How a 2 Stroke Carburetor Works, Fuel Pump & Metering

[@JustSendItSaws]

This might be the single best KZbin demonstration video I have ever seen! All I can say is wow, you have really knock this one out of the park! Major props on designing and fabricating that demo carb! The time and thought you put into the model is absolutely astounding! Bravo sir, bravo!!!

[@jbbolts]

I instantly subscribed as soon as he pulled out the 3d printede model 😀

[@jimmyhoward3015]

Amazing great detail thank you sir !

[@dawsonjd247]

I'm saying... He definitely knows his business

[@burnfossilfuels2]

Really great video. Thank you!

[@yusayres2505]

Great! Great job indeed👍🏽👍🏽👍🏽

[@rayadelic4327]

MAN! You deserve the Nobel prize award. This tutorial should be shown in all mechanical schools worldwide. Very well done.

[@ericfillmore7262]

Unbelievable. Just absolutely mind boggling the way that you built that full-size model. I’ve been tinkering with these carburetors for about 30 years not really knowing what the hell I was looking at but now I completely understand them inside and out thanks to you. I’ve watched this video about four or five times. Absolutely amazing.

[@garyroberts2863]

This has to be one of the best instruction videos I have ever seen

[@shockalotti]

Holy moley. That's the best carburetor explanation in the history of mankind.

[@TheNoisePolluter]

That is the coolest 3D print I've ever seen!

[@christophersheppard1747]

I am nearly 70 and it has taken me until your unbelievable video to understand the "simple" 2 stroke carb! your printed model just blew me away! Thanks for the incredible amount of time and effort you have put into this Jay, I am forever grateful.

[@DonAntoniodetucum]

Great demo

[@stevebrankin9582]

Amazing ! Thank you !

[@1990Co]

Dude this deserves like, national recognition. This needs to be used in any educational setting for mechanics. Best video hands down

[@windsurfingphd]

Walbro should adopt this video as their main (and only) tutoring source to educate their engineers. I am a retired computer engineering prof from a local university, and I can vouch that this is an amazing piece of work done by Mr. Gould. I searched in the internet to get a good understanding how a Walbro carb worked because I wanted to learn about RC gas engines, but couldn't find anything substantial, just bits and pieces of info published by people who didn't know the entire mechanism. Finally, I started examining Walbro diagrams on Walbro website, trying to figure out the exact mechanism. I found out most of these diagrams were sketched for people who were already very familiar to Walbro carb, but didn't make too much sense to me (or novices that don't know too much about carbs). I am glad I stumbled across this video. Thank you again.

[@philliprsa]

One can not watch this video and not leave a comment. The sheer amount of effort and detail that went into this project is amazing. This is the best video on the internet to explain the workings of a two stroke carburetor. Well done to the creator of this props and video. This should end up somewhere on a site where they teach the basics of petrol engines. Yet again well done!

[@vennic]

Oh really? I'll show you not leaving a comment! oh wait.......

[@TheLawnmowerLady]

This is hands down a most awesome video. The time and attention to detail is astounding. These carbs are so small, and so difficult sometimes to understand what is going wrong, but now the mystery is so clearly explained. This video should be a requirement for any one working on small engines. Thank you sir.

[@WilliamFrawley]

Thank you! Many, many hours spent with precision measuring equipment and a microscope to get each part exact.

[@haneyoakie14]

A agree with Stella and Kenny. This is an awesome explanation. Thank you for your excellent content

[@Gssmallenginerepair]

I agree 100%

[@cappablecannon1824]

agreed

[@StevesSmallEngineSaloon]

@@WilliamFrawley Would you mind if I promote this video on my channel? Everyone needs to see this!

[@lakerdigital]

This guy deserves one of those film awards they give out in Hollywood.

[@terryshaw1138]

You have gone to unbelievable lengths to demonstrate the principle of this carburetor. I take my hat off to you. You are a real engineer sir !!!

[@Jerkysan]

I'm late to the party but this literally was one of the best explanations I've ever seen. I can't believe you took the time to make that huge 3d printed model. It's all amazing work!

[@glenn255]

I could write a page full of accolades and praise for the work you put in to create this video - Or just simply say, Thank You so very much!

