The arrows that say "cleaned" in green are where the main jet and pilot jet go. The other "cleaned" is where the float needle goes. The ? is a brass plug that prevents tampering to the idle mixture screw. Find a sheet metal screw, drywall screw, or something similar and drill a small hole in brass plug, screw in screw and pop out brass plug. Be careful not to hit the screw underneath with the drill or it may screw it in so tight it will damage it. That screw needs to come out when doing a carb clean. There is also a spring and O-ring under the screw, maybe a washer, I don't remember, don't lose them.