Help ID these ports on '73 Mercury 20 hp

[seanymphmike]

Can any one tell me what these ports are on the back of my '73 Mercury outboard. As I was walking up to the boat this evening I saw a carpenter bee carrying a piece of cut up leaf up into one of the openings. I sprayed a tiny bit of OFF into the opening to dissuade the bee from coming back. I don't know how much nest building the bee had done, so what are these ports and do I have to be concerned?

 

[GA_Boater]

Re: Help ID these ports on '73 Mercury 20 hp

Those are the idle relief ports that allow the exhaust to get out of the motor when it idling in the water. Since that leads through to the exhaust and into the cylinder, I would put the motor in a barrel or in the water and fire it up to flush her. First look in there to make sure they aren't packed with mud or in your case any leaf chunks.

 

[seanymphmike]

Re: Help ID these ports on '73 Mercury 20 hp

Thanks, Ga Boater. I thought that they were part of the exhaust system but I wanted to be sure starting the engine wouldn't be sucking any of that junk into the engine.