CHAINSAW CARBURETOR LEAKING GAS/FLOODING: Why Carburetor Overflow? (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 😊👍

[@cookiemonster7180]

25 years in grounds, starting with little old lady's yards, up to the manager of grounds at large university in southern USA servicing at PGMA levels 1 & 2 in commons of main and 4 satellite campuses, in addition to sports venues of 5 nationally ranked collegiate level athletic programs, and have secretly been woefully lacking in skill when dealing with two stroke engines having carb trouble. With your being willing to share your knowledge, I will now most certainly be able to master this shortfall in the presence of my staff. God bless you sir, and many thanks!

[@paulcombes3782]

Excellent video , and thank you for your extensive diagrams helping others see some of the common causes of a "wet" combustion chamber . You are a great educator .

[@Vfh........y]

Easily the best video I've ever seen on two stroke carburetors on operation and performance. Good show. SIR

[@haeke69]

Best explanation ive seen . Understanding the theory really is the difference between becoming an expert and just being a user. Now I know how to diagnose and determine what is going on when problems arise . Thankyou sir. Look forward following more tutorials

[@joebuttas26]

Wow, this is why I love youtube. Thank you for the time and effort you've put in to this for us.

[@tomharries847]

absolutely amazing video I cannot thank you enough. I work in a garden machinery workshop and these small things were not taught when I was learning. I can fix 98% of machines but recently had a kawasaki hedgetrimmer which was flooding excessively. I tried a new set of fuel lines as the old ones were perished, a new fuel filter, a carb overhaul kit and it's still flooding. you can pull it over and leave it and the fuel will still come out of the air filter housing and into the cylinder. after watching this I am definitely going to look at the metering diaphragm and needle assembly as it is most likely this. again thank you for your help and I will continue to watch your videos as they are so well set out and uncomplicated.

[@untildenmyfren5919]

Best & most detailed Carb explanation video thus far!

[@alryley2]

Amazing video. I really appreciate the time and attention to detail you put into this

[@buurton1]

Best 2 stroke lesson on youtube.

[@anitacox7597]

Thakyou for your videos they really help me better understand. You are never too old to learn.

[@Rick-td7qh]

After many frustrating failed attempts to get my 2 stroke line trimmer working, these valuable and brilliantly presented insights got me over the line. Believing that I understood 4 stroke engines pretty well, I wrongly imagined that a two stroke engine would be a pushover. These great videos have shown me how a failure in one part can easily look like a fault in the other. I'm still not sure of the root cause in my case, best guess it got chronically flooded due to old fuel. I went straight to the ignition, checked the magneto, replaced the spark plug with one that looked right, but the electrodes got crushed because they protruded below the piston crown. Realized this, returned to the shop, was then advised it was probably the carby, so bought a carby kit which again looked right. Still no start, not a pop. Other you-tube videos advised the most likely remaining explanation was compression failure: the ring was quite loose with 0.5mm gap, so I found a replacement ring and fitted it (still some gap ~0.3mm, but that was all I could do). Still nothing, not a spark. Almost gave up, but for some reason decided to again watch the excellent explanations on this channel. Finally, thanks to this particular video, I went back into the carby and realized, just as he says at the 8:00 minute mark, the needle valve lever was set too high, causing continued flooding. Went back to the old lever, suddenly everything is great! Starts first time, every time, all the new parts have paid off, but I think it was all down to flooding and my failure to realize it. To their credit, the place that sold me the wrong plug and dud carby kit did give me some good advice about carby diagnostics: take it off and see if it can fire without it. If its flooded, I learned, it can run for quite a while from the fuel that's pooled in the crank case. Kudos above all to you, Repair Specialist!

[@jakesharman7037]

Mechanic here. Great video, very informative and a good refresher. Thanks for your hard work 👍

[@TheRepairSpecialist]

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

[@roymg]

I've fought with these little carburetors many times talking them apart cleaning and installing kits but I never dreamed there was so much detail to be had with these things until now. Thanks for the lesion.

[@martinfinster9899]

Fantastic editing and visual demonstrations. I've been repairing machines of all kinds since a small lad and I learned something. I just went psychotic on a small trimmer (threw it across the lawn) that's flooding and came inside to check youtube and here you are settling me down. Well done!