[@erickavanaugh6015]

This has to be the absolute best explanation I've ever seen. If I had been able to watch this 25 yrs. ago it probably would have saved me a lot of head scratching as I learned this on my own. Thanks for sharing. Love the large scale printed carb.

[@nevergiveupever1069]

Thanks for taking the time and effort to create a video that shows you are a kind man

[@capt.chrishayes7543]

Agree this should be one of the how to understand 2stroke carbs, in schools everywhere, hats off to you sir!

[@martincrean7993]

I must watch this a few more times to let it sink in fully. All my life I have been almost blindly opening up carburetors and trying to get then functioning again. Sometimes with good results and sometimes with failure. I'm 62 now, pity I didn't know all this when I was 22. But however I have a walbro fueled chainsaw that dies out when accelerated and perhaps I can put this information to good use tomorrow. Thank you very much for this most informing tutorial !!

[@paragyver]

This should be the gold standard for any You Tube instructional / tutorial video. You have done a great job explaining in very clear terms and your 3d prop is an absolute work of art. Thank you for sharing this video.

[@micko1404]

this is by far the best explanation on how these little carburetors work. I was aware they had an integrated fuel pump but didn't know it all happens on one side. Excellent 3d printed model too!!!

[@randphong]

Awesome! This is the best teaching video on you tube. Straight to the point with no unnecessary ''Fluff' and no beating around the bush. No distracting background music. Appreciate all the work in 3D printing the parts. YOU TUBE, are you listening or seeing this? -GIVE THIS GUY AN AWARD.

[@larryoakley]

There are tons of KZbin videos about how a two stroke carburetor works, but this is by far the best one. That upscaled model is a great help to understand the principles . Thanks a lot !!

[@quinnhaynie7767]

Can you imagine having the knowledge, curiosity, tools, skill, and eloquence to be able to complete a video like this? I’m blown away and if this creator hasn’t already been snapped up by a major hardware company I’d be very surprised.

[@ed3548]

Hands down , no competition, the best video demo on 2 stroke carburador. This fellow deserves the Smithsonian Award for Ingenuity? Deemed “the Golden Globes of Intellect,” the American Ingenuity Awards honor individuals across nine wide-ranging categories: Education, History, Life Sciences, Performing Arts, Physical Sciences, Social Progress, Technology, Visual Arts and Youth. And this gentleman for sure deserves one. 🖒🖒🖒

[@neiljarvis8911]

A phenomenal lesson in chainsaw and weed eater carburettor principle and practice. Your models and props are better than anything I have ever seen before as teaching aids and your knowledge and calm systematic explanation is easily understandable. The preparation invested in this short class is mindblowing. Thank you so much, if I had received tuition of this quality at school it may well have changed my life.

[@Thfeyhvfdetyhbvcd]

I just HAVE to comment again! I knew virtually nothing about my gas string trimmer until I watched your video. Now I feel that deep dirty carburetor secrets have all been revealed. I understand what makes it tick!!! Thank you so much!

[@dale_ch]

Absolutely fantastic tutorial and 3D printed models! I'm Technical Director of a company that manufactures 3D printers and the time and effort put into Jay's 3D models is enormous, hours and hours of work needed to design and produce these models. Jay, you're a credit to engineers everywhere and your tutorial is 5* Thank you! PS. I repaired my chainsaw because of your detailed explanation of the debris gauze at 6:42 on the tutorial - mine was so blocked up that I thought it was a 'plug' and not a 'gauze' which it proved to be after closer inspection and cleaning !!

[@terrykohlman7355]

The BEST(!) video description EVER of how these small 2 cycle carbs work. Thank You very much for all your hard work, (and many hours of 3d printing)

[@MontyPrather]

As a former Auto Tech instructor at the college level, That was amazing.Not only did you answer every question I had, I learned more. You also kept my attention going to gain more knowledge. I loved the props you used. Well done sir.

[@MarkAAshdown]

A very professional explanation of this cube carburettor. Please help this guy out financially if you can.

[@tomc9750]

Best teaching video I've ever seen on any level and I've been doing this for over 30 years kudos To this guy you can't ask for anything better than this you can't even pay for classes this good

[@nicholascrosby6438]

I’ve been teaching for almost 30 years. And this demonstration is just epic! Unbelievably good.

