Air mixture screw. Carb question

Shawn Martin /

The Streetmates standard air mixture screw setting is 2 rotations from Closed. Closed sounds like it means screwing the screw all the way down clockwise until it stops. What confuses me is Clockwise on the screw is RICHER. Closed doesn't mean richer right? I know I can just adjust for the highest RPM but I want to know what screw position is considered CLOSED.

Re: Air mixture screw. Carb question

Closed is all the way in until it does not turn anymore - just do not do "in" as super tight

Re: Air mixture screw. Carb question

Fully seated is considered closed. As in, turn the screw clockwise, to the right, until the screw seats itself. Fully.

Then back the screw out, counter clockwise, to the left, two revolutions.

Depending on which side the Air/Fuel mixture screw is located on the carb will determine whether turning the screw in or out will make the mixture richer or leaner.

Re: Air mixture screw. Carb question

Carbs have two type of metering adjustments: air metering and fuel metering.

If you screw in a fuel metering screw the mixture will get leaner as you screw it in.

If you screw in an air metering screw the mixture will get richer as you screw it in.

You say that screwing in the screw gives you a richer mixture, so that sounds like it is an air metering type.

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