[@andresdominguez7021]

Most of those who teach on KZbin are very boastful, you are very didactic thank you very much.

[@TheRepairSpecialist]

That is a very nice comment. Thank you.👍👍👍

[@souldrinker7008]

No doubt you recognise my name by now; so prepare for more fanboying. Fantastic video once again, I don't know what else to say other than please keep making videos, you're such a fantastic teacher and an invaluable recourse to students of Mechanical Engineering like myself.

[@TheRepairSpecialist]

Excellent, thank you!

[@brotherkith]

TheRepairSpecialist

[@matasgruzdys1096]

Man I thought I will have to sell my bike

[@puzoniasty1973]

That is perfect explanation what could be possible reason for 2 stroke engine malfunction. I spent a lot of time watching tons of videos about the problem and none of them was so clear and taking to the point as this is. Now I know what exactly I should pay attention to repairing the engine. Thank you Craig!

[@IntoEverything]

I really appreciate how well you explain processes and the minutia. I finish your videos with a solid understanding of function and the mechanics involved. You provide a top-notch, proper education. Cheers.

[@TheRepairSpecialist]

Thank you so much for your kind feedback. I really do appreciate it. Craig 👍👍👍

[@paragyver]

Thank you for taking the time to make this video and explaining so it clearly. I certainly learned alot . Now to go and diagnose my 2 stroke and hope I get it to start.

[@brainfeed6604]

Hi again like the comment below your video`s really inspire me to get all my none running brushcutters and strimmers going again,I was always a struggling student at school and always told to just go to sleep or just look at the book if you don`t understand.I never learnt much at school only read and write and low level manths,But pretty good at maths now in my head never used a calculator.I found out later in life I had a reasoning problem,This meant the way I read or got told how to work out things needed to be explained in a slightly different way or break things down more than it would need to.Any ways I have no issues in the way you come across explaining I understand perfectly,You understand when teaching people that they literally don`t have a clue to begin with` this way you can learn the ones who really don`t have a clue`and this is how teachers should be teaching pupils,I truly believe to learn someone they have to take things back to there basics and never assume people have a general understanding to start with as this will leave many pupils behind scratching there heads.I don`t know your back ground but if you were a teacher at college then you would not have many scratching there heads.thank you again.

[@billjackson4469]

Great have been struggling for ages on a carb issue, this really covers the possible issues I am having. Thanks

[@TheRepairSpecialist]

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

[@extra330sc]

Thanks very much for producing these very useful videos. I use Walbro and other similar carbs in my R/C airplanes. I have a 30cc engine that has been been out of service for several years. It now refuses to run. After watching your vids, I’m fairly confident I’ll find problems with diaphragms in both the fuel pump and metering systems. Carb repair kit is on the way. Thanks again.

[@bryanwhite3013]

Thank you ever so much. My "new" secondhand Stihl KM85R arrived not working. Following your instruction I was able to get it working. My very first engine that I've successfully fixed. :)

[@Akbar_Friendly_in_Cherno]

Best explanation I've ever seen. For anything. Ever.

[@aegairsoft11]

Thank you very much! This is just what I was looking for, a well spoken and informative lesson on troubleshooting engines, consumable by newbies like me. I will definitely be watching your other videos.

[@DueceBigelow]

best small engine carb video series I've found! Brilliant and thank you.

[@petebunce9505]

By far way and above any of the dozens I've watched trying to resolve this issue.

[@rankinspeed2805]

Excellent video the best explanation I have ever seen on a motor. Hats off to you.

[@jassibrar8418]

Thank you for this information, I understand this subject much better. Love how you explained everything, thank you!!!

