I have a 1973 evinrude outboard,model 5373 triump 65 hp.I have not had a chance to get a manual yet,but there are three holes in the front of the engine that have small circular covers on them.I dont know if they are carburetor/choke covers,or air intakes.I lost one of the covers and without it being covered my boat won't go but 5mph.Can someone help me with this please?