Briggs and Stratton Carburetor (How it Works) (by Craig Kirkman)

[@TheRepairSpecialist]

Hi guys I just wanted to Introduce to you my other Channel "Kirkman's Academy" - which i'm just getting started. It's a go-to channel for simple explanations for hard to grasp subjects such as physics, maths and chemistry etc. Here is the link: www.youtube.com/@kirkmansacademy/videos . Thank you so much for looking, and if these topics interest you then I hope to see you the there. Many thanks indeed. Craig 😊👍

[@trainmaster0217]

This is a masterpiece of teaching how a lawn mower carb works. So clear even I could understand it and that's saying something. Your are a great teacher. Enjoyed every second of it. Thank you.

[@orweyztungchiu5819]

Been fiddling around with small engines and carbys for many years now and for the first time thoroughly understand the workings of a B&S carb rather than just intuitive. Love your commentary and detailed graphics!

[@shadowghst7704]

This was without a doubt, the best, explanation of how this type of carb works. It all makes sense to me now. The animation was beyond top-notch, and helped so much! Thank you for all the effort that went into this!

[@aiklua1069]

Having just service my carburetor, and it still did not work, saw your description on the working in detail it will make the servicing a lot clearer and sensible. Fantastic explanation in steps, totally invaluable even for a simple carburetor, it is a fantastic design, simple and functional. Thank you for the wonderful explanation *****

[@terrystover7365]

I've been working on small engines for many years and this is the most informative video on carburetor function I've ever seen. Absolutely great.

[@dennislockhart7290]

5 yr 4444t tr

[@TYEGaming]

Yeah definitely better than other videos, very clear and detailed 👍

[@2003cinman]

What an amazing, well illustrated, patient and informative video - thank you so much for sharing this with everyone 😊

[@ChefGourmet]

Incredible video. I have never taken a physics class in my life nor do I know much about engines, but I understood this video perfectly. Thank you

[@TheRepairSpecialist]

Thank you for your really awesome feedback. I really appreciate it. Craig 👍

[@TheRepairSpecialist]

If you do fancy knowing what is going on inside the Carb when you make these adjustments as well then this vid of mine will explain this. Thanks again. Craig : Chainsaw Carburetor Screw Function Animation | Real Chainsaw Sounds | Understanding Tuning Explained : kzbin.info/www/bejne/oYXPqmd4jtuUq68

[@scottrogers9398]

Sir, I must commend you on the most thorough and detailed delivery of information on this type of system I have ever seen. Well done!!

[@timlist4173]

Thank you for the indepth explaination. As a technician (electronic), i am quite detail orienated and this is a perfect explaination. Well done.

[@jacucha5767]

Saved my 2 lawnmowers that were destined for scrap thanks to your fabulous tutorial. You have done it with precision, patience and magnificent graphics. Excellent work. Thanks mate.

[@rogerking7258]

I have over 40 years experience tuning Weber DCOE carburettors but yesterday when my mower would start but not continue to run I was perplexed indeed. Where is the fuel pump to lift the fuel? Where is the float chamber? Well you've just made it crystal clear and I must say what an ingenious idea it is to use the inlet pulsing to run a diaphragm pump (although I guess it wouldn't work on multi-cylinder engines) and remove the need for a float chamber. I had assumed that the priming bulb merely pumped fuel in manually as an enrichment device to get the engine started, but I now know that it is also purging air out of the main fuel circuit. Finally, I like the way that the second tube connected to the main jet draws in air to act as a crude emulsion tube. So ingenious, but like all great devices, so simple; I just needed a little help to understand it. Looks like I probably need a new diaphragm. Many, many thanks.

[@frankgruendel2286]

The best explanation of a carb function I've ever seen!

[@Burnsomatic]

Excellent, clear, thorough tutorial. A pleasure to watch this. I'm also very glad there is no music in the background -the voice is all we need. I see many things that are ruined by background music on KZbin. But this was excellent in many ways. Thank you.

[@bobcarry4820]

Your graphics were well worth the time you spent to create them. I knew how a carburetor works but now I really know how a carburetor works including the little passages which I always wondered about. Thanks.