[@Nonplused]

I watched this video a couple of days ago because my 2 stroke outboard has for years been nothing but problems. Rough idle and stalls, check. Hard starting, check. Wet spark plugs, check. Smoky, check. Adjusting idle screws made little difference. Fuel pump working. However, I never did think to check the oil pump, I didn't know the oil mixture could flood the engine until watching this video. So I search up a service manual to see how it is supposed to be set, and wouldn't you know the linkage was connected on the wrong side! Way too much oil at idle and turning backwards with throttle! I had some major work done some years ago and apparently someone screwed that up when they put the carburetors back on. You can just clip it on and off on either side, but only the way shown in the manual can lead to being able to adjust so that both the idle and WOT lines match up with the set mark. So thanks! I haven't got it in the water yet to try it out, but it is already idling much better and making less smoke. Still some smoke though, enough I'd say to indicate it is still getting oil. But on the other hand I don't know how much excess oil is in the crankcase, so I think I have to get it out for a good run and see what happens.

[@ckpankratz]

Excellent, thorough video with outstanding explanations. Thank you.

[@robindeakin9078]

I thought I would just put this out there! On the subject of old fuel, I have a small boat and for my own safety need the outboards to start frist time every time,, I keep my carbs, filters and containers clean and also filter fuel every time I transfer it, lately I have bought fuel and found it to be no good I live in south of england and I think its because there is not so much fuel being used, I now have to put a small amount in my container, smell it, to check if it fresh then decide if to buy a full container or the walk away I worked with small 2 stokes for over 50 years and this is a new issue, welcome to the 21 century UK!

[@riverraisin1]

I'm having a problem with a two stroke leaf blower suddenly flooding and not starting. I disassembled the carb (but not completely) and cleaned the diaphragm, choke, bulb, etc. with carb cleaner but still have the same issue. By watching your video I now see how the fuel flows past the needle valve. I will remove the needle and lever assembly and check that out next. Outstanding video!

[@TheRepairSpecialist]

Thank you so much for your positive feedback! I'm really glad to hear that you found the video helpful in diagnosing your two-stroke leaf blower issue. It sounds like you're taking some great steps in troubleshooting the problem. Cleaning the carburetor components and inspecting the needle valve assembly is a good approach to address fuel-related issues. Sometimes, even a small blockage or debris in the needle valve can cause flooding and starting problems. If you encounter any challenges during your repair process or have any more questions, feel free to reach out. I'm here to help, and there are often many knowledgeable folks in the KZbin community who can offer guidance as well. Best of luck with your leaf blower repair, and I hope you get it up and running smoothly soon! Thanks for being a part of our channel! Craig

[@riverraisin1]

@TheRepairSpecialist Thanks for you reply, Craig. I did completely tear the carb down and cleaned the needle valve, even though it looked real good. Because I didn't have gasket sealer on hand, I used a thin film of Vaseline on the cardboard gasket between the cylinder head and carb, thinking there could be air leakage at the joint. I opened up the crankcase and inspected it out of curiosity, and also removed the muffler and blew it out with compressed air in case it had a blockage (plus it was saturated in fuel). Reassembled and pulled the starter cord. It fired and I got it slowly running at half choke. It blew smoke for a good minute or so until the engine heated up. Then it ran good. Shut it down after 15 minutes of use and let it cool down a while. Fired right up when I restarted it so I shut it down thinking it was fixed. Today I tried starting it with no luck. Spark plug wet, no fire. Starting fluid not helping Blew the cylinder out to dry it and pulled the starter about 25 times straight at half throttle. It fired up hesitantly and was hard to keep running. Again, blowing smoke out the exhaust until the motor got sufficiently hot. Even though I'm always careful, I'm now wondering if it's a fuel to oil mix ratio problem? Gas is fresh.

[@MrJohnnydublin]

Havin problem with a small zuma carb.im watching theses videos over and over.I will fix it eventually.Thanks thanks 🙏 for the videos man !!!

[@kookooglue]

Amazing video, never had anyone explain the possibilities that cause flooding so well, nor how the carburettor works.

[@johnhutsenpillerjr1785]

great video Sir. fill the fuel can/gas can plumb full, put the can in the sunlight, let it warm up, then seal the can. put it in the shade and when it cools it'll create a vacuum, prevents fuel contamination and reduces the aging process. all the best Sir.

[@arunmonc.t5214]

You are a good teacher also... Very good lesson that I learned... Love it...

