The solenoid is connected directly to the bottom Carb and then there should be two rods connecting the other two carbs to the bottom one as per the parts diagram. OMC did switch over to a priming system later on is it possible you have a later model block or intake system? The first link is for your 80 and shows the choke the second link is for a 85 and shows the priming system.
http://www.marineengine.com/parts/j...CSA&manufacturer=Evinrude?ion=Intake+Manifold
http://www.marineengine.com/parts/j...COS&manufacturer=Evinrude?ion=Intake+Manifold
The choke plates should be open all the time unless the choke is activated. Activating the choke by pushing in the key closes the plates restricting airflow into the carbs which will enrich the fuel air mixture thus making the engine is easier to start. You have a manual lever on the solenoid if you flip that it should open the chokes up.