Re: 5.5 Johnson age and oil mix ?
OMC introduced their own brand of oil in 1964 and at that time they recommended 50:1 using their oil only.
I'm not 100% sure, but I think your 5.5 was originally 16:1 or 1/2 pint per gallon. At any rate, I think you would be perfectly safe using 24:1 with today's TC-W3 oil. If it tears up, don't come blaming me-it was going to tear up anyway. If you object to all the smoke, try full synthetic TC-W3 outboard oil for a lot less smoke. I get mine at Wal-Mart (Castrol).