What is the black plug for, starboard side Johnson 60hp 4 stroke

[danford1]

I have a 2005 Johnson 60hp 4 stroke outboard. There is a black plug on the mid section of the starboard side. What is it for? I know the oil drain is on the port side... There is also another plug on the port side that isn't the oil drain plug, what is it that for? I can't figure out how to post pictures here, sorry.
Danford1

[boats.net]

There is a oil drain plug and a fresh water flush plug.

[danford1]

My 60 hp has three plugs on it. One on the port side is the oil drain, One on the port side, aft, I don't know the purpose. One on the starboard side, I don't know either. I was hoping the shop manual would help but it doesn't. I thought this Johnson forum would have knowledgeable people in it.
The starboard side plug appears to line up with a plug in the exhaust manifold. What would it be for?