Temperature Question

[HPLou]

1989 Mercruiser 4.3LX S/N OC534197
When I navigate the Temp Gauge reads 120-130 degrees.
I was winterizing the motor last week and with the Muff The temp Gauge was reading 160 witch is the right Temp for my engine.
What can cause the Temp to be different on Muffs & on the water when navigating?
Thanks.

 

[300sflyer]

Your thermostat could be stuck open. Your garden hose has limited water flow, which is likely why it runs hotter than when you have the boat in the water.

 

[Starcraft5834]

lack of water........I mean "enough water".. if you dont have one now, get a pair of muffs that feed water on both sides.......

 

[HPLou]

I will remove the thermostat and check it to see if it functions OK and see if it is stuck on Open position.
I will put it in a pot and heat the water. I will see at what temp it opens.
Thanks for the hint.

 

[jayhanig]

A new thermostat is what? $8? Just replace it and be done with it. You're going to have to replace the gasket anyway.

 

[achris]

A new thermostat is what? $8? Just replace it and be done with it. You're going to have to replace the gasket anyway.

No,a proper marine thermostat (and yes there is a difference) is about $35.

 

[HPLou]

Price is not an issue (it's not $200). I will change it with the marine type.
Thanks