[@hanson-david]

I cannot appreciate enough the effort you have taken to explain the operation of 2 stroke carburettor. Amazing work. This is a 'gold standard' training video.

[@guyandrewmartin]

All I can do is to agree with all the other comments. This is a fantastic tutorial. The large scale demo is a work of art in its own right and the crystal clear explanation you provided with it makes this video one of (if not the) best I have ever viewed. Thank you and well done.

[@ryanlynch3579]

I've had a general understanding of and worked on small engines/carbs my entire life but have never seen such a comprehensive explanation and so efficiently done. This was flawless. Nice work 👍

[@danielgutuescu5321]

I didn't expect this level of clarity and professionalism. English is my second language but I designed closed to 100 machinery, machine tools, injection molding machines and tooling and wrote most manuals for them and I did not even reached 75% of quality job as you did here.

[@swssws9803]

Not only do you understand and explain carburetors very well, but you are an artist making those models! Many thanks!

[@andesmallku]

Best educational video ever, thanks a million to the creator.

[@indy9316]

The Gas remote control , cars, planes , helicopters and boat enthusiasts would be astounded to know this much knowledge and they could completely appreciate the detail of skill your work and explanation efforts you have gone too. Thank you and God bless your talents you share. Wow...

[@benjaminc.3851]

The final montage of photos was the cherry on top. This video should be put into the Library of Congress. This is a national treasure of a video. Subscribed!!!

[@steadyeddie7453]

You put my faith back in KZbin training videos. Awesome detail. Your explaination of the fuel delivery solved a lot of mysteries. Also, don't forget the other 2 holes under the welch plug for the low speed side are progression ports. They bridge the gap between the low speed (idle) and high speed. Thank you for an outstanding job. Cheers

[@DavidLee-fy7rd]

That was the most comprehensive video I’ve ever seen.

[@TimsToolTime-bx1es]

100%!

[@Jonathan-vo1vt]

You are a legend and deserve a medal. Thank you for the time you put into this. When you pulled out your printed model I was floored at the level of detail and construction. Thanks to you I now have a better understanding of this highly complex part.

[@timc3600]

Thank you. I've been stripping these down for a couple of years on my garden equipment and just cleaning them the usual way and blasting through the holes with carb cleaner and compressed air and fitting new consumables, then most of them work , but now I've got a difficult one to fix where that's not worked and after watching this, I know where the problem is likely to be. This weekend, I'll be out there taking a closer look in the affected area. Update after a bit of time on the healing bench, its fixed !! The idle jet passages had a partial blockage

[@marcusrf7]

I totally agree with "The Lawnmower Lady" and "David Mansfield". Your desire to educate others on something that is very hard to find information on is astounding, and your attention to detail and accuracy is almost beyond belief. I want to thank you for your efforts. I plan on using 2-cycle carburetors on 4 cycle engines, because the 2-cycle carbs can be set up as down-draft instead of the normal side-draft, allowing a longer intake manifold for added fuel mixture velocity. I was concerned with how to operate the pulse fuel pump, and to complicate matters, I confused the fuel metering diaphragm as the fuel pump. I plan to use a stainless steel tube inserted into the exhaust manifold so that the high velocity exhaust gas will create a vacuum in the SS tube which will go the the fuel pump pulse tube/entrance and pull the diaphragm against a spring to complete the push-pull action. After seeing this video, I now know that I can do it. Thanks again!

[@sportscarclinic]

Thank you sincerely. After 45 years of tinkering with these things, I can say that I now, finally, have a pretty good idea of how they work.

[@NJUSA36]

More people need to see this video. Your illustration is wonderful!! The model you made must’ve taken a very long time to make but was well worth it!! I hope there are other videos with different types of carburetors on your channel. I believe you have explained this very well. Thank you

[@SpiralDogma1990]

That carb is just Amazing. Great work!

[@jimgraham4700]

Thank you Jay for all the time and effort you put into this amazing video. I am 67 and have been tinkering with these carbs for a while now and could never understand how they worked, until I found this video!! Thank you so much again!

