# 3.8 tecumseh engine problem



## Halfromeuropa (Jul 5, 2009)

Hi,
I am Hal from Granite City, Illinois.	

My daughters craftsman lawnmower was hunting. I bought a carb repair kit,
techumseh #632760B, to do the rebuilt. Disassembled carb and soaked in Gunk
cleaner for about 30 minutes. Carb did not look dirty before soaking. Replaced
o rings along main jet and seated it. replaced needle and seat. Made sure
throttle plate working/no binding. Gaskets were replaced and then put carb back
on engine. Engine now starts, but will barely idle. Black puffs of smoke come
out of muffler and gas sprays from intake throat opening. I noticed that if I
turn the shut off fuel valve off, engine revs and smooths out, then dies. I
also noticed that if I choke off the air intake throat, the engine will rev up
and smooth out. I don't know what I did wrong and am at my wits end. Can
anybody help out.
thanks in advance. Engine number is 143.963812


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## Rentahusband (Aug 25, 2008)

Did you clean the tiny holes in the bowl nut? There is one twords the end of the piece that is usually the culprit. It is angled downward, use the wire from a twist tie. Do you have gas running out of the carb when not running? Did you install the seat with the groove down and seat it all the way in?
Dean


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## 30yearTech (Sep 14, 2006)

Did you replace the primer bulb?

I cannot find a reference for the carburetor kit you listed, for the engine number you posted. What parts were in the kit?


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## Halfromeuropa (Jul 5, 2009)

Dear Rentahusband,
Yes I cleaned the float nut and the all 3 holes were open. I have not noticed fuel leaking from carb because I have a shut off inline. I turn the fuel off and allow the mower to die from fuel starvation. I also seated the needle seat with smooth side up.

Dear 30 year tech,
I did not replace primer bulb. I gently removed the hold down ring and removed the primer bulb before cleaning. The rebuild kit was purchased at a lawnmower shop, giving them the engine model number. The kit included several rubber o rings, i assume for main jet, several washers, (felt and metal for throttle shaft and float bowl nut ), couple of welsh plugs, needle & seat/clip and also large float bowl gasket.


thank you for both for responding. this is the most primative carb that I have ever worked on and it is driving me crazy. 

2 other things i forgot: I am noticing gas in the oil and also the first time that i tried to start the mower, i pushed primer 5 times, the fuel shut off was left open, (probably for a week). when I pulled the starter, i noticed gas coming from the muffler.


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## 30yearTech (Sep 14, 2006)

This would indicate that the carbruetor is flooding, either there is a bad float, needle and seat or possibly a plugged float bowl vent. 

When you replaced the O-Rings on the nozzle did you get all of the old ones out??


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## Halfromeuropa (Jul 5, 2009)

yes, i removed and replaced with new, both o rings on the main jet. top looked okay but bottom came out in pieces


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## 30yearTech (Sep 14, 2006)

Then I would look at the float and or needle and seat as a possible issue, and double check the bowl vent as well.


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## Rpeters123 (Oct 19, 2005)

*Your float has a hole in it -sinks*

Next time the carb floods take the float off -shake it- listen for gas sloshing inside. If you have spring on the float it may hold needle open- down if installed wrong. I leave them off sometimes.:thumbsup:


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