Mr Maine

Change it before, during, and after every run. Then you rule out any contaminents!!
Seriously, some people put 15 hours on a boat in a summer, does it really matter? You could argue heating and cooling all winter can introduce condensation too.
Definetly not against it especially if its been run hard and needs to be changed but dont over think it.

class6

Oil in my lawn mower has to be 10 years old Should I start thinking about changing it

87MirageIntruder

I've always changed it in the spring but it sounds like I have been doing it wrong. Glad I read this thread!

picklenjim

By products of combustion and heat cycles makes oil become acetic to a point it actually becomes corrosive. The older and nastier the oil is the more acetic it becomes. Sitting long periods is when it does it's damage. I leave the drain plug open on my engine all winter. Inside storage.

SB

I'd like to see evidence , or how about even a made up story , of an engine that was seriously damaged from changing oil in spring...or even worse, received an oil change every two years.

scarabman

Funny thing is, I actually know a guy with an older SeaRay, late 70s early 80s, not really sure as I dont know chit about SeaRays. Boat has twin small block Mercs. He only uses the boat maybe 15-20 hrs a yr or so, and as such feels the need to change the oil every 5 or so yrs, whether it needs it or not. He has like 600 hrs or something with no issues. I only found this out because one day at a mutual friends house, we were talking maintenance on my boat, and he asked if he could have my 20 hr old Mobil 1 15-50 drain oil to use in his boat, as he told me I was wasting my money with what I did!

F-2 Speedy

All depends on the yr, make and model.............if its a black engine ? they will run 12-1500 hrs without top end refresh....with the same oil

Knot 4 Me

Oil is supposed to hold dirt and other contaminants in suspension so...

minxguy

If you use non dertergent oil, that will never happen.

Ken

Knot 4 Me

20W50 Tide!