[@patrickshaw8595]

These are "Demand Regulator" carburetors. They are not necessarily specific to 2-cycle engines. Tecumseh made tens of thousands of four cycle engines equipped with them. The 1958 Brown carburetor was the first of this type. The literature on them mentioned that they were a simplified Bendix RSA aircraft pressure carburetor. In 1960 Tillotson bought the rights to the design. In about 1968 Walbro began manufacturing these "diaphragm" (as opposed to "float type") carburetors - and they worked really well. One reason they worked so well was that they incorporated a "main fuel discharge check valve" to prevent air being sucked in the main discharge when idling. For years nobody minded air being sucked in the IDLE discharge when the main was pulling high suction. Later Walbro and others (many if not most carbs used on Stihl) incorporated idle discharge check valves as well. (To my knowledge no idle check valves were intended to disassembled and repaired) A big problem with these carbs is the diaphragms become stiff and "oil can" in and out taking a set first one way and then the other. Walbro now has kits to retrofit clear diaphragms guaranteed to never stiffen (but they must be used with a matching super thin spring steel flat spring - it comes in the kit) Hardly any mechanics know that you should know how to check the piston rings, cylinder base gasket, crankshaft seals and even the reeds/piston skirt valves for air leakage if your initial disassembly and renewal of gaskets and diaphragms does not yield good running. It's like this kids: 1) Compression (which includes crankcase compression!) 2) Ignition - which includes spark plug. 3) Then if you have an engine with a dry carb in place that also EAGERLY burns it's prime - You can get it wound up and un-pinch the fuel line and see if you can get the carb to take over from the hand (squirt bottle) priming that you are doing. YOU ARE WELCOME

[@ironfencer3957]

Amazing job on everything in this video. Your explanation is clear and understandable, and the 3d model with the different view points was incredibly helpful. Thanks for putting in the effort to make this; it feels awesome to really know what I'm looking at

[@DrRock-luvzBella]

I've looked at tons of 2 cycle carbs videos for various answers. If I'd watched this one first, I'd have a lot more time on my hands right now. It don't get any better than this...

[@tomasortiz-potter8917]

Honestly this video left me speechless..where has this been all my life!? You did an absolutely amazing job articulating every detail and making it so easy to understand... Thank you for making this impeccable video!

[@alfonse4595]

This is the coolest thing ever! I basically knew how a chainsaw carb works, but the fact that you made a giant model is so awesome! The cut away of the tuning screws is particularly interesting for me. Edited to add: EVERTHING is perfectly color coordinated too, even the shiny crome metering side cover!! I can't believe it.

[@gunnutmike]

This is without a doubt the best KZbin video on how anything works that I've ever seen! The 3D Printed models are amazing and they (plus your excellent and easy to follow narration) make it easy to understand exactly how these carburetors work. Thank you for all the time, effort, and skill you put in to making this amazing video! I am now subscribed.

[@hansvonwitzlan3582]

If this gentleman had been a teacher when I went to school, there is no doubt that I would have payed better attention. I had subscribed before he had the small carburator laid down on top of the 3d printed large one.. I thank you for this

[@johnsonlong1272]

By far the best demonstration of how a 2 stroke carburetor works you put a lot of time and dedication into that thank you sir. This should help understand these buggers.

[@j.m.5995]

Wow. THIS is the best video explaining the operation on theses types of carburetors that i have yet to come across. Those large models make it so much easier to grasp the concepts and makes it possible to very easily visualize whats taking place and what could possibly foul the system

[@TheCleoBunny]

Wow! You are a 3d printing legend!! Thank you so much for taking the time to make such a detailed video. I really appreciate the time and effort spent making this demo. Thank you!

[@michaelturocy3319]

I knew bits and pieces of how it works, BUT this explanation and the cutaway model, your detailed explanation cleared up a lot of grey areas I had for years. I'm angry that I've spent so much time in years past watching videos without the detail that you presented. This video should be the number 1 search result on YT. Thank you for your efforts and what a fantastic model you made for this!

[@donhaywood6542]

Dang Jay, This is just fascinating! I applaud you for your dedication and the 3-D version is spectacular. I'm working on just this type of carb right now. It is great to understand it more thoroughly. Thanks very much.

