Cooling system for Marine Power 496 & Dominator Pump
I want to make sure I understand my cooling system. It appears to be a closed system. Marine Power 496 Vortec 8100 with Dominator pump. I do regular maintenance on this every year and have never done anything to the cooling system. Runs 150* all the time. Now that's this is 9 years old with 138 hours if the system is closed I want to change the fluid. I see a water pump. At the jet where the pic shows the braided line this area is warm to touch when I pull the boat out of the water. How exactly does this system work? Where do I drain the system from and what do I replace it with?
Just a thought Jeff but I don't see a Heat exchanger ? ( large round cylinder sets atop the engine similar to a radiator) common to a true "closed marine system" . I suspect what you pictured is a marine cooling system uses a type of controlled raw water cooling (similar to other free flowing jet systems) , the water to the engine is supplied from the "lake" by the jet drive (and then the water recirculates (dwells) in the engine for a brief time) with a belt driven automotive style recirculating water pump and special T-sat/plumbing arrangement, being constantly replenished from the bottom of the engine with cooler water . Assuming you do have that type system the cooling water circulates and "dwells" for a short time in the engine with flow being controlled @ a given temperature by the special thermostat arrangement . Theres little to no maintenance to that type system beyond hoses belts and perhaps an occasional Thermostat Tom
ps likely is the fitting feels hot as there is no provision to prevent back flow from the engine system when you pull the boat and the hot engine water flows back into the jet