Water temp

[Firefly54]

Once engine is warm at 195 it builds to to 280 then bounces back down to 195, it continues this cycle no matter what RPM. any ideas why it would not hold a steady water temp? has new thermostat.

 

[RicardoMarine]

I doubt that your engine is reaching 280 degrees. You very likely have a temperature guage problem.

Re-create the temperature climb, and aim an infrared heat sensing intrument towwards the engine near where the thermostat housing is located.
This should give you a more accurate reading.

 

[Firefly54]

I doubt that your engine is reaching 280 degrees. You very likely have a temperature guage problem.

Re-create the temperature climb, and aim an infrared heat sensing intrument towwards the engine near where the thermostat housing is located.
This should give you a more accurate reading.

Good idea, thanks for the input.