[@bassmith448bassist5]

I've been fooling with Briggs engines since I was a sprout (56 now). I learned these carbonaters from a wise old man named Johnny McFarland. He never taught a master class like this!!! My hat is off to you sir. I do think you could trim your video for time but overall, if someone else asked me where to look for info on these little carbs, I'd send them right to this video. Job well done I say. Cheers from Florida USA.

[@bassmith448bassist5]

Wow!!! Thanks for tagging my comment. As a guy who's spent most of his misspent youth (and into middle age) poking at the working bits of engines big and small, I've seen a lot. I've thought a lot about doing KZbin videos and then I thought, Naahh!!! Who'd take this guy seriously??? You explain things in a way that even a non mechanic type person could watch that video and understand how that carburetor works. It really is a cool design. No moving parts, and as long as you have vacuum it will pull fuel. I still have one on a go kart that is of aluminum and has a choke instead of a primer. Works just fine.

[@scottritter8552]

I cant imagine the work that went into this video. Very well done!!! Thank you for your time.

[@bradleycrosman1685]

I am 65 and this is the best explanation, I know it took many hours to put this together, many thanks for your hard work.

[@mikes9939]

I work on all kinds of old cars with carbs and know all of them very well but the Diaphragm carb was a type that I never really took the time to learn. This video has done mankind the biggest service since the invention of the wrench. It is the best tutorial I could imagine anyone doing and the author can be proud of this accomplishment. Many thanks for making this.

[@grantwestcott8771]

Absolutely BRILLIANT. Thank you for the great effort and time to make this video.

[@markmark2080]

Excellent, I was salvaging a thrown away lawn mower and "went through" the carb not knowing anything and couldn't get it to run. Now I know, what a difference a little knowledge makes, thanks.

[@terrydix3768]

Excellent - a lot of work went into producing your video, now after a decade of owning the mower and replacing the diaphragm I understand what it does . Many thanks.

[@TheRepairSpecialist]

Thank you so much for the nice feedback. I really appreciate it. Craig

[@michaelslee4336]

Absolutely top effort on this, excellent work. I had my 4 stroke brush cutter slowly bog down more and more and finally took it for a service and they installed a new diaphragm as it had gone hard, now I know the intricate details why. Also had my mower not run well and the bulb had sucked in, very dirty air filter was the cause and again I can see how too much vacuum would do that. Thanks again.

[@figjam5181]

The great thing about this video is we have a explanation on how this carburettor works. Nearly every other video about this carb talks about how to replace the the diaphragm and gasket and how to clean it. Basically any monkey can do that. It's understanding the working principle to repair it that matters otherwise you don't really know what you're doing apart from replacing things and hoping for the best. Great video!

[@henrytupper6959]

This is the best description of how anything works that I have ever seen. I have had a very basic understanding of how they work since they are not gravity fed like other carbs I have repaired. But this tutorial shows every detail. My Brigs was bought as a reserve mower almost 30 years ago since I like older Lawn Boy engines. I just use it on occasion , however it has always started first pull. Still does but it will not run at full speed now so I need to do a carb clean/rebuild. Thanks very much. Henry

[@stevenmartinez5531]

Your repeating was welcomed, it helps us slower learners! Thanks.

[@chrisoxenham10]

I think for sheer effort and detail you deserve a A++. What a brilliant and very good video this is. I enjoyed it from start to finish and ‘tip’ my hat to you Sir.. very well done!

[@joannagrimmer]

Incredibly helpful, Craig. All your trouble creating these diagrams and animation explain so many reasons why a mower will not run right. Many thanks.

[@jerrykast7713]

I want thank you for this informative video. Its always refreshing to find someone who knows what their talking about.

[@jeffd3844]

Very informative, thanks for posting. I have one of these on a 3.75 hp Briggs & Stratton lawn mower engine. I've had it 27 years and never had any problems. I didn't use it much, but I never had the carb apart and never had any problems with it.

[@atomizer2665]

The detailed explanation of how the primer bulb works was a godsend for diagnosing the issue of the primer bulb not pulling fuel. Many thanks :)

[@TheRepairSpecialist]

Thank you so much 👍👍👍👍

[@atomizer2665]

@@TheRepairSpecialist Is there a trick to getting the primer bulb retaining ring to clip into the slots? I can get one side in but not the other :)

[@markparee99]

On behalf of all my fellow 'shade tree' small engine hackers, I salute you! Very well done!

