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fuel/air screw on 2 strokes .....


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Been so long that I had a 2 stroke I forget which way to turn it for what but my guess is ....

out for more air in for more fuel ?

and 4 strokes it is called a fuel screw and is just the opposite

....this all correct ?

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Been so long that I had a 2 stroke I forget which way to turn it for what but my guess is ....

out for more air in for more fuel ?

and 4 strokes it is called a fuel screw and is just the opposite

....this all correct ?

Lean is out / Rich is in on my 2t

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If the screw is located between the slide of the carburetor and the cylinder, it's an air screw. If it's between the slide of the carburetor and the airbox, it's a fuel screw. Air screws lean out as you back them out, fuel screws are the reverse.

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I want to jump in here because I am always a tad confused here too. The "air screw" on all my carbs function by adjusting the height at which slide drops down, screw it in and the slider can't get down as far and so creates a bigger gap underneath it letting in more air/fuel mixture. To me this screw is simply an idle adjust.

Simple.

but the other one does not make sense to me.

Anyone want to tell me how to tune in the other adjustment feel free!!

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If the screw is located between the slide of the carburetor and the cylinder, it's an air screw. If it's between the slide of the carburetor and the airbox, it's a fuel screw. Air screws lean out as you back them out, fuel screws are the reverse.

On my '05 cr125 the screw is between the slide and the airbox and I think rich is in and lean is out, air screw right?

I want to jump in here because I am always a tad confused here too. The "air screw" on all my carbs function by adjusting the height at which slide drops down, screw it in and the slider can't get down as far and so creates a bigger gap underneath it letting in more air/fuel mixture. To me this screw is simply an idle adjust.

Simple.

but the other one does not make sense to me.

Anyone want to tell me how to tune in the other adjustment feel free!!

The screw you are referring to is the idle adjustment, the other screw should be your mixture screw.

Heres a very helpful link that rolandk posted in my thread:

http://www.maximausa.com/technical/l...summer2001.pdf

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