What type of leak protection is there between the power head and the lower unit in regards to the exhaust. Is it a gasket like those used with exhaust header gaskets on automotive engines? Reason I ask, I believe I've got an exhaust leak once my engine has been run at WOT for over 10 minutes. AFter the engine heats up, I hear noise coming from the bottom of the powerhead. It seems like the engine needs to be heated sufficiently, after idling the engine for a few minutes, the sound goes away. It isn't a constant sound, but is cyclic like an exhaust leak would sound. I'm wanting to know what to look for in determining if I need to pull the powerhead to fix it. It is more of a nuisance sound. Thanks.<br /><br />edit: 1996 Mariner 115