[@cybair9341]

Very interesting carb design. It eliminates the need for a float and needle. It also eliminates the fuel pickup and return lines to the fuel tank.

[@lordjaashin]

except you have to prime it every time you want to start your engine

[@stankorecek8858]

Best video ever. Realy good explaned. Thanks.

[@pietrosenerchia1786]

You are so fantastic, that you make the understanding of the carburetor so easy,even for the first timers, thank you so much TRS...

[@brianjohnson217]

Thank you very much for an interesting and precise explanation regarding the Brigss and Stratton carburetor. I've worked on these types of machines for many years but never really got to grips with exactly how the system of the carb works . Now thanks to your excellent video I'm much wiser

[@joshuaboulee8190]

What an amazing and thorough explanation! Thank you very much! I'm going to take my carb off for the third time now, this time to replace the diaphragm! After watching this, I'd bet anything the diaphragm is my issue.

[@TheRepairSpecialist]

Thank you for your nice feedback. I really appreciate it. Craig

[@charlesauld8494]

I've been using my mower with the B&S Classic engine for 25 years or more. It has never given a problem, and has as always started first time. Last week, it started hunting, so I took the tank and carb off. Couldn't see anything wrong, so blew it all through with compressed air, put it back together, and it started first time, and ran perfectly. It has never had a new diaphragm in all these years!!

[@TheRepairSpecialist]

It's impressive that your B&S Classic engine has served you well for 25 years! Hunting, or surging, can occur for a few reasons, and it sounds like you've already done some good troubleshooting by cleaning the tank and carburetor. Here are a few things to consider: Diaphragm Replacement: Although the engine has been running well for many years, the diaphragm in the carburetor can wear out over time, especially after such an extended period. Even though it ran perfectly after your cleaning, replacing the diaphragm might be a good preventive measure to ensure continued smooth operation. A new diaphragm can help maintain consistent fuel flow and prevent future hunting. Fuel Quality: Make sure you're using fresh, clean fuel. Old or contaminated fuel can cause performance issues. If your mower has been sitting for a while, draining the old fuel and replacing it with fresh fuel might help. Air Filter: Check and clean or replace the air filter. A clogged air filter can restrict airflow to the engine, causing it to hunt. Spark Plug: Inspect the spark plug for wear or fouling. A worn or dirty spark plug can affect engine performance. Replacing the spark plug is a simple and inexpensive maintenance step that can improve running conditions. Gaskets and Seals: Over time, gaskets and seals can deteriorate. Inspect these components for any signs of wear or leaks and replace them if necessary. Governor Linkage: Check the governor linkage and springs to ensure they are clean and functioning correctly. The governor system helps regulate the engine speed, and any issues here can cause hunting. Given the longevity and reliability of your mower, it's likely that addressing one or more of these areas will keep it running smoothly for many more years. Even though it ran perfectly after your initial cleaning, considering the age of the components, a little extra preventive maintenance can go a long way. If the issue persists or you want to ensure everything is in optimal condition, consulting a professional for a thorough inspection might be a good idea. Your B&S Classic engine has served you well, and with a bit of care, it should continue to do so. Happy mowing! Craig

[@charlesauld8494]

@@TheRepairSpecialist Thank you for your reply to my comment. Everything you say is absolutely correct. I will quite possibly replace the diaphragm in the near future, because it must be getting quite weak by now!! As a retired Chief Marine Engineer, I am quite attuned to strange noises, or vibrations, but, as long as it continues to start and run perfectly, other than general maintenance and oil changes, I'm a "if it ain't broke, don't fix it" person!! Thank you for your tips and advice, it all helps, and I don't pretend that I know everything!!

[@gokalsingh9513]

Mind blowing. You are a good teacher. Thank you very much.

[@TheRepairSpecialist]

You are most welcome. Thank you. Craig

[@jadymulqueeney]

Thanks, one of the best explanations on how carburettors work, and 4 stroke engines in general.

[@TheMacaulyr]

Amazing video, helped me get the mower up and running sweet, all because of a partial blockage on the tank 'pump' area where it meets the diaphragm! After 3 weeks troubleshooting, the video saved the mower! Many thanks!

[@TheRepairSpecialist]

Thank you so much for your nice feedback and for letting me know it helped. I'm really pleased. Craig

[@chrisbutler6673]

Absolutely brilliant tutorial, delivered in a calm, non-accentuated perfect diction voice. Now I'm going to recover my lawnmower from from the recycling centre if I can.

