Place the carburetor on a clean work surface.
Remove the choke return spring.
Use an Allen wrench to remove the float bowl drain plug and drain fuel from the float bowl into your fuel-safe container.
Replace the float bowl drain plug gasket.
Lubricate the float bowl drain plug gasket with petroleum jelly.
Reinstall the float bowl drain plug.
Remove the float bowl screws and pull the float bowl off.
Remove the float bowl gasket.
Pull out the float pin and remove the float and needle valve.
Pry out the main jet.
Remove the retainer and O-ring from the outlet port.
Remove the air cleaner gasket from the carburetor.
Clean all carburetor parts using carburetor cleaner.
Spray carburetor cleaner through all openings in the carburetor.
Use small-gauge wire to clean all jet openings.
Carefully blow canned air or compressed air through all openings to remove residue.
Wipe down all parts with the shop rag.
Install the new O-ring in the outlet port and reinstall the retainer.
Replace the O-ring at the bottom of the main jet.
Reinstall the main jet.
Insert the new needle valve and new float pin in the float and reinstall the float on the float bracket.
Carefully install the float bowl gasket by pushing it into the channel on one side of the bowl and holding it with your finger. Stretch the gasket beyond the lip of the bowl and work it into the channel without rolling the gasket over.
Lightly lubricate the gasket using petroleum jelly.
Reinstall the float bowl and secure it with the mounting screws.
Install the new choke return spring.
Warning: Rolling the float bowl gasket into the lip channel can cause fuel to leak through the gap between the float bowl and carburetor body.