no oil or even the damper in the dash pot but it does have an 8 oz spring.

[@rolandeid448]

Classic mini owner myself and wanted to adjust the carb after fitting new air filter Amazing content and very informative. Thank you so much

[@D3Sshooter]

Thanks and good luck with the mini

[@mmurphy1487]

Brilliant video series on the su carb, your explanations are clear and concise. The quality of the video is fantastic and very informative. I have recently installed an AFR gauge on my mini with your help. Well done! Kind Regards from Madrid, Spain Matt

[@bleizbreizh6264]

What an excellent series of videos, the best I have seen on the SU carb. and tuning of this type of classic engine. Thank you for making them. I can see that the good old colourtune might have advantages with a twin carb set up too. I have been looking round for ideas to reduce emissions on my old MG as I have been told that if I import it to where I now live that its yearly road tax will be directly related to the tested emissions output of the car as it will be regarded as a brand new car despite it being 70 years old! That air/fuel ratio gauge has really given me something to think about

[@severinoantonucci5580]

Smashing video, best I've ever seen on the topic. Very plain and clear explanation. Oh and comprehensible speech. Thank you very much.

[@D3Sshooter]

You're very welcome

[@SteveCrook]

Excellent comprehensive explanation of SU Tuning options. Thank you.

[@D3Sshooter]

Glad you enjoyed it!

[@shakeyjakecw]

Thank you so much for your advice on the hif44, been pulling my hair out trying to get my mini to idle smooth, and with your advice on getting the jet flush first then turning mixture screw two turns clockwise, it worked fantastically, thank you so much 👍👍top bloke 👍

[@D3Sshooter]

Thanks for the comments

[@michaelmenard8913]

Without a doubt, the most well explained video I have ever watched. Very concise and interesting.

[@D3Sshooter]

Thanks for the comments

[@michaelmenard8913]

@@D3Sshooter how do i get stuck needle holder out of slide?

[@jeremysleeman9127]

Thank you so much for your videos. Very easy to understand. Always informative. Keep them coming. Mini owner UK

[@brianmac8260]

Having some SU woes rebuilding a Rover 2200TC. Nice concise information here. Thank you.

[@D3Sshooter]

Glad it was helpful!

[@PaulyDownUnder]

Fantastic SU series from AEM meter install to this Part 2 tuning. Would have been good to see the plotting of the AFR graph again, comparing the initial data obtained with idle, 1st , 2nd , 3rd, 4th, cruise and WOT to what you have now. Thanks for sharing your knowledge and putting together the videos, i also really enjoy your teaching technique.

[@D3Sshooter]

thanks for the comments, and a good tip for a future video

[@arsenavdalyan51]

Right on time! I'm getting rid of banana Weber carb from my 1968 Volvo 122 and putting back a pair of SU HS6. Thanks a lot for the video

[@D3Sshooter]

Glad I could help!

[@LezOU]

Nice, I have the same AEM AFR sensor and gauge and mine fluctuates a LOT more. your tutorials are very good and very helpful !

[@darrenrobertshaw8030]

I now know a lot more than i did before episodes 1 and 2. Brilliant 👍

[@karljay7473]

Great videos and great looking car! I worked in a shop that remanufactured carbs back when I was in college. Did a lot of SUs, they are simple and very effective carbs once you know how to work on them. One other option for tuning is to get the O2 sensor. I have a predator carburetor on one of mine and I use an O2 sensor to dial it in.

[@matisse9267]

I recognise that bridge. It is at the edge of Oudenaarde and Kruisem ,pretty close to where I live. Wat een kleine wereld.

[@D3Sshooter]

Thanks for the comments, ja inderdaad... Ik woon in Oudenaade

[@andymiddleditch3855]

Very well made video, very informative and very useful.

[@D3Sshooter]

Glad it was helpful!

[@travelinben1966]

Your clear explanations and demonstrations have given me the confidence I needed to start to learn all the nuances of SU carbs.Thank you very much.👏🏻👏🏻Subscribed.

[@antoinemifsud4019]

Good videos (I saw part 1 and 2) very informative and hands on stuff, my Morris Minor needs a tune up !!! Very well made sir

[@jameshehir3334]

Thanks for an excellent video on tuning a carburettor. I have now ordered my Colortune as it appears to be the most economical way of tuning the carburettor. I had not heard of such a device but I am very impressed with the technique. I presume it will work with two stroke engines such as my chainsaw and hedge trimmer. I wish you well for 2021. Keep up the good work. It's invaluable to very many DIY persons. James from Dublin

[@D3Sshooter]

Glad it was helpful!

