Old Lawn boy will not run

[colly43]

Hi
I have a 15 year old Lawn boy walk-behind mower that will run for 3-5 minutes and then dies. I pushed the bulb that feeds gas to the carburetor (No Choke) and it does run for a few more minutes. I have removed the float bulb, flushed out the gas, and that made it run for about 30 minutes. Now it's back to 3-5 minutes. It is a Tecumseh Products, ENGINE FAMILY- YTPXS.1851BA DISP 185CC. The name on the fly wheel cover is SILVER ELECTRIC START, 5.0 hp. It's a 21 inch mower.
Rather than changing parts I thought I would run it by you guys to any expert advice you can give me.
Colly43

 

[kbowley]

The fuel cap vent may be plugged, creating a vacuum in the tank, or the float is sticking. Try soaking the fuel cap in water and dish soap for a few minutes. If that fails, the carburetor will likely need to be replaced with an OEM. What is the model of the Mower? Also, that is not the engine model; it should be something like LEV185xxxxxx

 

[Tiger Small Engine]

The fuel cap vent may be plugged, creating a vacuum in the tank, or the float is sticking. Try soaking the fuel cap in water and dish soap for a few minutes. If that fails, the carburetor will likely need to be replaced with an OEM. What is the model of the Mower? Also, that is not the engine model; it should be something like LEV185xxxxxx

Clean existing OEM carburetor.

 

[colly43]

Thanks for input. I did the soap and water on the cap and that didn't help. Also unscrewed the cap as the engine was dying and that didn't help. I attached the engine tag as I cannot find any other information on the mower, except on flywheel cover noted above. I will pull the carb tomorrow and use Gum-out. How do I fix a sticking float? I had the sediment bowl off earlier and the float was moving freely.

 

[Rivets]

Please the model and serial numbers off the silver ID tag located on the rear of the deck. This will help us better see which engine you are dealing with.

 

[kbowley]

Does the carburetor resemble this one? Are you certain that is a lawn boy, not a
craftsman? Anyway, the bolt that holds the bowl in place should have the main jet holes. Remove the bolt, then clean the holes with a piece of fine wire and carb cleaner. Otherwise, you will need to remove it and thoroughly clean the carb. The mower chassis should have a silver decal on the mower housing, possibly under the bagger cover. Please send any identification you can, such as a photo of the top of the engine, the carburetor, and the entire chassis. Here is a video, is this what your machine looks like?

 

[colly43]

Hi Guys
Well Duh, now have the Lawn Boy model # 10361 and Serial # 210004991 plus photos of the carb as requested. The diagram that Kevin sent looks like my mower. The air cleaner is off for the carb photos. The sediment bowl, aluminum, has an indentation on about half the bottom. Is that suppose to be under the needle valve?
You have an interesting forum-love reading about all the problems people like me have with mowers, etc.

 

[Rivets]

If it came to me this is what I would be doing.
Needle and seat replacement.

Remove the carb, and then remove the float bowl. Check the float bowl jet (which is the bowl screw) and make sure the jets both horizontal and vertical are clean and open. Tip the carb upside down and remove the float pin and float with needle attached. Look in the float needle passage and you should see the red float seat at the bottom of the passage. This is where a #5 crotchet hook would come in handy as you need to remove this seat. If you have no hook, but compressed air, you can blow through the fuel inlet and try to pop the seat out. Put your thumb over the passage to prevent the seat from flying who knows where. No air or hook try bending a stiff paper clip to dig the seat out.

I would either give the carb a good 24 hour soaking or have it ultrasonically cleaned at this time.

With the seat out clean the passage way with carb cleaner. Now you must find a drill bit slightly smaller than the passage way, to be used to press in the new seat. Apply a very, very small amount of a very light lube to the new seat. 3-1 oil or lighter, to help seat it better. Carefully insert the new seat in the passage way with the rings on the seat down toward the carb body. Slowly and carefully force the seat down with the back end of the drill bit. Once it is seated, check to see that it did not flip and the rings are up. Next check to make sure that the float does not have any liquid in it. If it does, replace. If everything looks correct, attach the new needle to the float and install with the float pin centered. It everything is correct, the float should seat level to the carb body, when looking at it upside down. If everything looks good reattach the float bowl, making sure that both the bowl gasket and the nut gasket seal properly. Reinstall on the engine and test unit. Remember to have patience and take your time. Good luck, but I don't think you'll need it.

PS: On the side of some Tecumseh carbs you will find a plastic cover. Under this cover will be an idle jet. Remove it and check to see that the jet is open both horizontally and vertically. You should be able to push the old float needle wire through the vertical opening.
New float needle and seat, Tecumseh part number 631021, can be obtained at any good repair shop.

 

[StarTech]

That particular model and serial came with the Tecumseh LEV115-350180E engine. the carb on that engine is PN 640273. It should have casing number of 5210 on the carb body.

If not post what the casing number is.

 

[kbowley]

CARBURETOR NO. 640273. The link below has a breakdown of the carb.​

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