There's gas coming out of my muffler! Dang Chainsaws!

Once again I'm letting you guys know whats happening inside your chainsaw. The symptom is gas coming out of the muffler. The cure is to properly adjust the metering lever inside your carb. NOTE: often times the metering side of the carb is on top when you remove the astics and air filter cover. You MAY be able to re-adjust the metering lever without taking off the whole carb. Question? Comment? Keep it to yourself. Im out!

[@ZombieDaveAZ]

First time viewers and new follower please dont be shy to comment. Off topic questions are always welcome. Maybe you want to see how to install something or you have a click clack noise that has nothing to do with throttle adjustment. Ask here because someone else will or my learn something. Sometimes you see a tip or method that will apply to your DIY fix. Thanks to all the Guys and Gals that follow this channel. Zombie Dave

[@bryanwright7990]

This was insanely helpful. Much appreciated. I had never seen so much gas inside a chainsaws muffler! I had no idea why it would get so darn flooded but now it makes plenty of sense.

[@jasonsouthwick621]

Wow. Totally hit the bulls eye with that tutorial brother. I was having problems with my climbing saw. Fuel in air screen and air filter as well as coming out exhaust. I've chosen to do all my own work on my saws about two years ago. It took several hours going through KZbin videos to find this. Thanks

[@ZombieDaveAZ]

If you ever have the need for a direct answer just ask the question and I'll do my best to help you out.

[@jasonsouthwick621]

Thanks will do. I'm not shy, I was taught the dumbest question was the question not asked.👍

[@christopherholmes9513]

Working on concrete saws now as a new task after our mechanic unexpectedly retired-Thanks for the in-depth view answering a question I've been trying to work through on my own

[@LifewithJames]

Awesome teaching. I have an older craftsman saw that I bought to clear land I purchased and it fills the muffler but won’t crank. This nailed the problem instantly

[@johnjaniga2438]

Thank you Dave. It's good to know why something doesn't work and then follow it up with a repair.

[@terrymcclean4582]

Your reference back to an earlier video about the Poulan restart problem was very helpful. You have lots of good information and by pointing to it you don't have to repeat it and enable us to go find it ourselves.

[@ZombieDaveAZ]

Terry McClean the pic you sent me in email of the metering diaphragm is upside down. Was that intentional?

[@terrymcclean4582]

"upside down"? No, that wasn't intentional, it was taken immediately after I removed the cover plate. But, I've checked some exploded diagrams and some youtube videos and it doesn't look upside down to me. I'm confused.

[@terrymcclean4582]

In my mind, my pic was the same as I see at 7:40 of your "2 stroke carb clean 100%. Part 1 of 2,You can do this!"

[@ZombieDaveAZ]

Terry McClean hey buddy thanks for the comment. Its totally fine to go off topic with a question. Whoever else reads these comments may have a similar or the same problem so I say go for it. It also gives me fodder for new videos. Thanks for Subbing.

[@ZombieDaveAZ]

Terry McClean if the pic was taken just after cover removal it is on correct. Im just covering all the bases.

[@kenchasser4376]

Replaced this carb diaphragm on my Poulan Wild Thing 2375 and fixed the problem. Thanks, great video!

[@mason8997]

Thanks very much Dave. I have a Poulan Wild Thing that used to work fairly well. I've been scouring youtube to find some ideas on how I can get it back to running like it used to. I find your explanations and diagrams very helpful getting me to understand what exactly is going on with and why things may not be working the way they are supposed to. Along with watching someone do the repair it is helpful to understand "why" it needs to be done.

[@robertlehrman5832]

I’ve got a Craftsman 18” 42cc. New carb, fuel lines and filter, air filter, and spark plug. Can’t get it started. Spitting fuel from the muffler. Haven’t made any adjustments yet.

[@ZombieDaveAZ]

@@robertlehrman5832 Rob, shoot me an email if you can zombiedaveaz @gmail.com I assume you have a smart phone?

[@cranialextract]

Super helpful. Thanks, I just rebuilt my carb and probably switched the gasket and diaphragm. I'll check this aft. Thanks again.

[@luked1964]

You are an amazing teacher. I couldn’t explain this any better.

[@ZombieDaveAZ]

Thank you Luke. Very kind of you to take the time to encourage me. You're the best!

