Reply To: ’57 Evinrude 7.5 fleetwin fuel mix

[kerry]

Plain bearing motors need QUANTITY of oil to maintain clearances without burning up from metal to metal contact. Remember, we are talking about 1950’s era manufacturing and mass production. It was hard to maintain a few thousandths tolerance in mass production back then, whereas nowadays a ten thousandth is possible with CNC machinery. People who say modern oils are better forget that those oils were made for modern motors, not 1950’s motors. Better, yes, but only in the ratio the manufacturer recommends. Run a good oil at 16:1 and your motor should be happy for another 60+ years.

If you have too many, AND not enough, you're a collector.