[@Mike-ys4sr2023]

I used the exhaust gas Analyzer for Emissions testing in Canada 🇨🇦 works great for Diagnostic purposes

[@D3Sshooter]

TXS for the comments

[@scottglover6100]

Really enjoyed this series of videos. Thank you.

[@D3Sshooter]

Glad you like them!

[@stewartpeterson9090]

Really nicely done, much thanks. Will apply to my new (old) MGB race car.

[@D3Sshooter]

Good to hear, a MGB GT ???

[@grayfool]

Brilliant. Thanks very much again. Terrific work.

[@D3Sshooter]

Thank you too!

[@bshnabel]

Excellent videos detailed and comprehensive, thank you

[@D3Sshooter]

You are welcome!

[@johnmcauley3317]

I am running out of paper taking notes. Thanks again!

[@D3Sshooter]

Perfect!

[@jimmielmholt]

Congratulation with the 30.000 subs. 👍

[@D3Sshooter]

Thank you very much!

[@alannunn1089]

Great explanation. Your Engish is good too Thank you!!

[@ShaunCymruDS8]

Very interesting. I have never heard of the colouttune method before. See through spark plugs.. now that’s a look :) Did you datalog after the changes to compare to how it was previously? It always amazes me the trouble you go to in order to share your knowledge, in this case going through 4 different methods and all for free on KZbin. Thanks again Steve.

[@grayfool]

Couloutune has been around for decades. It's a pretty cool way to set the mixture. And cheap.

[@D3Sshooter]

Thanks for the comments, indeed colortune has been around for a long time. I did do a log , and the changes were seriuos ( to the better).. Maybe I should have shown that .... Well I like cars, I like talking and I like to create video's... and to share and learn

[@redbarchetta8782]

Interesting. I've been trying to get my MGB tuned running duel HIF4s and the idle has been around 11.9:1 to 12.4:1 but obviously rich on the plugs. I will have to see if raising it to 13:1 to 13.4:1 helps. My only concern is I am not running a stock engine but modified high compression with a cam. About 9.5:1 or 10:1. This video does help as I have the same AFR gauge. Thanks for the great info. :)

[@D3Sshooter]

Thanks for the comments

[@StevesMachines]

Superb explanations 👍

[@D3Sshooter]

Thank you 🙂

[@MrJensdude]

Really enjoying all the video's on the mini as I'm just finishing my 1330 build with a HIF44. Could you share the AFR datalog after the changes? That way I can see what it should look like. Thanks for the interesting and detailed videos/lessons!

[@D3Sshooter]

Thanks for the comments, I will need to take that again as I deleted that file. As soon as I get to it I will

[@baioszisimos3367]

Excellent waiting for those videos... please in all carburetors when screw clockwise the mixture became rich?

[@D3Sshooter]

yes

[@kaindog100]

I’m in the process of doing this now. Thanks for the information.

[@D3Sshooter]

Best of luck!

[@bolti1000]

Brilliant video many thanks

[@vortigen1]

Hi, this is an excellent series of videos, thank so much, I am learning heaps. I have bought the same AFR you have but my mini has twin 1 1/2 HS4’s, what method should I use set the idle mixture screws?

[@RobinTheMini]

Thank you for a most useful video

[@D3Sshooter]

Glad it was helpful!

[@KompressorPete]

Thanks! Fantastic videos. After having a lot of trouble and having my twin SU HIF 6’s removed many times I followed your basic tips and vrooom. My Rover SD1 3500 v8 started right up and super great. However: after a quite hard ride with 3-5.000 rpm and full throttle plus a lot of heat both carbs spit out fuel from the overflow pipes. Why? Both needle valves are new and floats adjusted 1 mm from bottom plane when upside/down. Any ideas? Best regards - Peter Lundorf Denmark

[@Thereishope664]

Thank you very informative, I have triple SU's so a bit more difficult. I don't really find the colortune very accurate, the colour tends to fluctuate and is a bit confusing.

[@D3Sshooter]

Thanks for the comments , yes it is a basic tool

[@jrhouckok]

Great video. Any advice for high altitudes? I'm going on a rally in South America which gets up to 15,800 feet. I have a 1967 Volvo Amazon with twin SU HS6 carburetors, with KD needles. I currently live at 1200 feet altitude.

[@D3Sshooter]

As the air is less dense, you might need another needle ( thicker)

[@hosrow]

Fantastic video. You are awesome. I have a very close set up in the engine as yours, but my car does not sound nearly as smooth as yours. If I record it and send it to you, would you be able to tell me what may be the issue? I will order the needle and spring similar to what you did on this video and see the effect. I have very low power in 3, 4, 5th gear, so I may benefit from your changes. Here is my engine spec : * Head: KAD 12G940 ROAD100 CYLINDER HEAD * Cam: KAD100 Camshaft and single HIF44 * Carburetor: HIF44 BDK (current) * Lightweight flywheel * Pre verto clutch - performance clutch * 1275 Metro block bore to 1310 * 5 speed trans.

