I found my oil change kit. I've been using Mobile 1 0W 20 since 2001. 6 seasons in the water with that oil only changed twice.

Important note: I sail on an inland lake. I doubt if I've had the engine running more than 30 minutes at a time at anything over an idle that whole time.

I'm going to try to start it this afternoon. Wish me luck, it's been almost 4 years! I'll check to see what oil filter I have on it.