[@ZombieDaveAZ]

Thank you Luke. Very kind of you to take the time to encourage me. You're the best!

[@TheCrittercam001]

That was a great learning video buddy and with the humor thrown in for good measure made it awesome!♥

[@jayginn4980]

Dude that was the absolute best explanation ever. I consider myself to be fairly good with mechanical issues. Hell my job for 20 years is industrial maintenance and also electrician. Any way i have a chainsaw that was given to me no one could fix but i took it just to see if i could fix well if it wasnt for your video it wouldnt be running. All i can say is right on i tried every thing but your ideas worked not mine but we fixed it brother thanks man u r the shit

[@ZombieDaveAZ]

Best compliment I ever got Jay. I appreciate it very much. Stay safe 😷🍺👍

[@Jeff-nw8lt]

Great tutorial

[@krishnachandradatt1997]

Good demonstration, thank you

[@rastagrastag7784]

Thank you. Very well explained

[@Seriouslydave]

I look at my engines differently now thanks, had fuel spraying out muffler. Try some dot3 on the diaphragm then rebuild next.

[@tobyrodock7200]

I have a craftsman older craftsman chainsaw why do I have fuel coming out the top of the carburetor is this my problem I need a carb kit

[@ZombieDaveAZ]

Toby Rodock Hey Toby. Without actually seeing the saw, it actually sounds like a fuel line is compromised. Cracked, broken etc. Does the fuel become more visible after pumping the primer bulb? Through process of elimination we can get you up and running.

[@TheKing.ofPlebs]

Amazing video, thank you

[@ZombieDaveAZ]

Thank you!!

[@jeffreyfullwood6417]

Thank you 👍

[@zackmccord1957]

So helpful man you just saved me a bunch of money i wus about to go out and buy another chainsaw been working with this one for about 2 years and I was going to put a whole carburetor on there which I order a little bit ago but I cleaned this 1 up and it's still doing it but now I know why thanks

[@ZombieDaveAZ]

I really hope you get it going. Mostly just because of the feeling you get when you fix it yourself. Thanks for commenting and please stay safe and healthy. 🍻😷👍

[@h.kallensoa4581]

I have black wet residue coming out of the muffler on an old 024 av Stihl Wood Boss. And it smokes a little bit revved out.

[@ZombieDaveAZ]

You are right on the cusp of this happening. Its long drawn out but you will understand it when its over. kzbin.info/www/bejne/rX-3fIKrgNyLl6s

[@tobyrodock7200]

It’s a craftsman 358.355161 getting gas could diaphragm be causing gas spitting from top of carb and preventing starting

[@ZombieDaveAZ]

Toby Rodock yes. Think of a carb as a pump and not some intimidating complex maze. Gas should never leak,squirt,seep outside of the barrel of the carb. If it is hard to pull and you smell a ton of gas,remove the spark plug and turn the saw upside down and pull the rope. If gas comes out the spark plug hole, the metering diaphragm is stuck in the open position. The crankcase may have fuel in it too. This is usually pretty noticable because of the strong gas smell and if you put it away full of fuel the tank will mysteriously be lacking fuel. Its in the crankcase.

[@anam4582]

I dont even know what to do now 😂

[@piecetoyou8285]

Thank you for sharing your info, I have a petrol strimmer that was not starting,Once i undone the fuel tank cap the fuel came streaming out of the air filter it would not stop,and i noticed the strimmer pull cord was juddering as if the timing was of, Could this be down to a vacuum issue with the petrol tank lid not pressurising .or would you say its the diaphragm? really need an answer to this issue please,

[@ZombieDaveAZ]

Start with the easy stuff first. Gas caps let air in. Some trimmers like echo actually have a vent. My gut tells me the diaphragm is holding the lever partially down.

[@ashtoncoolley4808]

Good video, very informative, thanks a lot!

[@ZombieDaveAZ]

Thanks A. Glad you took the time to comment.

[@captaintruth3219]

You should really think about doing a re-edit in the beginning you’re stating that the Springs job is to push down? It’s actually the springs job to push up and the diaphragms job is to push down at the right moment when the chamber is full of gas, in order to stop the flow to the engine.

