Re: 1966 Evinrude Lightwin 3 hp oil mix

[frankr]

I seem to remember that the 1964 change to 50:1 was ONLY if Johnson (or Evinrude) oil was used. Otherwise, the old spec was still in place. So now the question becomes what was different about the oil? The formula was a well guarded secret, but I did hear from a factory engineer that it contained some synthetic oil. One thing I am very confident of is that it was indeed something special. I’d seen that proved over and over again in engines that had been run hot.

So..is today’s TC-W3 oil the same as the old J/E TCW oil? I seriously doubt it. I suspect that old TCW oil had some automotive detergents in it. Technology has come a long way since then, and motors do not carbon up anywhere near as badly as they used to. No doubt getting rid of the lead also has something to do with that.