[@D3Sshooter]

Looks like a nice build...HIF 44 should be OK... just send it yes.... gears 3,4,5 create more load on the engine ( typical) and as a consequence the piston in the HIF should lift . two possibilities , 1 Damper oil not right or a spring that is to heavy... and potentially the needle type... Sure you have no vacuum leaks ?

[@hosrow]

@@D3Sshooter thank you for agreeing to receiveI a recording. How should I share it with you? Is there a way to attach to response to your KZbin video?

[@brianparkinson1594]

Excellent! Made to look straightforward when done in the right sequence. One question ... only necessary to add the air filter in the final test on the road, not during the carb set up procedure?

[@D3Sshooter]

No need at the carb prep stage, but for the idle AFR you can place it. I did not see a major change with and without. Of course that will depend on the filtertype itself ( how restrictive it is). For the road test , it must be inplace

[@brianparkinson1594]

OK, thanks for that!

[@minidoido1]

Great video. Very instructive. Did you get the plots after the tuning, to see the difference?

[@davidtomalty41]

Excellent video. If when tuning duel su carbs with these methods, is the use of an air balance gauge between the two carbs still needed ?

[@scottlucas4408]

Great video

[@billn5059]

I have a 61' Metropolitan that has dual SU's on it and am looking at getting a Colortune to help adjust the carbs since it seems to be running rich, but have read on a couple of forums that ethanol fuel can have an effect on how well it works. Since I am in the US and we have ethanol fuel my question is have you seen issues with it. Thanks for your video's. They are really informative.

[@sebaSs0o]

Very good information...I have a question, i have a Stromberg 175cd made in germany (it has a red cap) of my mercedes w123 of 1977, How can i remove the needle? i need remove it because it isn't vertical. I removed the side screw from the piston, and now i don't know what to do. So much thanks for your videos, greetings from Chile.

[@kennethtalbott2233]

some great info here. thanks.

[@johnclarke6542]

Personal I found you can tune the carb needles with a file, if your serious about tuning A series engine, you will need a heated inlet manifold the su will start to ice over without one

[@D3Sshooter]

Yes indeed, Thanks for the comments

[@charlesv20]

Another fabulous video! Keep on ;) How much afr do tou have on road with quick opening? What about going to a richer needle?

[@D3Sshooter]

Thanks for the comments, when pushing full open it drops to a 18:1 but quickly moves up to 12:1

[@charlesv20]

@@D3Sshooter , if we want to clean the 18:1 but the rest of the carburation is ok, what would be the solution : stronger spring? Is there an alternative needle? Or greater oil grade?

[@HSRacing29]

Hi, thanks for very good videos. Where do you have the sensor for the AFR ? I have mine where the gearstick comes up. The manufacture say 66” from the head. My dial is all over the place. I cant get i så firm as you. My engine is total rebuilt, bore, valve etc.

[@D3Sshooter]

I have it just at the end where the pipes of the cylinders meet in the collection point ( so just after that)

[@HSRacing29]

@@D3Sshooter Thanks for the info, i will move the borsch 4.9 sensor to that position 👍. Your mini sounds and runs realy good 👍

[@deangaryjames]

Excellent

[@D3Sshooter]

Thanks for the comments

[@GTE_Channel]

I would think the oil in your damper is still to thin. Even standing still the mixture should richen with the opening of the throttle.

[@D3Sshooter]

Oil is in my case ok... it all depends on the temp

[@DavidUKesb]

Many thanks for this as I am currently adjusting my carb on an ADO 16 Princess Vanden Plas. You mentioned the Colourtune changed colour during acceleration so should the correct colour reading be at idle or at higher revs? Cheers.

[@D3Sshooter]

Busem blue is at idle the correct color, acceleration needs to be lean to orange/yellow

[@DavidUKesb]

@@D3Sshooter So providing you have the correct colour at idle it's normal to change to orange/yellow with engine revs and doesn't mean the mixture is too rich at higher revs? Many thanks

[@TerminalMeltd0wn]

Very interesting video - is there much difference when it comes to tuning with an AFR with dcoe carbs?

[@D3Sshooter]

Its the same process... other tweaks

[@Fabi999able]

Hola. Necesito un consejo. Para mantener un régimen de aproximadamente 4000 rpm constante, ¿es conveniente un resorte mas pesado y corto o mas largo y blando. No entiendo lo del cambio de resorte.

[@D3Sshooter]

Thanks for the comments

[@hosrow]

I was looking through your channel and have a question. Is there anything you can't do? 🙂 You are Man with many talents. Regarding tuning a hif44 carb, I am following your video to install a AFR Guage. Getting really frustrated with the tunning. I either get plugs with black soot or bone while, never the rusty reddish color. My question is do you recommend using petrol without ethanol for mini?

