Fuel for the idle system is supplied to the idle well from the idle jet and a horizontal passage in the main well. The fuel then passes through the metered orifice in the idle tube. The metered fuel continues up the idle tube where it is blended with air from the idle bypass. Then, this mixture continues on through the idle channel restrictor.

A second metered quantity of air is introduced (show in view B) at this point, from the idle air bleed. This air-fuel mixture travels down to the idle transfer slot and the idle orifice where it is discharged into the manifold. The idle orifice is controlled by the idle mixture screw.