[@TheRepairSpecialist]

Thanks so much for your awesome comment, good luck with your mower :D -Craig

[@leighporter8417]

Thank you for the effort in preparing the animation. It's very clear. The importance of the primer bulb is an eye-opener and explains the starting problem and rough running of my engine. It's really clever how the whole thing works now I can understand it! Thank you. (From Australia)

[@darrylcaputo747]

Excellent. Now I’m finally beginning to understand how small engines work. Thank you.

[@BoffinGrusky]

Excellent work!! Thank you for taking the time to put this all together!! Outstanding explanation!

[@AlejandroPerezCosio]

Great explanation, I have this carburetor and based on my spark plug inspection, my lawn mower is running lean, will start replacing the diaphragm + gasket.

[@Ricky-mouser]

All the mowers I've worked on start with the governor holding the throttle plate wide open and only until the set point is reached does the throttle plate close. Excellent presentation both in graphics and speech, well done from the USA

[@amimoses1391]

Enjoyed the thorough explanation. Wonderfully animated! Thank you.

[@ricochet5344]

Fantastic video, thank you for explaining all of this. My lawn mower has been having issues after not being used for over a year. I tried replacing the diaphragm and gasket, and cleaning the carb and tank but it still doesn't start. Having an understanding of how the carburettor works is invaluable in trying to find what the issue may be. Thank you for your videos and sharing your experience.

[@williamharshman9572]

Most people will see this video AFTER it's not working properly and NOT B 4. Thank you for your knowledgeable video

[@christianpetersen1782]

Very well done. Thanks so much for taking so much time in preparing and explaining this so thoroughly. Now we know what to clean if a change of diaphragm, seal and primer bulb doesn’t do the trick. 👏👏

[@davefenton1]

What a great, well-presented explanation of how the diaphragm works. I found this very useful and informative. Thanks.

[@jordomayor5224]

The best explained and animated I have ever seen. Finally a English-Northerner has done what many others have tried but not quite succeeded! Well done and taa a milliion for sharing this simple but most effecrive film with all us 'hobby mechanics', guess we'll be able to gain loads of 'brownie points' with our wives back home waiting for the 'damned' lawn to finally get mowen. Cheers and please keep these explanitary films coming as there better than having a million Haynes manuals clogging the shelves.

[@ClintsTractor]

This is a very well done technical video. Albeit a little long, but I can appreciate the extreme detail. This visualizes what I already know about the Sprint carburetors. I like finding additional informative videos for my techs to watch on top of their B&S Power Portal training.

[@jimbluma2558]

An excellent explanation of the operation of the very common Briggs Pulsajet carburetor

[@TheRepairSpecialist]

Thank you. I really appreciate it. Craig

[@ginaluttrell4738]

This puts everything into perspective Great vid For people who thinks this is too long to watch think again I highly recommend this vid Thank u

[@TheRepairSpecialist]

Thank you so much for your nice feedback. It's comments like yours that motivate me to continue making these videos. Craig 😀👍

[@hamlet2554]

A marvelous explanation Craig and a new subscriber. Now, if I can only get the little buggar to stop leaking fuel around the carburetor, even after a new gasket and diaphragm and a thorough cleaning. Time to pull it apart once more and double check every little hole for blockages etc. Well done mate. Such enormous attention to detail and explanation!

[@Raj-nh3fc]

My mower with this B and S motor is 25 years old and still running. The first time the carb diaphragm was changed was when it was 10 years old. That second carb diaphragm is still going strong. The primer bulb was changed after 24 years. This is one tough engine.

[@gerardsagliocca6292]

I had a difficult time understanding the first 20 minutes. It got little better when he started showing the side view.

[@brettoconnor1170]

Beaut, I changed the bulb, the gasket and the diaphragm and the mower runs lovely thanks.

[@Rein_Ciarfella]

Thanks for this one, Craig! I've watched plenty of your other carb videos but I think this is the best one I've seen in terms of ease of understanding. Yes, you did repeat yourself too much, but if in the end one manages to stick to it and watch the entire video, it's well worth the time! I'm so happy to finally understand exactly what's going on in these carbs.

