Key shut off won't work on snow thrower,need help.


I have an old Montgomery Ward, with a Tecumseh engine, snow thrower that keeps running when I take the plastic key out. I turned it off by turning the choke down. I notice the other day that it was leaking gas ( I think from the carb) when the key was left in and seemed to have stopped when I took it out. How does the key work and is this something I need looked at or fixed??
Thanks
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snipped-for-privacy@gmail.com wrote:

Mostlikely just shorts out the magneto, as likely should happen when the throttle is moved to the very slowest position. AFAIK such keys are merely safety devices, to keep kids from getting hurt.
On such engines, nothing so sophisticated as key shutoff of fuel supply.
Fuel leak likely from leaking o-ring, like around main mixture adjustment, or leaking float valve, or perforate float. Carb-rebuild time.
J
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If it has a plastic key then it most likely has a metal contact inside that has lost some of its spring. Basically when you pull the key out the metal contact inside is suppose to touch the ground and short out killing the ignition. Since most people like to leave the key in for all these years the metal contact that is suppose to short out looses its spring and doesnt work right. You can remove it and bend it again to give it some spring again. Easy fix.
Now the carb problem.... You might have an issue where there is a little dirt in the needle valve. If the carb hasnt been cleaned in years I would bet that's the problem. I'd try cleaning it out with a little carb cleaner. Otherwise a small carb rebuild wouldnt hurt either. (basically clean it out and replace all the old gaskets) I would also check the float and make sure its not filled with gas. Sometimes they fail from a pinhole leak and the float doesnt work the way its suppose to anymore.
Tom
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snipped-for-privacy@gmail.com wrote:

of the throttle broke off. So we used to throttle down and then choke the engine to stop. Finally last year doing some other maintenance we reattached the wire and now we just push the throttle right down to where it contacts and shorts out the ignition. IIRC it is the same circuit that is grounded (shorted out to frame) by removal of the plastic 'key'? Our is a Tecumseh engine.
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Where do I find the float? I am just a user and know nothing mechanical.
Thanks

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The carb bowl is located on the bottom of the carb. It normally has a 1/2" nut on the bottom of it. I would turn off the gas (if it has a cutoff switch) If no fuel cutoff switch, just use a good plastic cup under the carb to catch the gas. Once drained you can take off the carb bowl. In there you might see some dirt on the bottom of the bowl, clean it out.
The needle valve is visible when you pull the float all the way down. The needle looks like a little metal pencil with a wire attached that connects to the float. Easy to get out, a little more tricky to get back in. Clean the needle valve off with a carb cleaner....
I can go on here about how to do a basic rebuild... Sound like something you want to do???? If not that's ok.
A quick way of taking care of a leaking carb can also be just to put in a fuel cutoff switch under the gas tank of that snowblower. That way when its off no more gas pours out. When you run it, its not much of a problem at that point because the gas is properly being sucked into the motor.
Tom
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I think you are relating the unrelated, the fuel leak was likely a result of shutting it off with the choke, and it stopped because it had leveled out, not because you pulled the key. The no shut off is as the other posters have explained probably due to the contacts separated by the key being tired & no doubt an easy fix. If the key enclosure is impenetrable, you could always replace the whole thing with almost any sort of a switch, a key switch preferable if youngsters are a problem. I bought a used mower that had a piece of spring steel bolted next to the spark plug, you push it with your foot to shut down, crude but effective.
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snipped-for-privacy@gmail.com wrote:

As other have said, the switch is nothing more than a simple shorting operation. Something (probably a spring) is no longer shorting out. Simplest fix is to just pull the wire off the switch and fasten it so you can just push it against the machine to make a short. A remote possible is that something has pulled the wire loose leading to the motor.
Harry K
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Lose the key and install a toggle switch. ON is off and OFF is on.
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