Missing Idle Screw!

Does anyone know what size screw the carb idle screw is? (48cc Starfire) Mine was backed out pretty far on the ride home and...gone. Now I'm running but she dies with every clutch engagement. Can anyone help? I have a Fastenal down the street so I bet I can fix it today if I can figure the size out! Thanks for all the help everyone! Chips

I made it home with an 8/32 x 1/2 as an inpromptu idle screw. I will grab the correct one tomorrow. I just file it to a rounded point, correct? (I've never seen the end of it before) Thanks guys!