Tecumseh surging
#1
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Tecumseh surging
hi look i picked up a riding mower from a friend of mine and its driving me crazy trying to figure out whats wrong with it he told me it sat up for about two years without running it so i started out changing the spark plug new air filter new fuel filter new battery i drained the old gas out i took the carburetor apart found there was water in it so i cleaned that out i changed the needle and seat but it continues to rev up and down and backfires someone told me to clean the magneatos which i have done but no difference its a 13'5 tecumseh i have no problem starting it or it dying anyone with info would be much appreciated
#2
First welcome to the forum.
Second you have hooked on to a thread that is 10yrs old(most people won't look at it).
Third you need to post the numbers for the engine usually stamped in the shroud by the spark plug.
Now I will guess and say the problem is the bowl nut(main jet) it has several holes in it depending on the style, there is a tiny hole at the top on most that is usually the problem(almost invisible on some) I clean it with the wire from a twist tie. Have a good one. Geo
Second you have hooked on to a thread that is 10yrs old(most people won't look at it).
Third you need to post the numbers for the engine usually stamped in the shroud by the spark plug.
Now I will guess and say the problem is the bowl nut(main jet) it has several holes in it depending on the style, there is a tiny hole at the top on most that is usually the problem(almost invisible on some) I clean it with the wire from a twist tie. Have a good one. Geo

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Done that today there was one hole clogged cleaned it out but still having the same problem I may leave the carb soak overnite and try again hopefully that helps but thanks I'll put the numbers u need on tomorrow
#5

I have a couple of small Tecumseh's and both of them had Carb trouble.
One had a hole in the float. I found out that was real common with the Tecumseh engines.
Also its an unusually efficient design in the carb, no adjustable jets.
But it has little tiny passages that clog. Some are hidden under little rubber plugs.
With both my Carbs, soaking them overnight in Chem-tool solved those clogged holes.
An aside:
Did you ever wonder how those tiny little holes were made into the Carb's?
I wonder if it's a drilled hole or some other way?
Anybody?
One had a hole in the float. I found out that was real common with the Tecumseh engines.
Also its an unusually efficient design in the carb, no adjustable jets.
But it has little tiny passages that clog. Some are hidden under little rubber plugs.
With both my Carbs, soaking them overnight in Chem-tool solved those clogged holes.
An aside:
Did you ever wonder how those tiny little holes were made into the Carb's?

I wonder if it's a drilled hole or some other way?
Anybody?

#7
That engine has a series 7 carb which are a little different from other Tec carbs, the easiest repair is to replace the bowl assemble, snap the old one off and the new one on and you are finished. The "O" ring behind the main jet is usually the problem, it flattens out and shuts off the fuel flow also the "O" rings on the nozzle also crumble and leak, finding the proper size "O" rings can be a problem. Below is a link for repair instructions. Have a good one. Geo
Disassembly, Cleaning and Repair of Tecumseh Series 7 Carburetor
Disassembly, Cleaning and Repair of Tecumseh Series 7 Carburetor
#11
Surging is normally a lean condition, while it is running spray/dribble some brake parts/carb cleaner behind the carb and along the intake mating surfaces if the engine tempo changes you have an air leak and can take the appropriate action. Have a good one. Geo
#13
Did you transfer a part from the old carb to the new one? Surging is from not getting enough fuel. The carburetor delivers the fuel. If the gaskets and seals from the carb to the engine are good and sealed, then the carburetor is pretty much all that is left.
#14
Hello Keith,
Try to stabilize the engine R.P.M. by holding in one position the solid link between the governor arm and the carburetor throttle, using a pair of pliers or your fingers.
If the engine R.P.M. stabilizes, the governor or governor adjustment should be checked.
Governor adjustment procedure;

Good Luck
Try to stabilize the engine R.P.M. by holding in one position the solid link between the governor arm and the carburetor throttle, using a pair of pliers or your fingers.
If the engine R.P.M. stabilizes, the governor or governor adjustment should be checked.
Governor adjustment procedure;

Good Luck