What is the Expansion Chamber on my M2/Opti?

[Faken]

Hey guys,

I had to order a new gasket for the expansion chamber on my 2001 Utopia 185, as in the area where the Optimax engine sits on top of the M2 jet drive unit. Seeing as there is a gasket in there, that would mean there is some kind of fluid/pressure in that area, can someone tell me what it is and/or what is happening in that chamber that requires a seal?

Thanks
Dan

 

[Dr Honda]

It's the big round thing, aft of the engine... and has the 2 large rubber hoses that go to the water boxes. (mufflers)

There is an outer water jacket that water is fed though, to keep it cool. If it leaks... it will over heat, and/or dump water into the boat.

 

[Faken]

Thanks Tony! I did know where it was, I was just curious about what was happening inside that area that required a seal, thank you as always for the info!

Dan