You should be an engineer brother! I admire your tenacity to do things thoroughly ! I am working on a very nice John Deere STX 38 with the Kohler Magnum 12.5 s engine .Walbro LMK 4 Carb . It was running fine until on steep hil ,starving for gas.So I disassembled carb ,cleaned,reassembled. I put it back together it started hard but fired up and ran good.Mowed my yard and decided to try adj air fuel mix . While doing that it died . Now it won’t run over low idle and very hard to start. Removed and cleaned carb several times thoroughly ,still runs like fuel starved.Cleaned gas tank ,fuel lines,shut off valve ,solenoid ,new filter. New ignition coil . My float needle does not have the black tip on it and does not have that brass seat yours has . I am beginning to think parts fell out or something . I am not new to this ,just have never seen this particular carb. Craftsman,Murray,mtd carbs are easy . Don’t know what I am missing ! Ready to buy new carb!
Thanks for the idea Don! I tried this and I noticed a scratch in the seat, so I took a drill bit and turned it by hand until the scratch was gone. Then polished it up with the q-tip in the drill. I filled a funnel and hose with water and had the carb sitting upside down over night with the float and needle installed and no leaks! I still might get the vacuum gauge to test it that way. I'm tired of the old Cub smelling of gas.
Your welcome. It's good to see someone else who is not afraid to clean or rinse a carburetor with water. I use 95% ethanol (grain alcohol) to rinse out the water when I'm done.
Thank you. Walbro also makes replacement nickel plated seats that eliminate the ethanol corrosion issue. Taryl shows how to replace one here: ua-cam.com/video/5JOgUxBU3MQ/v-deo.html
I think its the needle because the mower won't start up with it aiming up hill with it that way the needle shuts the gas off because the gas in the bowl lifts the float up that pushes the needle up So i can aim it down hill and it'll start right up its the second walbro i have that does this i think the needles are to small the rubber tip Mine are clean new just about
No it's corrosion in the needle seat from ethanol fuels. Gasoline is far more aggressive at cleaning than kerosene. Walbro makes newer needle seats that are nickel plated. They do not corrode in the presence of ethanol fuels.
Just get you some carburetor cleaning tools off the internet and then use whatever gas or rubbing alcohol whatever your comfortable with getting on your fingers those and a air compressor should work
Help someone. I have a LMH17 carb and it leaks during running. The needle and seat are fine. I'm suspecting the ATMOSPHERIC vent is clogged. Cant find a way to get to it. Looking for a crossection picture if it to find the vent hole. It leaks out the rectangular hole in the intake, where the choke arm base is.
A few suggestions here: www.google.com/search?q=lmh17+walbro+leaking+while+running&oq=lmh17+walbro+leaking+while+running&aqs=chrome..69i57.22657j0j7&client=ms-android-google&sourceid=chrome-mobile&ie=UTF-8
@@gregschroer2314 The pump just supplies vacuum or pressure. If you have the proper air tight tubing setup you should be able to test anything. Unfortunately, I'm not too familiar with 2-cycle carburetors to give you a definitive answer.
Wider seat? The cleaning process doesn't make the seat wider. Even better is to replace the seat with the newer Walbro nickel plated seat which does not corrode with ethanol fuels.
See its more of a needle problem my brass pieces are fine and clean but all of them have more of a id say a skinny needle rubber tip problem A other person said you can change out that brass seat and put a big or small one in one size is for the gas pump type of Kohler engines but taking that small part out can be hard is what he said a smaller one would work good on mine so it'll get less gas or a needle with a bigger rubber tip But those places who makes the carburetors know what they're doing wrong just like all the other cheap john deere stuff and stihl and poulan and Briggs they don't give a shit about they're products
The idea behind the video was to prove where the gasoline was leaking from with pressure testing. I was told it was leaking AROUND the seat which was not the case. The replacement of the seat itself is actually complicated. They are pressed in to the carburetor body. Most dealers will replace the whole carburetor before they rebuild one or replace the seat.
@@diverdon184 I just replaced two needle seats for both my lawn mower and snowblower, it wasn’t that difficult if you know what you are doing. My lawn mower was leaking fuel from the seat and fuel coming out through the carburetor, replacing the seat corrected the problem. The snowblower seat replacement is just a regular maintenance since I haven’t replace the seat for more than ten years.
Still wont be great again because all they need is the right needle not the seat The needles rubber tip is to skinny for the hole seat as that guy said too what i been seeing on all my walbros those needle rubber tips are wrong on Kohler walbro carburetors
You should be an engineer brother! I admire your tenacity to do things thoroughly ! I am working on a very nice John Deere STX 38 with the Kohler Magnum 12.5 s engine .Walbro LMK 4 Carb . It was running fine until on steep hil ,starving for gas.So I disassembled carb ,cleaned,reassembled. I put it back together it started hard but fired up and ran good.Mowed my yard and decided to try adj air fuel mix . While doing that it died . Now it won’t run over low idle and very hard to start. Removed and cleaned carb several times thoroughly ,still runs like fuel starved.Cleaned gas tank ,fuel lines,shut off valve ,solenoid ,new filter. New ignition coil . My float needle does not have the black tip on it and does not have that brass seat yours has . I am beginning to think parts fell out or something . I am not new to this ,just have never seen this particular carb. Craftsman,Murray,mtd carbs are easy . Don’t know what I am missing ! Ready to buy new carb!
