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Discussion Starter · #1 ·
Is it just my luck,,,or are these things very hard to get right?? And I am choosing my words carefully and being nice. lol

Seems the bowl leaks ,,or it isn't filling the bowl,,,or no leaks and the float/needle/seat is not working and flooding the throttle body.

Over the last few months,,,Tecuseh carbs have been giving me more problems than anything.
 

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Can't say I've had any problem with Tecumseh OEM carbs, but I've got one Oregon aftermarket that's been giving me grief.
 

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Jack of All Trades
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Takes a bit to figure them out, but once you get get it, they are not that bad. I ALWAYS replace the emulsion tub and o-rings, and it seems that once you put gas in a rebuilt one if you have to pull the bowl again, even 1 day later, you need a new bowl ring. OEM, aftermarket, hasn't mattered, those suckers swell up quick.
 

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The Rubber o-ring swelling is due to ethanol in the gas..any ethanol content = swelling.

But all carbs are touchy, seeing as an engine will only operate correctly at or very near the stoichiometric air/fuel ratio of 14.7:1. And given that ethanol content throws off that ratio (requires more liquid fuel), and given that most carbs today are fixed jet...it makes things more difficult.

The needle and seat is pretty much the most simple part of a carb, and it either works or it doesnt.

If the float has a pin-hole or leak..even something miniscule, it will make it not work. a spec of debris between the needle and carb body, will make it not work. Any flaw on the rubber seat, even a tool mark from installation...will make it leak.

But when its all put together right, and clean...the carbs work under the same principle as all other carbs...low air pressure that drafts fuel up the emulsion tube and into the venturi and air stream...
 

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and "they" want to up it to 15%. i sure hope it gets shot down! 70% of our work is fuel related, 20% is actually mechanical and/or maintenance, and the other 10% is from the owners stupidity. Granted 15% would surely increase our business, but I DON'T want to see that because it will come at the cost of the customer due to invalidated warranties and the fact they have no other fueling options, other than Tru-Fuel, which is cost prohibitive in most cases.....

...never thought about it until now, but the 14.7:1 ratio is at sea level. We are at 1400-1500 ft. I wonder if that contributes THAT much to our "success" rate with non-adjustable carbs? (not in the repair end, but getting them to run properly)
 

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Discussion Starter · #6 ·
Well I rebuilt many carbs lately and only had problems with the ones on a Tecuseh engine.(3 of them to be exact.) Had to tear them ones apart several times,,,2 of them finally got correct ,,the other was a loss. And yep,,I think I bought every bowl gasket my parts dealer had in stock.

I was starting to think these things were junk,,but maybe,,,just a isolated problem at my place. And I am having very bad luck with the odds.

If you can see my point,,,it makes me a little skittish when I see a Tecuseh. Considering 4-5 other carbs,,I had no problem with.

No fear,,,maybe the next will go smooth.
 

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Why not buy O rings that will not swell when exposed to ethanol???

Viton O Rings should work great, and you'd never have another problem with 0-rings again.


I need various types of 0-rings when working on different types of pumps...


http://www.marcorubber.com/material_chart.htm
The o-rings that go on the emulsion tube are standard 1/8 x 1/4 so those you can get in Viton. But the bowl ring is more of a square ring, and I doubt you can find those except in Tecumseh or aftermarket numbers.
 

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Discussion Starter · #9 ·
If I had not seen the way the bowl gasket swells up I probably would not believe it. lol

The first time it happened (with a brand new gasket),,,after it was on for a day or two. I had to remove bowl again. I went to put it back together and thought I had picked up the wrong gasket off the bench. DOH!! Terrible!!!

A new design is in order. One that is flat and bends with the contour of the bowl.
 

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Tecumseh Carbs = Satans Masterpeice!..


--Nothing will mess with your head more than a Tecumseh carb,except maybe a woman...out of hundreds I have had,I think 50 worked "good"...some just cant be fixed ,I have concluded...especially after they sat with old gas in them "forever"...
 

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Discussion Starter · #14 ·
Tecumseh Carbs = Satans Masterpeice!..


--Nothing will mess with your head more than a Tecumseh carb,except maybe a woman...out of hundreds I have had,I think 50 worked "good"...some just cant be fixed ,I have concluded...especially after they sat with old gas in them "forever"...
What do you mean??? I was getting the impression that they are no different than any other. Your the first to somewhat agree with me.

I have not run across one yet that I didn't have to tear back apart,,,at least 2 times.
 

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Discussion Starter · #17 ·
I weeks ago I was in the city where they made the engines . Can't remember the name of it. Me and my girlfriend had lunch, at a little diner ,right in town.

I seen the place where the factory's used to be. A local started pointing and explaining how it used to be.

Oh,,ya ,,I remember the name of the city now!! It was Tecumseh, Michigan. LMAO

Southern part of lower Michigan.

RED: You can have them. lol

When I order the next carb kit for one. I will skip the hassle of going back later,,,and order new float,pin,,extra needle and seat,,,3 bowl gaskets and new adjustment needles. If I do that,,I might not need to go back to the parts dealer for more parts.
 

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Don't forget the emulsion tub. Seems like every time I skimped on that I regretted it and had to go back in and replace it anyway. Now its mandatory & only 1 out of ever 25 or so give any kind of problem, usually because of me rushing things and not getting it totally clean.
 

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Keep up the discussion guys, I'm learning.

I was thinking of tackling one off an 8 hp Tecumseh, after I get this 10 hp running...hopefully IT doesn't need the same job done.

Anyone use the Tecumseh carb tool?

It sounds like you can't over clean them things.
 

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Anyone use the Tecumseh carb tool?
It's a must-have tool, especially for seating and removing those little 'donuts' and leveling the float.
 
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