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I thought that you adjusted the throttle stop screws to set your idle speeds? On my '97 Ski-doo Formula 500 carbs - it calls the air bleed screw a "idle adjustment screw". Can someone help me understand the difference and how they work together ? My throttle stop screw is turned out 4 1/2 turns while my idle adjust screws (aka air bleed screws) are turned out 1 1/2 turns. Which way makes the air bleed screw richer - in or out ?
 

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Is this a round slide Mikuni carb we're talking about??
 

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Air screw adjusts amount or air to mix with the pilot fuel. Idle stop sets how deep the slides sit in the carbs.
 

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The idle screws (larger screws with the springs on them) pretty much set the idle speed. Those are normally around 2 full rotations in from first contacting the carb slide (which starts at totally bottomed out in the carb). The further in you go (usually clockwise) the higher the idle.

The pilot air screws (small brass screws) fine tune the mixture at idle. Those are normally adjusted somewhere around 1 to 1.5 turns out (normally counter-clockwise) from lightly seated. On these, turning them out leans the mixture (and in richens it).

Hope that helps.
 
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