# Tecumseh carb leaking



## John Lolli (Nov 3, 2005)

It is a 640350 carb on a tecumseh engine. I have taken it apart and cleaned it 3 times and installed 2 needle/seat kits plus a new float. At first it doesnt appear to be leaking however after leaving it overnight, it is leaking. I have also tried adjusting the float and the clip that holds the needle is pointing toward the air filter side. All suggestions are appreciated.


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## jsouth (Jan 31, 2008)

When you installed the needle and seat.There is a smooth and a grooved side on the seat.The seat must go with the grooved side down.The needle sits on the smooth side.You might have put the seat upside down twice.That my luck.Hope this helps.

Jerry


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## John Lolli (Nov 3, 2005)

jsouth thanks for the response -- yes it was installed with the groove side down


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## 30yearTech (Sep 14, 2006)

Could possibly be the float, I have run across carburetors with seemingly good float's that refused to stop leaking. New float, no more flooding. A couple of other things to check, the atmospheric vent into the float bowl for your carburetor. A restricted vent can also cause a flooding condition. A bad fuel cap on the fuel tank can sometimes cause a carburetor to leak over time, loosen the cap and see if it makes any difference.


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## John Lolli (Nov 3, 2005)

30year - thanks for the response. I tried a new float (rotary products) and it still leaked. The third time I tested it I did a bench test so the cap was not a factor. I have a small rig to do this. Where is the atmospheric vent on this carb. It is either a 640350 or a 640271 which the 640350 supposedly replaced. The carb has 5213 stamped on it.


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## 30yearTech (Sep 14, 2006)

Try this link, I believe this is the series carburetor you have. Pretty good detail for a rebuild.

http://outdoorpowerinfo.com/repairs/tecumseh_series_11.asp

If you used a new float, did you set the float level?


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## John Lolli (Nov 3, 2005)

That is a great article and yes, it is a series 11 carb - thanks. I actually have the gap between the float and the carb body (lip for the bowl gasket) a little more that 11/64. The thought being that the gas in the bowl would push the float up with more pressure thereby providing a better seal of the needle and seat. I have not removed the bowl to access the bowl vent however I did blow air through it with my compressor. Maybe that is the problem. Before I remove the primer I will check to make sure air is coming out of the vent when I push the primer.


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## John Lolli (Nov 3, 2005)

Ok I am back to working on this carb. I set the float to be 11/64 above the body. I will let it sit overnight on the bench test and see if it has leaked in the morning. I took a look at other tecumseh carbs I had in the shop and none of the floats were sitting 11/64 above the body. They were all higher ????? 11/64 is actually less than 3/16 and that seems awfully low to me however this certainly would not be the first time I was wrong on something.


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## John Lolli (Nov 3, 2005)

Well, I cleaned the atmospheric vent and set the float to 11/64. I left it in test rig overnight and it did not seem to leak. I am doing additional bench testing today.


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