Assuming that you have closely inspected and cleaned all the components, here are some instructions on how to assemble the upper casting.
Upper Carburetor Casting Assembly
- Insert throttle shaft into casting and attach throttle plate to the shaft with 2 oval 5/40 screws. Turn Idle RPM adjusting screw on throttle arm so that throttle plate remains slightly open when it is closed.
- Position cap and spring onto idle air mixture screw and then screw it into the casting. Initial setting of the idle air mixture screw should be 1-1/2 turns from full clockwise.
- Screw in Filter Strainer, with a gasket washer, using a 5/8" wrench.
- Screw in Float Valve with appropriate gasket washer thickness.
- Attach Float with Float Hinge Pin.
- Screw in Idle Jet, with no gasket washer as it is designed for a taper fit. Use Drilled Out 9/32 Nut Driver.
- Attach Upper Casting Assembly to Lower Casting Assembly, with Main Bolt and lock washer, using appropriate 1/2 or 9/16" wrench.