andrew - I think you're referring to the exhaust manifold. Items 1 / 22 in the diagram:
Agreed about the danger of sparks from motor brushes. Fortunately, I don't use gas for cooking inside the boat. I use electric when at the dock hooked to shore power, or the propane barbeque outside on the stern rail.
(I do need to move my propane tank outside the cockpit storage locker though - it could potentially leak and sink into the bilge.)
And I do have a good bilge vent blower available for motor cooling should I need it.