air/fuel screw

[Bolinracing]

On a 2001 400ex carb., does the a/f screw adjust the amount of air or fuel. I know some quads are different. If I screw it all the way in is that less air and backing it out is more air? Or is all the way in less fuel and backing it out more fuel? All the two strokes I use to ride were air screws. backing the out leaned it out. Is the 400ex the same?

[GPracer2500]

They are not the same. A 400EX carb has a fuel screw not an air screw. IN is leaner and OUT is richer on the 400EX.

FYI: Two stoke carbs normally have air screws and four stroke carbs normally have fuel screws. You can tell if a carb has an air screw or a fuel screw by it's location on the carb. An air screw will be on the intake side of the carb while a fuel screw will be on the engine side of the carb.

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