[@peterwaterman234]

I wish I had seen this earlier, it would have saved me from watching dozens of other videos. Best tutorial ever!!

[@ericanding]

You really put a lot of time into this! Thank you so very much for the demonstration. That was very helpful! Incredible job! This was by far one of the best KZbin videos I’ve ever seen! Amazing!

[@rhbofwcc]

I have never understood carburetors and my work on 4 cycle carbs has kept me away from the smaller ones. This video shows me I shouldn't have parts left over with 2 cycle carbs and your explanation really explains how they work in an understandable manner. Thank you so much. Now for your model. The amount of work to produce it seems fantastic. It really helps with your explanation. The time spent producing it was worth the work as it is large enough for us to see what is happening. Thank you for your time and effort.

[@erican442]

I just want to say this is the best educational videos I've ever seen on KZbin and I watched a lot of them. I don't normally leave comments but I could only imagine how much time you put into making up that mock-up carburetor and video editing for making this video. With out a doubt Great Job give yourself a pat on the back.

[@jmanatee]

This is hands down the best most detailed explanation of how a two stroke carb works Excellent job.

[@rahulsutar9970]

This is the best video I have ever seen about the demonstration of working of a carb. It is so very well explained. And the time and effort you have put in to 3D print the model and its corss sections just blew my mind. I am really very thankful and appreciate your time and effor that you have put into this single video. Simply fantastic !!! Thank you !!

[@bentranch1895]

Extremely well done. You take teaching to a new level with that 3-D printed model. I now know where to look to solve my chainsaw carburetor "fuel leak out through the exhaust port while sitting and not running problem". Thank you.

[@justinb1590]

Good sir - bravo. You actually create value for the rest of us. Much appreciation for sharing your talents and time.

[@SiteReader]

Those enlarged 3-D printer models are brilliant. This is the first time I got any real understanding of how the tiny carburetors on 2-cycle garden equipment work. Lots of repair-tip videos out there, but nobody else takes the trouble to give the overview and explain the details of the fuel delivery cycle. For those who want to understand what's really going on inside these little marvels, watch this. Chinese factories may be able to turn them out today for $20 (I just bought two), but it took 150 years of creative thought and engineering to design and develop them. Appreciate that the next time you pull that starter cord.

[@elliotnauert1108]

Hi Jay, excellent work, thank you! Would you be willing to make your 3d model files available for others to print their own? These would be great training aids for my wildland firefighters.

[@YvanPeelaers]

The way you made the enlarged parts and cutaways is amazing. It really helps to understand the different parts and the way it works..

[@phall9195]

Fantastic explanation and awesome 3d printed model!! Those little carbs are quite complicated. Whoever figured all that out was pretty smart. Thanks for the video

[@cdelatorrejr]

Amazing explanation of a 2 stroke carburetor. The use of the large model with cutaways helped me tremendously understand how it works. Excellent job!

[@troywayne8759]

Honestly, one of the greatest youtube videos I've ever seen. I've been working on small engines for years, learning everything I could, but I never truly understood the inner workings of a 2 stroke carb. This is amazing.

[@jesusestrada5543]

Now he needs a giant 2-stoke engine to complement the giant carburetor. Seriously though, this is an AMAZING explination on how a diaphragm carburetor works, without the need for me to take apart mine and then never figure out how to rebuild it. So thanks for your effort on making this whole video man!

[@andrewkoehler5386]

Excellent Teacher. Plain, articulate, zero “filler words.” As for the demonstrative you’ve created? It’s hands-down beautiful. Seriously well done Sir. Your passion is contagious and inspiring.

[@WilliamFrawley]

Glad it was helpful!

[@drmikeyb1]

What an awesome video. I'm a 57 year old disabled vet trying to learn a new trade with 2 stroke engines such as weed eaters, chainsaws etc.. I've gotten my bronze through Stihl but have a ton to learn. I believe I could sit down with you and ask 100 questions. Thank you for sharing sir.

[@thepragmatic6383]

The art of dissecting a carburetor, as a cardiac surgeon would with a human heart. A video of surgical quality, precise and perfectly documented. I understand how these tiny carburetors can be built with computer controlled machines, but how they made them before the arrival of these modern machines remains a mystery to me.