[@dobermangang6216]

Awesome videos, I have two weed eaters that I have fixed now with the help of your carb videos. They've never ran so good

[@LLuE88]

finding this video, or better explanations elsewhere, would have saved me many hours/days of looking for answers to my weedeaters carb problems. thank you so much. even though this seems rather simplistic, video does a great job explaining the correct functions inside of carburetor. Your videos on this subject should be a must for educating those interested in solving carb issues. I believe there are at least three of them. regards

[@WalkOverHotCoal]

You obviously have put in a lot time and efforts into your tutotials. I like them very much. The what, why and how are covered in great details. Perfect. Thank you very much.

[@flamingo2005]

Beautifully done - thank you so much for this informative lecture!

[@douglas9607]

Good presentation. I always get a new perspective with a fresh explaination on a subject. Thank you for the video.

[@douglas9607]

and Greetings from Maryland US.

[@TheRepairSpecialist]

Thank you very much. I love the US. One of my favorite places on earth.

[@TheRepairSpecialist]

Thank you for your nice feedback. I really appreciate it, and thank you for being a valued subscriber for the last year. Craig👍👍

[@JArtMiller]

Another very well presentation using very organized thoughts and visual aids... Great job.

[@arthurfricchione8119]

Excellent video. Thanks for all the useful information. Now to try and implement all the possibilities and resolve the issues. 👍👍👍

[@fullyarns]

I have a machine that floods itself when not running and the fuel tank lid is screwed on. It will literally dump an entire tank of fuel onto the floor in a day. Best I can tell is the needle spring is too weak and can’t handle any excess pressure in the fuel tank side. Cheers for your video’s, they gave definitely furthered my understanding of two stroke carbs

[@TheRepairSpecialist]

Hi. Thank you for your feedback. I really appreciate it. Yes. I agree that it does, initially anyway, sound like a needle valve issue. Yes it could be the spring. It could also be a damaged, or worn, seat or needle tip. If the needle tip is metal and does not look worn then it could be the seat within the carb. If the needle does have a rubber tip then you might see a ring of wear on it. I've had issues in the passed like this though, and both the needle and seat looked ok, but it wasn't until i changed them that it cured it. I suppose there can be wear and damage that is sometimes not so detectable with the naked eye. Thanks again Craig

[@redderome6381]

Great video, extremely clear and well explained. I will definitely be checking those points.

[@TheRepairSpecialist]

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

[@evangeloskatsogridakis166]

Thank you so much, extremely clear description and explanation, a lot of talent and a lot of work from your part.

[@ericanderson1846]

Such an excellent course! Thanks very much for all of these videos!

[@FlyingJJD]

Wow, excellent video. Great explanation, and your illustrations were very well done. Hats off to you sir!

[@drewsteffey7687]

That was terrific, just very informative and well conveyed with the visual aidand appropriate dialogue...so just good job man that was exactly what I needed to help diagnose my crazy flooding in my workhorse Husqvarna that had me scratching my head a little bit this morning when I did the usual go to remedies with the break down and clean up. Thank you again good sir

[@TheRepairSpecialist]

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

[@stevebarker1974]

Extremely knowledgeable and informative great vid easily explained 👍👍

[@arthurhamuth]

Thank you! Thank you! Thank you! Thank you! Thank you! Thank you! Thank you! Thank you!...and so on...

[@syedrazi2545]

Thank you so much for explanation you are a great technician and teacher. In my case I bought second hand weed eater when I open the carburetor I found the pin upset down and could not figure out why it is not starting I clean the carburetor and check the spark every is looks good and after explaining I found the problem I have to open the carburetor and put the pin properly I think it should start. Thanks

[@TheRepairSpecialist]

All Episodes -for 2-Stroke Carburetors Here. Thanks. Craig: kzbin.info/aero/PLrlXp3PlwgRI5OLvm3P91LJr1CYnO5TRD

[@RockCrushing777]

Man best video on engined..great illustrations too thanks ...please do more you cant go wrong.

[@TheRepairSpecialist]

Fantastic feedback. Thanks so much

[@razdog9977]

You are my kind of teacher! So well explained. I found answers to questions i had not yet asked. I would shake you hand if I could, even with covid19!!!!!

