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[Cranky]

So i thought this slide adjustment thing was good fun so i soldered up the opposite edge to the cut out--- i had bit of time before the bar opened.
So yeah soldered up a 2 mm wall on the bottom. Guess what happened?

[Beezabryan]

The bar was closed and all the girlies had gone home to their parents.

[Cranky]

The bar was closed and all the girlies had gone home to their parents.

Hey ---how did you know that. Actually the bars are open but most of the girls have gone home to look after thier kids.

But you were pretty close.

[Presto]

"More air equals a weaker mixture".
But why?
It's not simply because the the quantity of fuel/air alters but with a slide its the way that this alters that is important. It's not simply that there is more air - it is that there is less fuel!

Place a thumb over a garden hose and you alter the force of the water. If your thumb makes a smaller hole the water comes out faster, with more force and travels further. Reducing the size of the opening increases the force of the water flow.

This is how a carburettor slide works. Reducing the cutaway increases the flow of fuel. A smaller cutaway gives a richer mixture, a larger cutaway a weaker mixture.

The amount of air entering the engine during the first ¼ of throttle action is determined by the slide’s straight edge.

The amount of fuel entering the engine at this throttle opening is determined by the slide’s cutaway.

Air flowing through the carburettor draws fuel up through the pilot and needle jets into the carburettor.

A larger cutaway results in a slower flow of air flow, drawing less fuel into the mixing chamber and creating a weaker mixture.

A smaller cutaway results in higher air velocity, more fuel is drawn into the engine richening the mixture.

[Cranky]

I read that place you thumb on a garden hose on the internet too. I don't see the connection myself.

Fuel is sucked out of the needle jet by depression depending on how high the fuel has to be sucked up the needle jet from the level of fuel in the bowl --IE float level.

[Presto]

Cranky you're not right about this.

Fuel is drawn into the mixing chamber by depression. The depression that acts on the jets is governed by the speed of air flowing through the venturi.

Reduce the area and air will flow faster - look at a narrow river.
Increase the area and air will flow slower - ditto.

The faster the air flows the greater the depression it creates and the greater the amount of fuel is drawn from the float chamber into the mixing chamber - smaller cutaway = richer mixture .
It's physics.
Not a matter of opinion.

[Cranky]

Cranky you're not right about this.

Fuel is drawn into the mixing chamber by depression. The depression that acts on the jets is governed by the speed of air flowing through the venturi.

Reduce the area and air will flow faster - look at a narrow river.
Increase the area and air will flow slower - ditto.

The faster the air flows the greater the depression it creates and the greater the amount of fuel is drawn from the float chamber into the mixing chamber - smaller cutaway = richer mixture .
It's physics.
Not a matter of opinion.

Well of course it is. I don't see how ive managed to cause confusion over this. What you said is certainly not in dispute.

[Presto]

Just for the sake of it - but always thinking I might be wrong!