I pulled my manifolds and risors (log style 228 mercruiser) apart and was reasembling when i noticed that the hoses from the thermostat housing cover to the risors (where it cools the exhaust and goes overboard) the hose fitting in the risors is sealed off not rust but like a closed off fitting is that the way it is suppose to be??? It seems to me that if that is sealed then no water will go overboard is that correct? I am doing this because the boat is overheating at high rpm's could that be why? I have a new water pump new impeller and inflow is great. HELP PLEASE 