[@steadyeddie7453]

You are partially correct. The metering spring does push up on the metering lever thus driving down the needle to close off fuel flow into the metering chamber. But the metering diaphragm can only push down and overcome the spring when the fuel level in the chamber lowers. Fuel level lowers as fuel is being drawn through other circuits and into the engine, then the diaphragm can push down the metering lever thus raising the needle and allowing more fuel to flow into the chamber, filling it back up.

[@ChopShopCustoms]

Thank you for posting this video it saved me from buying a new weed wacker

[@sequoyah59]

Thanks for the tutorial. Dang Chainsaws!!! ir right. Work two hours (if lucky) then work on the dang things for two days. I suspected it was diaphragms that cause the things to leak fuel like a screen door on a submarine. I have a high dollar Stihl blower and an equally high dollar Husqvarna brush cutter that simply run fuel into the crankcase and our of the air cleaner. I also have a 20 year-old Husqvarna blower from Lowe's that is at least 20 years old that can hang on the wall for two years and start with just a few pulls. It has a Kawasaki engine and must be a different carb than the other pieces of junk. One problem with lots of these engines is the fuel lines. They get lose and leak. So do the primer bulbs. Any crack, any air and the things will NOT RUN. We keep a hand full of each on hand to deal with cracked primer bulbs. Also, there are no clamps on any of the fuel lines.

[@israelrivera2830]

hello.I have a poulan pro pp4218avx.it wont start. Its got a new carb.new spark plug.and it does spark. I gap the ignition coil. But nothing. I checked the compression.dont know what else to check. Now i check the compression by putting my thumb on the spark plug hole. And i felt a slight resistance when i pulled the rope.im stuck!

[@ZombieDaveAZ]

Have you tried spraying carb spray down the throttle to get it to run for a second? You can even dip the spark plugs in gas and then replace it and pull til it starts . Try that and let me know.

[@israelrivera2830]

ulitepilot aka Zombie Dave .So I change the Fuel lines and also notice that the switch cable and the black cable had a smal slice in them.fix that and it started.

[@ZombieDaveAZ]

Feels good when you fix it yourself doesn't it. Good job. 👍

[@israelrivera2830]

@@ZombieDaveAZ yes it does!

[@terrymcclean4582]

Once again, thanks for the great video. I wish I'd paid this much attention when I was in school.

[@davessmallenginerevival2847]

Very good. Checks in the mail

[@atlred]

Great video, loved it..thank you !!!!

[@backtotraditional5698]

Outstanding walkthrough! I just rebuilt a MS 460 (new cylinder, piston, muffler, fuel and impulse lines) and put on a brand new stihl carb. I’ve been running slightly rich on the new cylinder and saw fuel coming out of the muffler when filling today. Is there any way a new stihl factory carb would have a diaphragm issue like this? I’ve always run non-ethanol and only use stihl mixing oil. I intentionally paid extra for the brand name to avoid cheap parts in the carb.

[@ZombieDaveAZ]

In your particular case it would probably be a good idea to pressure test the carb. There are videos on KZbin that will help you with that and give you the correct psi so as not to "hurt" the carb while you are testing on pressure and vacuum.

[@backtotraditional5698]

Thank you

[@steadyeddie7453]

Stihl bought Zama back in 2017-2018 and from that point forward all their carbs are made in China. It's stamped right on the carb.The local Stihl dealer has horror stories about brand new chain saws that wont start, start and die, and flood to the point of hydro lock. Many of the OEM Stihl parts come in packages labeled Made in China. I like to say that "Stihl sells one of the better chainsaws that China can make."

[@jerielbrown732]

100 procent good education

[@fastrivers812]

So, I just picked up my chainsaw from the shop because I couldn't get it to stay running. I originally had this fixed because I replaced the fuel filter but that didn't work for long. The shop said that the diaphragm was bad in the carb and it was just as cheap to replace the whole carb than to rebuild so I went w/ that option. I got there today and I heard them in the back trying to start it and it sounded like they had a hard time but they did get it to start. When I got it, there was a bunch of fuel on the exhaust which has never happened before prior to taking it in. I haven't had a chance to run it today but will when I get home. Could it be that they just flooded it? What should I look out for? Thank you.

[@ZombieDaveAZ]

Hey Fast, yeah I would just try to get it started first ibstead of looking for a problem that we are not sure exists yet. Gas out the muffler could be a carb issue for sure. Let me know what happens when you try to start it.

