2006 mpi motor wont warm up

[hudman]

i have a 2006 mercruiser 383mpi motor, 288 hours on it, freshwater. recently the temp will not go to the operating temperature, 156-160 , it starts at 87 and only warms to 111-115,, is the thermostat stuck open? is this common?

 

[Bondo]

Re: 2006 mpi motor wont warm up

is the thermostat stuck open? is this common?

I don't know how Common it is,......
But,....
I'd start by looking there........