[@TheRepairSpecialist]

You're very welcome! I'm thrilled to hear that you found this carburetor video helpful and easy to follow. I appreciate your feedback, and I understand that sometimes repetition can be a bit much, but my goal is to ensure that everyone watching can grasp the concepts clearly. Carburetors can indeed be a complex topic, and I'm delighted that this video has helped demystify the inner workings of carburetors for you. It's always great to know that my efforts are making a positive impact and helping viewers like you gain a better understanding of these important components. If you have any more questions or if there are other topics you'd like me to cover in future videos, please feel free to let me know. Your feedback is invaluable in shaping the content I create, and I'm here to help you with any further insights or information you might need. Thanks again for your kind words and for tuning in! Thanks Craig

[@dubblyewjay1133]

Best audio visual draw-er.. lol.. I've ever seen. Good job!

[@hanson-david]

Excellent video. I have the same carburetor in my mower and it was not running smoothly the last time I started it. I have already ordered the diaphragm and after watching this video I know exactly what each part is responsible for. Thanks and keep up the good work.

[@TheRepairSpecialist]

Thank you, i really appreciate your positive feedback

[@ajitashenoy2018]

Great animation to show how the carborator works and the fuel flow takes place. Excellent video.

[@TheRepairSpecialist]

Thank you very much!

[@grahamlee8704]

How can you not like this! Brilliant.

[@TheRepairSpecialist]

Thank you so much. Craig

[@hentieoberholster4638]

Give this man a bells for this explanation 👍

[@samclarke393]

Brilliant explanation, wish I had found it before embarking on fixing my carb.........watch out, the spring sometimes comes off when dismantling and is easily mislayed. Thanks

[@marcinbujok7388]

Wow! This explanation is magnificent! Thank you for all the effort putting it altogether is such precise way.

[@brianeaton9741]

This is by far the most detailed explanation of . How this type of carburetor works . My hats off to you. Great job. THANK YOU ! I hope to enjoy more from you in the future. Excellent work. Two thumbs up. More if i had them.

[@gregtarasinski5516]

Great video, I studied this carby n worked out exactly how it works, the only thing is....carby butterfly is open fully before starting because the vane governor has no air pressure against it to help it close, the governor spring pulls it wide open, And when primer is pushed this actually squirts the fuel in past the open butterfly. Very simple but effective carby Cheers

[@eananstrain6817]

Wow, really great description. Thanks for going to all the effort, looks like you had to draw all those diagrams etc, great stuff, thanks! These units really are very compact and clever, genius design

[@daviddedick14]

Always wondered how these ‘mysterious’ carbs worked. Brilliant, clear and detailed explanation. Thanks very much!

[@chris999999999999]

As someone who's job it is to train people, your videos are fantastic!

[@rodrichards6148]

Briggs and Stratton. Love their engines. The occasional blop blop blop (unleaded fuel?) and they just keep chugging along. Thanks for the video. I always pump 4 times. Never fails to start first pull.

[@Aerogrow]

heh; worked on for years during go-cart racing years; always wondered how the diaphragm and pump worked. Just knew when we ran alcohol; changing that diaphragm out became a bi-weekly thing (dries out and cracks). Nice vid; very clear.

[@waynetetley584]

Really helpful. Thank you. And agreed it's a neat design. This info saved me replacing a carb today. Dirt in the main jet removed using carb cleaner. Mower runs fine now. Over the moon 😊👍

[@kevinchissel1767]

havincg just bought a secondhand rotovator with running problems, engine starts ok if you put a bit fuel in the air intake of carb but wont continue to run, this video has gave me a great insight into how the carb should operate, thanks for sharing this it is fantastic, i am off to buy new gasket and diaphragm set. the engine i have is an older model as its an alloy carb with no priming bulb but i am sure it will be the same principle-

[@luilui03able]

wow this is an excellent tutorial,cus so far every video I watched shows how to fix it ,which is nice,but this shows how it works very detailing. makes easy to fix carbs, nice job

[@markhaywood5920]

That was fantastic! Thanks for your time for making a detailed explanation and sharing, especially since i just thought it was a question on force and patience. Great job and thanks again.👏

[@TheRepairSpecialist]

You're very welcome! Craig

[@a.j.r.cushman3963]

Thank you so very much. You even taught me, through extrapolation, how my jet pump works.

