I just bought a 1974 Hondo. 18'. It has a chevy 454 in it and runs nicson water cooled headers. It's my first jet boat so I'm not sure what the engine temperature should be? A hose comes up out of the jet and runs into the front of the motor through a valve that seems to control the engine temperature depending on how much you turn it in or out. Seems like it adjusts the flow. The colder the water the less flow you need? Anyways, I'm running it at utah lake. water temperature is about 55 degrees. Air temperature is approx 75 degrees. Also, does the water after it has run through the motor shoot out the headers? It looks like a small line returns to the back of the boat and runs out next to the bilge hole. It drizzles hot water when the boat is running. Any help?