Mercury 200HP Screw Hole on Block

[Themanofsteel]

I have a Mercury 200HP Outboard Blackmax Offshore 1991. There is a threaded hole at the base of the block. See picture. Exhaust comes out of here. What’s suppose to be here??

 

[Faztbullet]

There was a pressure fitting that mounts in threaded hole to supply air pressure to boat side oil tank. Plug it off as it can cause cylinder to run lean and a fire under cowling.

 

[Themanofsteel]

Ok. I disconnected the oil injector and just premix. This isn’t needed then?

 

[Faztbullet]

No it has to have a plug if injection is removed.. that is raw fuel/air mix you see expelled from hole....very explosive.

 

[Themanofsteel]

Ok. Thanks!

 

[Themanofsteel]

I have another question. This threaded hole on the head is also opened. The other head has a value on it with a hose. Should something be here or can it remain unused?

 

[Faztbullet]

Remains empty