Size of pickup screw?????

[pittspilot]

Does anyone know what the size of the throttle pickup screw on a Mercury 20hp, 1973, Serial 3758866 is. My motor seems to have misplaced this screw.<br /><br />It would be a great help as it would save me having to remove the throttle assembly and then have to readjust it. <br /><br />Thanks in advance