[@D3Sshooter]

If you can yes, ethanol is not a good thing at all

[@paulhotson5820]

Did you use the yellow spring in the end or back to the 4.5oz ? You could have used the red spring and used a thicker oil like 20w/50 in the dash pot. Very informative thank.

[@D3Sshooter]

Thanks for the comments, yes I did

[@AleksandarMiladinovic]

Thank you very much for the excellent information. I just have a question, in one of the videos, I saw you placed O2 sensor at the end of the exhaust and measured the voltage with an oscilloscope. I know it was a narrowband O2, but I wonder if it is possible to use wideband at the end of the exhaust to tune the carburettor? I believe that the readings there are a little bit different, probably more O2.

[@D3Sshooter]

That is correct, there are rules for the placement of a Wideband sensor.. typical with a minimum of one foot away from the cylinder head, before and muffle. Its importend that the sensor get the real O2 values. The further away from the engine the larger the error becomes due to the O2. Besides the fact that you need a certian temperature. The measurement I did was only to show how these sensors work and the kind of signal they produce

[@AleksandarMiladinovic]

@@D3Sshooter Thank you!

[@Scrubworks]

I have a question, I have a matched pair of HS2 carbs that I'm thinking of rebuilding. They're off an MG 1100 originally (AUD 69), and the SU catalogue says the left hand carb is fitted with a 4.5 ounce spring, but the right hand carb only should have a 2.5 ounce spring. What's the reason for mismatching them like this?

[@D3Sshooter]

Thanks for the comments , to be honest I don't know . In fact that is very strange. What is the intake manifold like ? Springs are typical selected while driving the car and checking the performance as shown in one of the video's. Maybe engine has different compression at specific cylinders ( that could be , and they matched the springs for the best performance).

[@Scrubworks]

@@D3Sshooter The manifold is the stock MG one, it's a crossflow design that shares both intake runners via a tube joining them together. I think the reason might be to do with air filter design and flow into the carbs, as the carbs are off a transverse engine originally like in your Mini. I will be fitting them to a longitudinal engine (Morris Minor) so they'll have a lot more breathing room, so I'll probably put matching springs in.

[@cruiseoveride]

In the video you say under load it would run richer. Why is that? 27:00 Would 2k rpm cruise in neutral be different from 2k rpm under load in terms of AFR?

[@D3Sshooter]

Under load , there is more vacuum as the engine is gasping for air, so the airspeed increases and so does the venturie effect. Yes it would be

[@nexcode9608]

Super erklärt!

[@D3Sshooter]

Danke

[@GTE_Channel]

Well made, my compliments. Is your in car rev counter a little bit off? Idle rpm seems around 500?

[@D3Sshooter]

Thanks for the comments, yes it was, needed to restrap the dip switches in the back

[@classic1989mini]

The graph you shown with the needles on, is this a web site. Could you say which it is?

[@phatlaz1974]

Thankyou

[@rogerlittlejohn475]

What causes run on or diesel in?

[@bobwgower]

What were the AFR readings while cruising on the open road at constant throttle ? On the highway at speed for example.

[@D3Sshooter]

I have a 14.8. Of course that depends a bit on the speed and wind.

[@gerhardnowak3700]

Please can you tell me where are you buying the Su Parts.

[@D3Sshooter]

In the UK Burlen..

[@vintage76vipergreenBeetle]

👍

[@jonesboy2004]

Great video. What is the richest so lowest AFR you see once happy with tune on WOT? Mine is 14ish on cruse but will drop to a low as 10 briefly on WOT before coming back to around 11.5 to 12 is this normal or do you think I need a weaker spring or needle? Thanks

[@D3Sshooter]

Looks good to me, very similar to mine

[@MultiDopper]

how to read spark plugs on a classic mini next xD

[@D3Sshooter]

Thanks for the comments, maybe next time

[@baradonna9205]

That engine sounds like a cat purring.

[@D3Sshooter]

Thanks for the comments, and yes it does

[@rong.7768]

Adjust your steering wheel, not straight... 😁

[@D3Sshooter]

Thanks for the comments

[@jasontucher7011]

Mr. Kelvin isn't taught in the U.S. highschools. To learn chemistry, you have to pay many thousands of dollars for university. What Americans know about science is pathetic. I hope we get universal education and healthcare soon. Thanks for showing the sparklætor, it was very cool.

[@D3Sshooter]

Thanks for the comments, I did not know that.... I was under the impression that this was basic...

[@colemadad]

Excellent

[@D3Sshooter]

Thank you! Cheers!