Manifold Gasket Replacement
 

I am getting ready to replace both exhaust manifold gaskets on my 5.0 liter Mercruiser. I am not planning on removing the risers to do the replacement. Are there any secrets or tricks I should know about before I tackle this project?
I saw something on You Tube about making sure I drain the water from something before I unbolt the manifold or water could get inside the engine. Can someone tell me what I need to drain water out of, if anything?
Thanks

Re: Manifold Gasket Replacement
 

Drain engine via the blue twist plug for the cooling system(not sure where on that year) , should be fairly easy to spot. Might want to pull hose from front of manifolds just to be safe.
Easy job , I suggest using a lube of sorts on the rubber boots that go to the Y pipe when reinstalling manifold. :)

Re: Manifold Gasket Replacement
 

In the bottom front of the engine you have a blue plastic screw, open it and the engine will drain, you should also open the one on the thermostat hosing to get air into the system.

Why do you have to change the gaskets?