mercury outboard saltwater series pisses fine but water is extremly hot

[giseppe69]

I have a 2001 mercury 150 saltwater series. When engine is running just after few minutes in water the water coming out is hot . steady stream , no hiccups no steam. but if put hand under it can maybe keep hand there for about 3seconds. Any idea how hot should be or what could be causing this?

 

[wired247]

Its supposed to be hot. That water is coming off the thermostats that are opened at that point

 

[Texasmark]

Some Mercs use the 143F stat, I know of a 90 and 150 that do. That means that when the engine is below the speed where the poppet, bypass valve opens from water pressure at around 2500 rpms on some engines like mine, the stat shuts off circulating water through the block proper until it starts to open at that temp. Takes 10 or so more degrees to open fully.

140F is the temperature of most US domestic hot water heaters when the thermostat is set to the N position. Sounds like that's about where you are.

Mark