Chip S
Active Member
- Jun 17, 2019
- 432
- Boat Info
- 1993 Sea Ray 200 Overnighter
- Engines
- 2023 Mercury 150 hp Four Stroke Outboard
I just had the water pump impeller, thermostats, and poppet valve replaced on my 1993 Mercury 150 hp Black Max outboard. The mechanic said the old thermostats and the old poppet valve were constantly open. This might explain why my engine temperature would be 130 degrees when I was idling off plane and 170 degrees when I was on plane.
Looking at the attached water flow path I can't seem to understand how the system works. It seems to me that when the thermostats open the engine gets less cooling water and the temperature should go up, not down. Can someone explain how the thermostats opening increases the cooling of the engine?
I understand that the poppet valve is used to relieve excess water pressure at higher rpms. If the poppet valve is open at low rpms wouldn't this result in higher temperatures since the engine would not be getting enough water? Any insight how this system works would be greatly appreciated.
I'm picking my boat up on Saturday and plan on test driving it. Hopefully with the new water pump impeller, thermostats, and poppet valve the temperature will stay at a constant 150 degrees or so. We'll see.
Looking at the attached water flow path I can't seem to understand how the system works. It seems to me that when the thermostats open the engine gets less cooling water and the temperature should go up, not down. Can someone explain how the thermostats opening increases the cooling of the engine?
I understand that the poppet valve is used to relieve excess water pressure at higher rpms. If the poppet valve is open at low rpms wouldn't this result in higher temperatures since the engine would not be getting enough water? Any insight how this system works would be greatly appreciated.
I'm picking my boat up on Saturday and plan on test driving it. Hopefully with the new water pump impeller, thermostats, and poppet valve the temperature will stay at a constant 150 degrees or so. We'll see.