this post was submitted on 29 Apr 2024
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What is this thing?

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Small metal object with clip on top. Clip spins around the object body and can be attracted to a magnet (so made of steel probably). Object body does not react to magnet (so made of brass maybe). Cone shaped tip seems to be made of some kind of plastic.

Found this in my back yard, probably from something I was working on, but it doesn't look familiar.

What is this thing? (Identification may help me fix something I don't know is broken!)

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[–] nonproductive@infosec.pub 17 points 6 months ago (1 children)

Looks like a needle valve. Possibly from a lawn mower carburetor ?

[–] lettruthout@lemmy.world 6 points 6 months ago (1 children)

Yeah, maybe, but not one of my projects since I'm lazy and have a gardener do "mow and blow" on the yard. Will ask him though.

Thanks for the idea.

[–] Blue_Morpho@lemmy.world 4 points 6 months ago

It's definitely the needle from a mower carburetor. I just watched a YouTube video on cleaning a carburetor and it was exactly that.

[–] Nougat@fedia.io 17 points 6 months ago* (last edited 6 months ago) (2 children)

I figured I would throw in some more explanation about how this works.

The container in the carburetor which holds gasoline is called the "bowl." Inside this bowl, there's a float - one or two sealed metal or plastic pieces that will rise and fall with the level of fuel in the bowl.

The float is attached to a little metal tang. In this case, I believe that tang would have a hole in it that the pictured item clips to. As the float moves up and down, that needle also moves up and down inside its "seat." When the float is at its highest, that rubber tip is against the top of the seat, closing off the passage for gasoline to enter the bowl.

As gasoline is burned, the level in the bowl drops, the float drops, and the pictured needle falls from the seat, allowing fuel to flow into the bowl.

This keeps the fuel level in the bowl at a specific height. If that level is too high, the engine will run too rich (too much gas in the air/fuel mixture), and if it's too low, it will run too lean. Low enough, and it'll stop running as though it's out of gas. Because the bowl is empty.

Gasoline gets pulled from the bowl by the intake air stream passing across a tube going down into the bowl. The intake air creates a low pressure, and sucks the gasoline out. As the gasoline comes out, it is atomized into the air, making it more combustible inside the engine.

[–] lettruthout@lemmy.world 4 points 6 months ago

Thank you for this clear explanation!

[–] BearOfaTime@lemm.ee 1 points 6 months ago* (last edited 6 months ago) (1 children)

Spot on.

Only no hole in the tang, the clip slides over the tang so the needle can free float as the float itself moves.

In this diagram, the float/needle/seat are #22-25

Also, (for OP) - the needle tip is made from a material softer than brass, so it wears out before the seat, since it's easier to replace.

[–] Nougat@fedia.io 2 points 6 months ago

I’m more used to motorcycle carbs where that needle has a post with a spring under it.

[–] Fosheze@lemmy.world 11 points 6 months ago (1 children)

As others have already said. Thats a needle valve from a carburator. Theres no question about it. It also isn't something that falls out. Someone did some lawnmower repair and either was annoyed when they lost it or just pitched the old one in your yard when their parts kit came with a new one. There's probably not much point in saving it though because they're dirt cheap and easy to get. Whoever lost it has almost certainly replaced it by now because without that little needle the carburator won't work and will start pouring gas everywhere.

[–] lettruthout@lemmy.world 3 points 6 months ago
[–] Hayduke@lemmy.world 10 points 6 months ago

Float needle valve for sure.

[–] Chainweasel@lemmy.world 9 points 6 months ago

That's definitely a needle valve for a carburetor.

[–] kensand@sopuli.xyz 5 points 6 months ago

Looks a lot like a carburetor float needle to me. It allows the flow of gasoline into the float bowl, which sets the amount of fuel fed into the engine.

It's common for float needles (and carb parts in general) to be made of brass, and the wire clip being made out of steel is also consistent with a float needle. The plastic tip is probably used for a better seal when the float is up, closing the needle port.

[–] EdibleFriend@lemmy.world -1 points 6 months ago

/c/sounding