3.0 OMC Engine Oil Type

[tallguy63]

Stupid but necessary question..What type of oil should I put in my '89 Bayliner Capri OMC/Cobra 3.0L. The seloc manual only mentions that SAE 30W should be used. Should I use 5 W or 10 W - 30 oil? Also what viscosity gear oil should the out drive take? Thanks

[Don S]

Here is what Mercruser recommends, it's almost identical to Volvo's and since OMC hasn't existed for 10 years, they have nothing new.
But that engine is still used today by Merc and Volvo.
Basically, anything will work if you change it every 100hrs or yearly as the manual suggests.