[@donmayberryjrsOPE]

I've been rebuilding these carburetors for over 45 years and now I fully understand! THANK YOU!

[@9000000football]

This is outstanding. Never saw anyone explain something so well. You should win a KZbin video of all time and be in their hall of fame. Thank you!!!

[@LusiTron]

You're my new hero!!! I can't believe you recreated that carb perfectly to scale! Man, respect! Now, I can't wait 'till you recreate the rest of the engine, so then you'll have the most GINORMUS 2 stoke weed wacker engine in the world!!!

[@lmpdec]

Congratulations! In the 3D gtaphic animation era, you created an amazing state of the art upscale real model! Beautiful educational video!!

[@ВалераДемиденко-ц9п]

Самое наглядное пособие по работе мембранного карбюратора и лучшее, что видел в интернете, благодарен автору за его творчество и обучение.

[@baydonwhite1479]

I have to give it to you. The time, preparation, and dedication for this video are unbelievably amazing- not to mention the 3-d printed model. Thank you for taking the time to perfectly construct this demonstrational video, sir.

[@Markko1986]

Massive respect for making the upscaled models!

[@Antiqueexcavator]

Now I understand how the pull start works as well! I consider myself an expert after watching just once. I’ll soon be a genius as I watch it again. If this guy was a teacher in any of my classes I could have really been somebody. We need to find people like him to fill our classrooms nationwide.

[@tombarton1]

Incredible....KZbin should give awards for instructional videos. You would win. Thank you.

[@Billster1955]

Most amazing instructional video I've ever seen on these little carburetors. They're tiny, but there's really a lot going on. Thank you sir.

[@wmwinkle]

Durn! I've been rebuilding carbs for years and this is the best break down I have ever seen by far. It has given me a new understanding of things that can go wrong and how I might fix them. It also lets me see what I should expect to see when doing things like squirting carb cleaner in the various holes. Walbro carb are very common and the clones work just the same with minor variations. I owe you my thanks. Next time I lift a brew I'll toast you.

[@JamesRalston-kp6ny]

Thanks for this. I salute the thoroughness and patience that went into building the demonstration models! A brilliant job!

[@wesbosse5708]

Wow! This was the best description I've ever seen. You just made me a smarter man. Now when I have carb problems I'll know exactly what to look for!

[@michaelpiecewicz9748]

Well that was as good as any carburetor lesson as I have seen in my four decade career! Thank you. Also, yes I subscribed

[@Sammenluola]

Thanks to this incredible video, I now know the life of a two-stroke carburetor. My humble thanks sir! This is what the internet is for.

[@Zooks4]

You, Sir, Have gone above and beyond in your presentation ! I've learned more from watching your video than all other videos I've watched to date. Thank yo0u for your good work! John Jaramus

[@donhalliday6447]

I am now a fully qualified 2 stroke carburetor technician after watching this video! Thank you my good man. lol

[@markkulyas2418]

Now this is how you teach people how things work, every detail covered and you speak at the perfect speed so we can understand what's going on. I have watched many videos on 2 stroke carbs and your video is the only one that explains every detail of how they work. Thank you so much for taking the time to do this for us. 😀👍

[@astrotimber8925]

Dude! Best explanation I've seen. Must have taken a lot of hours to put this together. Thank you! The only thing I missed was where the low speed fuel comes out into the throat of the carburator.

[@RollingEasy]

Thank you.... This is absolute excellence in teaching, in instruction, in just plain telling it as it is.... I'm 72yrs old and I learned something today. Very well done and this sets a standard that's hard to better.

[@dandu9817]

this is a awesome video. The clearest description i have ever seen. I would recommend more people to review it. This also helps me to understand the fuel lines routing. thanks!

[@bpd231martinko9]

What can I say that hasn't been said in the comments below. I hope that when you have some free time from your day job as an engineer (I'm assuming that's what you are) , that you're spending a day or two a month teaching at the local Vo tech school. The world needs excellent instructors like you. Thanks.

[@mitchgig]

Ya, as others have said this is the best cutaway and explanations of small engine two stroke carbs I think I've ever seen. Really good job, you really took some time to do this.