How often do people change their oil. I have an 1993 OMC (ford) King
Cobra I/O. I have been changing the oil about every 100 hours. Just
read somewhere that 300 hours is OK? What weight would you use up in
New England for this time of the year. I generally will pull my boat
out for the season in late December.


I change engine oil and filter every 50 hours and lower unit gear lube every
100 hours. I use Mercruiser's 25W-40 4 cycle marine engine oil for both of
the propulsion engines and the genset, and their High Performance Gear Lube
for the lower units.

Thanks everyone for your input. I use my boat quite a bit and usually
change it every 100 hours which means at least 3 or 4 time a season
here in the North. From your responces, I will change that to more
like every 50 hours. I have a mechanic do the lower end each season as
I do not have a trailer and can not take it out of the water as often
as I would like.