I used brasso and a regular cotton swab in a drill and it worked! Thanks for your excellent video!
It works with an ear tip, saved my 27 years old carburetor thanks very much from France
Glad I could help....Je t'en prie!
Having the same problem , great video , so down to earth , just plain common sense , will be trying this with my carb asap , many thanks
A very in depth and original way of cleaning the float needle seat. Thank you.
Thank you Stewart.
Thanks very much for this excellent video and analysis of a difficult problem.
Your welcome. I hope it helps.
Excellent video!
Thanks for the idea Don! I tried this and I noticed a scratch in the seat, so I took a drill bit and turned it by hand until the scratch was gone. Then polished it up with the q-tip in the drill. I filled a funnel and hose with water and had the carb sitting upside down over night with the float and needle installed and no leaks! I still might get the vacuum gauge to test it that way. I'm tired of the old Cub smelling of gas.
Your welcome. It's good to see someone else who is not afraid to clean or rinse a carburetor with water. I use 95% ethanol (grain alcohol) to rinse out the water when I'm done.
i clean mine with water and dish soap then after that dry it off and blow out all the small holes
I am a carburetor man myself,all kinds,yep it works,has to seat and be clean!
Thank you. Walbro also makes replacement nickel plated seats that eliminate the ethanol corrosion issue. Taryl shows how to replace one here:
ua-cam.com/video/5JOgUxBU3MQ/v-deo.html
what positive pressure did you apply at which it held?
Try using an otoscope to inspect the seat.
I think its the needle because the mower won't start up with it aiming up hill with it that way the needle shuts the gas off because the gas in the bowl lifts the float up that pushes the needle up
So i can aim it down hill and it'll start right up its the second walbro i have that does this i think the needles are to small the rubber tip
Mine are clean new just about
Mine idles fine but chock on high throttle. Don't know if this is the same issue.
Just curious, if you soaked the carb in kerosene, would that accomplish the same thing???
No it's corrosion in the needle seat from ethanol fuels. Gasoline is far more aggressive at cleaning than kerosene. Walbro makes newer needle seats that are nickel plated. They do not corrode in the presence of ethanol fuels.
Just get you some carburetor cleaning tools off the internet and then use whatever gas or rubbing alcohol whatever your comfortable with getting on your fingers those and a air compressor should work
Help someone. I have a LMH17 carb and it leaks during running. The needle and seat are fine. I'm suspecting the ATMOSPHERIC vent is clogged. Cant find a way to get to it. Looking for a crossection picture if it to find the vent hole. It leaks out the rectangular hole in the intake, where the choke arm base is.
A few suggestions here:
www.google.com/search?q=lmh17+walbro+leaking+while+running&oq=lmh17+walbro+leaking+while+running&aqs=chrome..69i57.22657j0j7&client=ms-android-google&sourceid=chrome-mobile&ie=UTF-8
What is the pressure vacuum guage make and model please ?
www.amazon.com/dp/B01JRRIEBI/ref=cm_sw_r_cp_apa_i_kco8Eb0WWZNKK
@@diverdon184 does this model vacuum gauge work on two cycle carburetors?
@@gregschroer2314 The pump just supplies vacuum or pressure. If you have the proper air tight tubing setup you should be able to test anything. Unfortunately, I'm not too familiar with 2-cycle carburetors to give you a definitive answer.
Testing with water doesn't work. Gas is much thinner. A wider seat is not better. It would have a greater chance to collect contaminants.
Wider seat? The cleaning process doesn't make the seat wider. Even better is to replace the seat with the newer Walbro nickel plated seat which does not corrode with ethanol fuels.
@@diverdon184 the cleaning process doesn't make it wider but changing the angle does.
The entire carb was never meant to be serviced.
Why won't this video play?
You aint holding your mouth right
See its more of a needle problem my brass pieces are fine and clean but all of them have more of a id say a skinny needle rubber tip problem
A other person said you can change out that brass seat and put a big or small one in one size is for the gas pump type of Kohler engines but taking that small part out can be hard is what he said
a smaller one would work good on mine so it'll get less gas or a needle with a bigger rubber tip
But those places who makes the carburetors know what they're doing wrong just like all the other cheap john deere stuff and stihl and poulan and Briggs they don't give a shit about they're products
I'm leaving just wanted to say solenoid is stuck causing fuel flood
You make it sound too complicated, it leaked from the needle seat, just replace the seat with a new one.
The idea behind the video was to prove where the gasoline was leaking from with pressure testing. I was told it was leaking AROUND the seat which was not the case. The replacement of the seat itself is actually complicated. They are pressed in to the carburetor body. Most dealers will replace the whole carburetor before they rebuild one or replace the seat.
@@diverdon184 I just replaced two needle seats for both my lawn mower and snowblower, it wasn’t that difficult if you know what you are doing. My lawn mower was leaking fuel from the seat and fuel coming out through the carburetor, replacing the seat corrected the problem. The snowblower seat replacement is just a regular maintenance since I haven’t replace the seat for more than ten years.
@@shikpolam8968 I have replaced them also. The video describes cleaning the seat bevel so replacement is not necessary. Did you watch the whole video?
Still wont be great again because all they need is the right needle not the seat
The needles rubber tip is to skinny for the hole seat as that guy said too what i been seeing on all my walbros
those needle rubber tips are wrong on Kohler walbro carburetors