More fine tuning can be done by gaining access to the pilot fuel mixture screw. This screw is hidden underneath a blind plug, identified in the photo with an arrow. Adjusting this screw is considered tampering with an emissions control device in some locations, so proceed at your own risk.
SAFETY FIRST: Protective gloves and eyewear are recommended at this point.
Remove the air mixture screw plug from the bottom of the carburetor using the following procedures.
Use a 1/8” drill bit, with a stopper 4 mm from the end of the bit, to drill out the plug covering the pilot screw. A piece of hose around the drill bit makes a good stopper. Carefully drill through the brass plug.
Thread a self-tapping screw into the brass plug.
Remove the plug by pulling it out with a pair of pliers.
NOTE: Before removing the pilot jet, count the turns it takes you to lightly bottom the screw out into the carburetor, this will be your initial setting when re-assembling.
Make sure to remove the following parts: screw, spring, washer and rubber stopper washer.