Originally Posted by broncotw
OK! I just replaced the oil in my 93 last April (4/2013) and used Mobile One (synthetic).... I only put appx. 25 hours on the boat this past season.... I winterized the boat in November (11/2013) and left the oil in the block.... When I go to un-winterize the boat should I change the oil?
Yes. Combustion contaminants are in the oil. Even though there are additives to buffer the metal in the engine, the oil and additives will oxidize over time.
Plus oil is cheap compared to an engine.... don't forget a new filter..