[@Nouvelnoula]

Best teacher ever I love men

[@erikbaeyens2043]

Hi, great video, fine explanation, love your work. But probably you could mention (or make another excellent video) how to avoid a lot of problems with degrading fuel by using Alkylate fuel instead. Alkylate fuel has no degrading over time, has no ethanol added, has the right oil percentage mixture, doesn't build up sludge in your machine, better starting, longer lifetime of the motor and best of all: it's much safer for your own health by not having benzene or aromatic hydrocarbons in it. It is also highly recommended by a lot of machine manufacturers. Downside is that this fuel is pricier, but I personally think that it pays for itself in a number of ways. I use this type of Alkylate fuel in all my small machines for about 20 years and I am very satisfied about it.

[@TheRepairSpecialist]

Erik Baeyens, ok, thanks for your feedback, I really appreciate it.

[@deweyself4508]

thanks for the schooling,that saves a lot of trouble..

[@LLuE88]

** the issue of the needle lever position**, bending if required, is most often not addressed in rebuilding or adjusting parts of a 2 cycle carburetor, thank you, regards

[@LeeRiverGuy]

The other factor for gas at the pump is the grade of fuel ,here in North America we have bronze silver and premium. Premium being the best to use. Now the thing you have to realize is this, if you want premium gas in your jug when you get to the pump you don't know what grade the previous customer used. So if the person used bronze there will be a couple of litres of that in the hose line, therefore you are not getting 100% premium. Best thing to do is put 2 - 3 liters of the gas in your vehicle then put the 100% premium in your jug.

[@peterford9369]

Hi, I totally understand your explanation of the carb operation. My issue is, my chainsaw starts, sometimes easy sometimes takes more pulls. New carburetor, trying to adjust, runs well, but when returning to idle sometimes dies,,, but then doesn't start right back.. My problem is the inconsistency in starting and returning to idle from high speed. Have several engined tools so not totally a novice, but when these tricky ones come up it's very frustrating. Also, I use canned fuel when first getting an engine going, so fuel is good. Seems carb issue but always looking for advice. Thanks for your very helpful videos.

[@benole517]

It´s a really good Explanation. THANK YOU

[@wiley0714]

your videos and illustrations are totally awesome and I thank you again for taking the time

[@alfredgarcia6608]

Thank you. So much great information 👏.

[@johnncube8201]

Informative indeed, thank you.

[@servipasto]

Excellent detailed explanation!!!! thank you soo much, it really helped me understand my problem and the way the 2 stroke carb works. great video!!!! Atb.Jenaro from Chile.

[@alexusvillareal]

Great Video !!! Very Very Well Explain , Just felt when back in School. ..

[@thomasgronek6469]

Thank you for another FANTASTIC video. At about 15 minutes, when we blow air into the fuel line, won't the air pressure open the needle valve, and cause air to push through? Thanks again for another fantastic video, and taking the time to answer my question.

[@jacquescote2585]

Great work again! Craig

[@TheRepairSpecialist]

Thank you. I really appreciate it. Craig 👍👍👍

[@bjack8645]

Jolly good mate!

[@TheRepairSpecialist]

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

[@toptunesa1345]

Yo you just solved my problem my engine is now screamingly working purrring like a cat now after it starts THANK YOU I’ve just got into engines for bike projects go karts etc I don’t even have a welder but one day I will afford one u can use one as I learnt in rover BMW 10 or so years ago so I thank you and if u have any more advice on diy speed projects let me know YHANKYOU SO MUCH!!!!!!

[@TheRepairSpecialist]

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

[@GeoffreyGraham2]

Thanks for this my Whipper Snipper starts but chokes out in 5 to 10 second! I replaced the plug and fuel. I have not checked the fiter yet.

[@ludeboukema4111]

i love your channel thank you

[@Crest591]

Great Explanation.

[@TheRepairSpecialist]

Thank you

[@steveforrester2217]

Great video. Thanks.

[@matthewrichardhassall9798]

Good very informative

[@eroshtik6997]

great video

[@TheRepairSpecialist]

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

[@gregjohn5261]

Thank you so much for this video it was really helpfull

[@diarmuidoc9427]

Great video!