[@cbobcbob100]

this is the greatest video dealing with operation of b/s carb have every seen.....thanks so much

[@wypapitjiity]

When I was an apprentice,on day release at North Trafford college,some 35 years ago,you'd have been the greatest!

[@movaughn20]

You definitely put the "TT" in Carburetor! 👍 Explanation is excellent. 👏

[@magallsys]

Thank you for this video and clear explanation for 35E classic carburetor. I bought this lawn mower in Feb. 2005 and have not had any problems until yesterday. The engine keeps cutting off after about two minutes and I thing the carburetor needs an overhaul.

[@AdeSwash]

Thank you for this clear explanation. I have a vision of Mr Briggs sitting at his drafting table scratching his head

[@johncunningham4820]

One of the Simplest and Reliable Analog fuel metering devices ever made . Really Clever design and manufacture . Beautifully SIMPLE . Beautifully presented explanation , for those that already have some idea how Internal Combustion works . I could go into business right now , fixing these . There is a Separate system that needs explaining , as well . The Governor . Probably centrifugal on these Engines . But perhaps not . Briggs and Stratton's are a Petrol Engine that behaves like DIESEL . Rev-limited . Dig in as needed . I like your Channel . Subscribed . I , myself , am Former Navy Engineering Sailor and a Motorcyclist . Rat-rodded a couple . Haha .

[@parochial2356]

Superb animation. Thank you for the effort. I now have an excellent understanding of these carburetors.

[@mikeflight9]

Brilliant video. I have a Briggs and Stratton with that carb and now I know how it works. Thank you for sharing.👍👍👍

[@adnacraigo6590]

I had thought of these as similar to 2 stroke type but never heard anyone say that. Thanks for the well thought out video.

[@franklyncumberbatch9494]

Franklyn c. This is amazing it's two much. Knowledge at one time for me to re member excellent that 's what I call a genious

[@vikramodedra4351]

So Far best explanation of this genius technique used to create fuel pump using just spring and diaphragm 👍

[@TheRepairSpecialist]

Glad it was helpful!

[@gpizanok]

I was searching high and low on an explanation of the primer circuit on these carbs. This is a brilliant tutorial on that! Thanks for the effort you put into this.

[@davidlau1666]

Thanks

[@WillGnass-hr1ru]

I’ve never understood how those pump fuel because I never could find a passage that goes to the crankcase like on a 2 stroke . Thanks for the excellent overview, I get it now .

[@foreverwood1963]

No one explains this better than the Repair Specialist

[@TheRepairSpecialist]

That's really kind of you to mention. Craig

[@foreverwood1963]

@@TheRepairSpecialist What's even better is I believe it's true.

[@glynnraynor6119]

Excellent piece of work, very well done

[@Eagle031265]

Awesome explanation, thanks for your time to prepare this. Greetings from Costa Rica

[@sdhaliwal22]

best explanation ever , and answers of common questions come in mind during learning.

[@TheRepairSpecialist]

Thank you for your awesome feedback. I really appreciate it. Craig 👍

[@CatLegoDiver]

suberb video. So well constructed and explained. I took my b & s carburetor apart before I watched this video because my mower wouldn't start. After putting it back together I was bummed when it still wouldn't work. Now that I understand what I'm looking for, I'll buy the repair kit first before I take it apart again. I did notice that it was missing the mesh filter around the injector so that could be an issue. I also will have to ensure that the gasket and diaphragm are the right way round. Thank you for this! I'll let you know how I make out. :-)

[@campbellmorrison8540]

Very clever design and equally brilliant explanation thank you

[@TheRepairSpecialist]

You're very welcome! Thank you so much 👍👍👍👍

[@ronnieron88]

Great video very well explained, I only had a rough idea how it worked but now I understand a lot better, thank you

[@michaelg7713]

Thank you for a very informative video on a amazing and simple piece of machinery

[@Mk-oy9ns]

What a fantastic resource your channel is,Thankyou.

[@Portergetmybag]

I am so very grateful for this video after spending hours figuring everything out through trial and error. The time and effort you spent to help me is really appreciated. It took me 20 something videos to get to what I needed. I hope everyone remembers to hit the like button because the algorithm must lower this because it’s “too long”

[@TheRepairSpecialist]

Thank you so much for your feedback, you are right about the length but I did have to make it quite long to get all the information in :) - Craig