[@joseph5402]

Hey mate Thanks very much I bought a weed eater and it was doing this So I got a new dyafram And it works 👍

[@ZombieDaveAZ]

Now all the neighbors are going to be bringing you their carbs to work on. Good job buddy.

[@deewaby7291]

Hi dave watched your video iv changed the gaskets and it still happening will it be a needle or spring issue thanks.

[@ZombieDaveAZ]

Hi Dee, when you say gaskets I assume you did the diaphragms as well. The metering diaphragm goes after the gasket. Is that what you have going on? What is the condition of the little flaps on the pump side of the carburetor?

[@Doc-Cole_Trickle-of-Chainsaws]

Thanks for the video! How do you get the fuel out of the crankcase when this happens? Thank You, Darin

[@ZombieDaveAZ]

Remove the spark plug and flip it upside down and pull the rope. When no more fuel comes out it will still be in a "flooded" condition. Hold the throttle wide open and start pulling. It will start if you have compression and spark. 👍

[@Doc-Cole_Trickle-of-Chainsaws]

@@ZombieDaveAZ Thank You for your time and superior intelligence ZD!

[@MrMarineGomez]

Fuel coming out exhaust of my Husqvarna 120. New plug, new carb, same problem persists and no start. I’m using the 50:1 premixed fuel you buy in a gallon can. Seems like all my issues have a ya eyes after I ran my chainsaw with some of this stuff. Any thoughts?

[@ZombieDaveAZ]

Hey Cris, email me at [e-mail]. I can text you through the troubleshooting much faster than using KZbin. I do this a lot to help guys.

[@rwagoner56]

Very helpful! thanks

[@tonypagan7829]

i have an echo weed eater that dont start i took off muffler and cranked it and gas was shooting out is that the carb?

[@ZombieDaveAZ]

Yes. Its exactly what I describe in this video.

[@Vgp-rp4iu]

Ok so I have a poulan pl3816 and Everytime I pull to start it gas spews from the muffler and fills up the cylinder. I'm pretty sure it's the metering diaphragm but a whole new carb isn't much more than a 12 pk of them. Anyway my question is that when I search all I can find is carbs that fit a pp3816 or a p3816 but nothing to fit a pl3816. Are they all pretty much the same?

[@ZombieDaveAZ]

Here is the best way for me to describe it. PP3816 broken down is Poulan Pro 38 cc 16" bar, Pp3314 is still the pro model but 33cc engine and 14 inch bar. The carb should work as long as the first 2 numbers match your saw. Thats the engine size. I hope that helps.

[@ttttwwyu]

Is it normal to have a little gas, not a lot, coming out of exhaust? Carb tuned too rich or something? Thanks!

[@ZombieDaveAZ]

Not gas, oily residue will build up over time but not straight gas. I hope that helps Fred.

[@isidroizazaga2786]

Thanks good video

[@ZombieDaveAZ]

Thanks for watching. It was my pleasure. 🍺😷👍

[@cavalryscout8720]

Great information. Can debris blocking the needle from seating cause a similar problem?

[@ZombieDaveAZ]

No Mr Scout. The jets are always open to some degree. The low speed is open enough to run the saw at idle. Then the low speed works in concert with the high speed jet when in full throttle operation. If either jet was clogged or closed you would have multiple scenerios of problems. Either way the fuel must get past the metering diaphragm before it gets to the jets. I hope this helps. Stay safe and thanks for stopping by.🍺😷👍

[@ZombieDaveAZ]

After reading your comment again, yes. If the needle cannot seat it WILL allow fuel to run unobstructed into the engine. You are correct in your diagnosis. 👍

[@steadyeddie7453]

Theoretically yes. But the fuel flows through a fine mesh screen in the metering cavity before it arrives at the needle and seat. So if debris is so small that it passes through the mesh screen then it will also pass through the needle and seat. Now if the mesh screen was missing or installed improperly...

[@cutthetvoffman6317]

Nice video. This was a big help!

[@ZombieDaveAZ]

Thank you brother

[@tobyrodock7200]

No primer bulb on this model

[@ZombieDaveAZ]

Toby Rodock looks like a carb kit or replacement then. Double check those fuel lines

[@jsimm4587]

I’ve fuel coming out of the decompression valve not noticed exhaust could this be my issue ?

