Hi, Juice.<br /><br />OMC recommended 24:1 for all engines prior to 1965.<br /><br />However, some of the larger engines had ball, roller and/or needle bearings and many believe they can use 50:1. The 75 V4 is one of those.<br /><br />I would stick with the factory spec, but use your own judgement on that.<br /><br />Good luck.
The detrmining factor on what ratio to use on outboards was/is determined by the oil, not by the outboard guts. My 1968 18 hp Evinrude was supposed to run at 20:1 new. I ran it 50:1 last three years I used it.
