It's almost impossible to locate and keep a screw driver on the idle mixture screw
of the World Formula while the engine is running. The location of the screw and
the engine shaking make it next to impossible.
This driver is made to fit on the World Formula idle mixture screw and stay there.
Simply place it on the screw and apply upward pressure and start the engine.
Continue to apply upward pressure while adjusting the idle mixture.