[@brainfeed6604]

Craig,listening to your theory on air in the fuel can maybe you should invent a depressuring method to extract air out of the petrol can,If I am correct doesn't the car depressurise the fuel in the tank when turning the key be for the engine starts.If you do invent this then remember it would more likely have to be a tough flexible plastic,this would prevent tipping the fuel into a smaller can every time you use the fuel to reduce the air.Just remember who gave you the idea lol.

[@user-lc7xb5ch5t]

Great content .

[@cousinfuzzy4544]

Damn this guy is good !!!!

[@GmGarlo]

Awesome explanation!! do you have any videos on backfiring in engines and can it cause damage to your engine?

[@RoryTrackrod]

Another fine video you've got me into. ..

[@middlejamaica5313]

very great info helps me alot

[@_.R.F.X.L._]

Hey if i port the intake, and put a biger main jet and a atomizor with more holes for more air can i gain little power?

[@AndysDogHouse]

This is a great video. You explain it just right. Now I will have to watch it again because I am new to small engine. I have an older Homelite chainsaw and it floods if I don't get it started within 3 or 4 pulls. The gas ends up coming out the muffler. I don't know if this is something I can resolve with an adjustment, or do I have to put id a carburetor kit. Do you have a rebuild video posted? I hope I can find one that will teach me. Thanks you and keep up the great work. You sure know how to explain things Andy

[@johnmolina9694]

The best of all others.

[@mowtoegee7049]

Thanks for this very informative video. The visuals make it so much easier to understand. I've got a 2 stroke garden machine. Cold starts perfectly fine but very difficult to warm start. If I unscrew the spark plug and crank it without the plug in - then put the plug back in, it eventually starts again... Trying to figure out the issue. Air filter is good and spark plug new. Thinking H/L adjustment screws Cheers

[@nidaulhaq1601]

Hi there,i drive a two-stroke motorbike.... this video has been a great help...No doubt. But still i would ask question that is,most of the time my bike bogs down in a running condition. Other than that when i run it for a kilometer of 30-40 after shutting down the engine it doesn't want to start.....i took a look at my spark plug its peach black in color and dry. Along with that most of the time before i used to face overflow and no start condition. Would you please be kind to enlighten me about the trouble i've being facing? Although i got to know a lot from your video. Such a great explanation. I would be waiting eagerly to know feedback from you. Thanks.

[@sportster88]

Very good explanation! What effects do faulty internal check valves have on the operation of the carburetor?

[@davidsardarov252]

loved it!

[@TheRepairSpecialist]

Thank you. I really appreciate your feedback. Craig 👍

[@Crappie_Hunter_Seeker]

Excellent !

[@magicalempire]

brilliant knowledge

[@ackeheh]

My chainsaw was getting drenched with fuel and would not run. Took it a part maybe 5 times nothing was sticking out. What it really needed is new diaphram i guess. It was so stale that it was just hitting that flap that opens the needle all the time. All I did was press the flap down a tad and the saw was running like new again. I really should have rebuilt the carb but eh. :)

[@theredstormer8078]

I'm looking into building a forced induction system. How would I get the right amount of fuel into the system?could I just force the air into the normal intake and run it a bit rich?

[@kingjames4886]

I find my gas keeps for a couple years without much of an issue, by about year 3 it starts to really bog things down tho. I don't use the weedwacker a lot... so there's always some left over.

[@brainfeed6604]

Hi Craig,I had a leaking carburetor so I bought the kit,containing needle etc and diaphragms and cleaned with carb leaner then in a cleaning machine for got its name then dried it with carb cleaner again and air dried it,but it still leaked out of the edges where the gaskets were applied`when i put 10 psi to it,but the bubbles were less and slower.I tuck it apart again and realise under close inspection there were very fine scratches to the surface that would lead out to the edge. Now i new air was running along the very fine scratches and coming out under the new gasket.Could i sand the carb with wet and dry to lesson the scratches and remove them from leading out to the edges?also is there any thing I could do instead of sanding on a glass sheet with wet and dry,Like swelling the gasket first so it get compressed into the scratches or apply a film like a filler be for applying the gaskets.?any advice would be grateful please.