Fuel, which passes through the metering rod jet, is metered to the low-speed circuit by the low-speed jet tube. The fuel passes through two orifices in the tube, one at the bottom and another in the side (auxiliary jet). The second orifice is at a point about three-quarters of an inch from the end of the low-speed jet tube, inside the bleeder tube. The fuel passes through the low-speed jet tube, the upper end of which is pressed into the air horn, across the passage in the air horn, where it is mixed with air entering from the bypass through the economizer, and down through the passage cast into the main body flange, and then down through the passage in the throttle body. Fuel is discharged from the idle port and idle adjustment screw hole. Note that the main body gasket forms one side of the cross passage in the main body. It is important that no air be allowed to leak in at this point.