[@ZombieDaveAZ]

Absolutely yes. Decompression valve tells me it's a big bore machine like a chop saw. Without that valve it would be close to a hydro lock situation. Good find and address the carb situation and you will be good to go. Stay safe. 🍺😷👍

[@jsimm4587]

It’s a dolmar 7900 hadn’t ran for a long time I guess . I cleaned the coil and where it mounts got a new plug cleaned the carb and it fired off for about 10 seconds then died the carb it now dry and everything seems ok but it’s not getting gas to go I guess the carb has plugged up again it will run if I prime it with fuel but won’t keep running the high and low don’t seem to change things . The L was 7/8 out and the H was 1 I may go for two on both but I’m not getting any fuel so I’ll clean it again ! That for the reply and thanks for your video !

[@jsimm4587]

Also put the torch to the muffler and it was pretty soaked and burnt for a 1/2 hour !

[@ZombieDaveAZ]

@@jsimm4587 that would make sense that the metering diaphragm is hard. First stuck in the down position and allowing a ton of fuel in. Then stuck in the up position and it won't lean on that little arm that allows fuel in. Change that metering diaphragm.

[@jsimm4587]

You know how things are !! I started taking the carb off to clean check got one screw out and thought , check the gas and there is none ! Put fuel in and screw back it fired right up but wanted to quit but wound up good but ruff idle and then wouldn’t adjust no matter where I turned the L-H it stopped taking fuel and just idled just big out I’m scratching my head and I see the plus line disconnect so I put it on and I can’t get it to go again I’m stoppin for the evening but when itvran it ran good kinda ! Came s long way 2 days !! Kinda stunk that one up !! I didn’t make it to the diaphragm that time tho ! I will !

[@leeisenberg]

What the highest pressure you've ever seen compression testing a small engine? So far for me; 110psi.

[@ZombieDaveAZ]

I see 150 quite regular on chainsaws. Always run the test with the throttle open and about 3-4 good pulls.

[@ZombieDaveAZ]

Actual chainsaw with this exact symptom watch it all here kzbin.info/www/bejne/p17acmhqm6ybgKc

[@carvinlambert6899]

If a chainsaw has a Scored Cylinder, it will Flood the Cylinder and drown out your Plug.. remove plug and tilt engine down to drain. It's not the Coil, and it's not the Diaphragm. Don't go out and replace the Carburetor or the Diaphragm. It's your cylinder .

[@ZombieDaveAZ]

Perhaps if you do a more in depth explanation to explain how the gas actually gets into the cylinder I could understand your thought process. The ONLY way for fuel to get to the cylinder is via the crankcase first and then up thru the transfer ports to the combustion chamber. So there's that....... Zombie Dave

[@pepino735]

Maybe Proprietary Mixture, body

[@MikeNBikes]

I wish you didn't zoom 500x to where you cant see shit

[@dongkumong]

play this video at 1.5X, you'll forget this dood talks in slo-mo

[@ZombieDaveAZ]

Dude, not dood. C'mon.. stay safe and glad you learned something. 🍺😷👍

[@ramiroarizmendi9246]

Is this the same for atv’s..?

[@ZombieDaveAZ]

No. ATV's utilize a bowl type carburetor that is gravity fed.

[@ramiroarizmendi9246]

Any idea why it does this tho ...?

[@ZombieDaveAZ]

Why it does what?

[@ramiroarizmendi9246]

Spti raw fuel out the exhaust

[@ZombieDaveAZ]

@@ramiroarizmendi9246 2 stroke or 4 strok?e

[@paulorlando1603]

Well. If I knew enough to get to those and remove them, I pretty much wouldn't need this video. Wondering why you didn't show opening up the engine so I could get to them.

[@ZombieDaveAZ]

Well Paul, you pretty much answered your own question. You don't know enough to to get to them. That's why. If you are sincerely looking for help, you can phrase your question a lot differently. For example, "Hey Zombie, do you have any other videos that could help me with my problem? I'm kinda new to all of this. Thanks in advance, Paul." Try something like that and you will get a much more favorable response out of me.

