Temp gauge pegged with key off

[nextboat1]

Hello, i noticed that after running my boat my temp gauge will go up to 220 sometimes after i shut the key off. Sometimes it returns to 0. If I turn the ignition back on the temp guage will lower. My boat always runs in the 170 range wether at idle or on plane. Is it normal for a temp gauge to do this? Is it something i should worry about?

 

[Silvertip]

Some gauges "float" when the key is turned off. Not an issue as long as it reads correctly when the engine is running.

 

[keith2k455]

Ditto...as long as its correct when running

 

[achris]

All Merc gauges are 'unsprung', which means they don't necessarily return to zero when powered off. I've seen tachos indicating 4000 revs with the key off. As soon as the key is on, everything returns to where it should be...

Chris.......