i cant find it on johson parts catalog ( i assume cause it shows post '68 motors and mine is different?) but seems to be just part of the auto choke.
Try the link below for the original OMC Parts Catalog for your motor. Make sure you click on the correct model number because there are differences. Good luck!
http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1966&hp=80