My old 1949 Evinrude 3.3 hp. sport twin calls for 40 wt. engine oil in the gas. Back in 1949 I’m sure that worked. But today with all the new oils for 2 cycle motors, what should I be mixing, and how much to one gallon? 24:1? 40:1? 50:1??
I have a 54 3.3hp, it is not to much different than you 49. I run TCW3 synthetic oil at 20 to one and it does fine. Those automotive oil that they used to recommend made carbon in the exhaust build up like crazy! Synthetic oils are better for the water we play in and we should all remember that. Big controversy on this website about oil and the ratio. Your old motor has no ball bearings of any type. The thought is more oil is better. My humble opinion is, extra oil just goes out the exhaust.
16 to 1 TCW3 oil. for none bearing motors.
So not exactly an oil question but related, gasoline. I recently purchased a Johnson 1940 HS-15 and had an old outboard mechanic tell me I will need to go to the air port to buy gas. Could someone comment on what octane to run in this motor.
Lots of us use regular 87 octane unleaded pump gas. Others insist on Ethanol-free gas. Let the debate rage on.
Airplane’s have high compression engines.
10 to one and higher needing high octane fuel.
In 1940 compression ratios were around
5 or 6 to one. It wont hurt anything but your
wallet. My motors run from 1920 to1953 and
I buy what ever they have where ever I’m
at. With or without Ethanol.
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