Carburetor trouble

viperv10

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Oct 7, 2016
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Hi guys, my church has a lawn boy with a Tecumseh engine (silver series 10202). It will start but will not stay running. It will keep running as long as i keep pushing the primer bulb. It sounds like a fuel flow problem. Does anyone have any idea what might be going on or what I should look for when I take off the carb and look at it? It has set for almost a year. Any help would be appreciated.
Thank you.
 

Rivets

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Time to remove the carb and rebuild. Kit #631021B plus new intake gasket. Here is the procedure I follow.


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.
 

viperv10

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Oct 7, 2016
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Thanks Rivets, I have some Tecumseh and Walbro parts. Some of the parts look a lot alike. My wife has a long fat needle that I put seats in with to start them,
then I use the bottom part of a drill bit to set them in good. I have rebuilt the carbs on the church's and my snowblower before. I just didn't know why it wasn't getting good gas flow. Something must be plugged up somewhere. I'm having the same problem with a 1980 lawn boy with a plastic carburetor. It ran fine
before I cleaned it. Now I have to keep on pushing the primer to keep it running. I soaked it in a gallon can of carb and parts cleaner and sprayed all the little holes out with carb cleaner and blew everything out with with air. I used a new gasket also so it shouldn't be sucking any air. Kind of weird. OK, back to the work shop. Thanks again.
Jerry
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
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64
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Thanks Rivets, I have some Tecumseh and Walbro parts. Some of the parts look a lot alike. My wife has a long fat needle that I put seats in with to start them,
then I use the bottom part of a drill bit to set them in good. I have rebuilt the carbs on the church's and my snowblower before. I just didn't know why it wasn't getting good gas flow. Something must be plugged up somewhere. I'm having the same problem with a 1980 lawn boy with a plastic carburetor. It ran fine
before I cleaned it. Now I have to keep on pushing the primer to keep it running. I soaked it in a gallon can of carb and parts cleaner and sprayed all the little holes out with carb cleaner and blew everything out with with air. I used a new gasket also so it shouldn't be sucking any air. Kind of weird. OK, back to the work shop. Thanks again.
Jerry

Lots of walk behinds have a filter built into the outlet which can get blocked with debris
Even without the filter, debris can still block off the outlet.
 
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