Take lots of pictures before you start and as you dissassemble the carburetor. Schematics are generic and it’s unlikely you’ll find one that shows your exact carburetor.
Clean the carburetor well by soaking in a sonic bath, Berrymans parts cleaner, or Simple Green (follow manufacturer instructions)
Rinse with hot water and dry well
Polish the pump bore with corcus cloth and oil before reinstalling pump
Romove screws which hold upper body and lower body
Lift off the upper body and pump assembly
Unscrew float hinge pin and lift out float and float needle
Remove main jet inlet valve, pump, check valve, and economizer valve assembly
Remove the main discharge nozzle
Remove vent tube
Remove step-up piston plug, piston and spring
Remove idle passage tube
Use compressed air to clean all tubes and jets. Never use a wire or drill. Remove all foreign material which may have accumulated on economizer piston or pump piston and make certain they operate freely
Assemble by reversing the foregoing operations. The pin end of the economizer piston rod should be insterted in the economizer valve assembly