Changing Primary Metering Jets
Remove airhorn casting from main body casting. Remove airhorn/bowl cover gasket. Note positioning of needle and seat attachment clip to the float, you will want to re-position the needle clip in the same manner when you re-install the float assembly. Remove the primary power piston assembly. Remove the float assembly. Using a flat blade screwdriver that’s fits snugly in the primary jet slot, remove the primary metering jets by un-screwing counter-clockwise. Install the new Primary metering jets, being sure not to cross thread the jets. Tighten jets. Install the float, then install the primary power piston assembly. There should be a spring at the bottom of the power piston bore, ensure that the spring is in place. Lower the power valve in the bore and carefully guide the primary metering rods into the primary jets. This procedure can be tricky and may take a few tries. Once primary metering rods are positioned in the main jets and the power piston is in the down position, press the plastic retainer into the top of the power piston bore to retain the power valve assembly. Press down on the power valve assembly to verify that the valve travels up and down smoothly. Install airhorn gasket and carefully place airhorn on carburetor ensuring that all tubes are in their respective holes. Install airhorn screws and tighten evenly using reccomended pattern.