gas:oil ratio for 1949 5 hp sea king 2-cycle twin outboard

[Julie303]

Does anyone know what the proper gasil mixture should be for a 1949 5-HP Sea King 2-cycle outboard motor?

[SVDistantStar]

50:1 will work just fine in it.

[ebs001]

All older motors that I can recall from the 50's, the recommended ratio was 25:1

[Rockter]

Not 50:1 for a 1949 motor. Not so.

Very few modern motors get by on that. I know of only one... the MZ 301 motorcycle.

Run rich for an old motor... 25:1 or even 20:1.... it'll smoke like crazy though.

The problem is that the old ball and roller bearings were quite sloppy, and needed alot of oil to float them. Quality is no substitute for quantity in those old bearings.

[capngregg]

I got the information below from another on-line forum but it is what I run in my 1945 Gale Manufacturing motor. They have flat bearings in the mains and rods. Gale Mfg. / Sea King sold by Montgomery Wards.

You can mix modern unleaded gas 24:1 with TCW3 rated 2 cycle marine oil and you should be fine. (This was for a 1951 version of the same motor)

Manuals are hard to come by but they're out there. Same with the parts.

Good Luck! That's a nice little motor.

[SVDistantStar]

I would have figured 50:1 would work fine. We use 50:1 in a 50's Evinrude 18hp motor that we have.

[Hartley18]

Capngregg mentions "modern unleaded gas" - a similar question I was meaning to ask is:

We have a choice of 91-, 95- and 98-octane unleaded depending upon how empty you want your pocket when you pay up at the till..

Is there any difference when mixed for a 2-stroke??

[Lancer28]

That motor won't benefit from higher octane; stick to the minimums.

[Hartley18]

Thanks - I assume that holds true for modern-ish Johnsons also.

BTW: Did you manage to locate any electrical data on my 7.5hp? I'm still at a loss to know what to do there...

Thanks in advance,
Cameron