water temp question- 2005 50 HP ELPTO

[thomas15]

I have a question:

When I have the outboard hooked up to muffs, should the water coming out of the pisser be warm? What comes out is not warm at all. I'm going to replace the water pump impeller and thought perhaps I should consider replacing the thermostat as well. May I have your opinions please?

Thanks in advance.

My motor
50 HP Mercury
2005 ELPTO
S/N 1B018403

 

[Texasmark]

That engine probably has a 143F stat. Number is stamped on the bottom of the pellet. It controls engine temp below about 2500 rpm and maybe at all rpms on that size engine. The larger engines have a bypass valve that opens at that rpm to allow for additional cooling at the higher heat loads higher rpms generate.

Pull your cowl and look at your pee tube. Follow it back to the engine. If it connects to a large flat plate on the Port (left facing forward) side of the engine that's your exhaust manifold water jacket. That circuit gets cooling water directly from the pump and is not controlled by the stat. So, if you are idling on muffs, it will be cool, not hot like your domestic hot water heater in the house puts out.

With that said, it's never a bad idea to change stats. I had 2 fail over the years. First had no over temp alarm and cost me an engine block overhaul. Second was a recent engine with an alarm and it saved the costly repairs.

Mark

 

[thomas15]

Thanks for taking the time to share this information. I guess I will replace the thermostat and see where that takes me. I also will pay better attention to the temp when the outboard is running under load.