Mercruiser 165 HP running warm

[Salty Cat]

I just bought a 1972 Fabuglas 17 foot with a 165 HP Mercruiser I/O. As long as the speed of the boat stays around 20 mph the temp guage runs in the green, but when the speed gets around 30 mph the temp guage goes into the red. A new water pump in the propeller area was just installed. Any ideas of what we should look for? Thanks for any help.<br />Salty Cat

 

[The Marine Doctor]

Re: Mercruiser 165 HP running warm

Possible waterways plugged. 1 fin backward on impeller. Circulation pump on engine.<br /><br />TMD