[@paulorlando1603]

@@ZombieDaveAZ Touché. In my defense, if I did know enough to get to them, I likely would know these were the problem, and wouldn't need this video. ; )

[@ZombieDaveAZ]

@@paulorlando1603 help me help you out and tell me what kind of machine we are working on. This type of carburetor has many applications. Chainsaws, hedger, weedwackers ,blowers etc. You can also email me [e-mail]. I'll more than happy to help you out.👍🍺

[@paulorlando1603]

@@ZombieDaveAZ Thanks for offering to help, Dave-despite my smartassery. I am working on a Toro string trimmer head, an older one that fits all of the Trimmer Plus/Ryobi attachments. I went to start it, and gas (maybe a bit thicker than gas) sputtered out of the exhaust. Trid it with choke on and half-throttle, and everything sounded normal, but a stopped right there. It's had a cracked primer bulb for some time, but it never seemed to affect it-still started and ran normal in that condition. I know my first order of business would be to fix that first, if the engine is fixable. I've done a couple of successful repairs on in the past (minor things like a previous cracked bulb, fuel lines, and minor carb work), but this latest issue seemed like it may be from the cylinder or something.

[@ZombieDaveAZ]

@@paulorlando1603 I'd gas is coming out the muffler it is definitely a carb issue and usually it's the metering diaphragm. Not always but 90% of the time. I will follow this up with a link to another video to help you track this down.

[@captainsledge7554]

Someone doesnt know how a carb works.

[@ZombieDaveAZ]

Thanks for commenting. Waiting for your video on how a carb works to post brother. I subbed you.(at least for now)

[@captainsledge7554]

Its an impulse carb. The diaphragm pumps back and forth. Soon as they come into contact with fuel they become softer. Thats when theyre broken in. The diaphragm doesnt just sit there and hold the valve open it pulses back and forth. Your diaphragm on the left is good. The process your putting to this is how it works on a car. However its completely different. There is a hole in your intake that drives the impulse fuel pump in the carb. Which is your flap diaphragm up top. The positive pressure from the impulse port on ur intake starts the process, not vacuum. I stumbled across your video while double checking a diagnosis and i admired your attempt, but most people dont know that these carbs are impulse carbs means they dont work off vacuum they work off positive air volume. What causes excess fuel actually has to do with a stuck needle, improper adjusted metering arm, or an improperly aligned impulse port. I dont make videos lol

[@captainsledge7554]

So your repair worked, because you were affecting the other issues in your work.

[@captainsledge7554]

That port is always below your intake port. And in the xyli der it has a passage so that the entire down stroke of the piston creates a pulse of positive air. As the piston goes up, the valve flap in the top of the carb closes not allowing it to be affected by vacuum. As the pressure rises more rushes past the needle which fills up the "bowl" for lack of better term, which pushes the diaphram down under pressure, so being soft doesnt make a difference, its when they stiffen up that it fails. In sure you have found some crusty hard stiff diaphragms. Those are failed diaphragms. A soft one just means a richer amount of fuel is all. So now that fuel is in this bowl, the piston begins its up stroke, this closes the flap diaphragm, and the vacuum draws fuel from that bowl. Once the proper mixture is drawn, the diapghram then applies pressure on the needle opening it up for the next impulse. On a car its a bit different as you have a fuel pump. On an impulse carb, the pump is the entire top half of the carb, in junction with the engine. An improperly placed carb gasket or leaky carb gasket will cause that flap to stay open. When this happens, it then begins to suck fuel in thru the impulse port. This all happens very quickly thats why a 2 stroke idle is anywhere from 1400 to 1900 rpm and the max rpm ive seen range up to 17,000 rpm. If ive explained this like crap, take what ive laid out and draw a picture and watch videos on impulse carbs. You seem mechanically inclined enough to figure it out from here. That impulse port has to be perfect. If the gasket is misaligned then you will not have enough vacuum to pull the flap closed. Another thing that often causes over flow, is a bad check valve in the bowl. Its a brass fitting with a tiny hole in the center. Push a piece of fuel hole to that and suck. You shouldnt be able to suck, but if you blow it should open. Often times thise are stuck from oil grime and just working it a few times will fix it. Ppl often accidentally fix it when cleaning it with an air chuck or carb cleaner.

[@ZombieDaveAZ]

@@captainsledge7554 kzbin.info/www/bejne/oIilo5hqYtl7qck