Johnson K-50 Prop

[Buccaneer]

Put the last piece on the project motor today, that
being the prop. It had numbers ………
9-1/2 x 9-1/2
27D57

Just curious……… did Johnson put numbers on the factory props
circa 1932, or would I have a replacement of some kind?

27D57 isn’t a number that shows up in the Michigan Wheel database
on this site.

Tomorrow, if all the stars align, I’m going to try to fire it up for
the first time. If it actually runs, I’ll probably pull the tank
back off, see if I can buff it to a better shine, and put a decal
on it.

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Prepare to be boarded!

[Mumbles]

Is that an 8:1 motor?

[oldelto]

27D57 is Johnson’s part number. 9 1/2 x 7 3/4 3 blade Lynite prop

[Buccaneer]

quote Mumbles:

Is that an 8:1 motor?

If I remember correctly, I think it takes 3/4 pint per gallon. I had on
a paper in the garage that is an 11:1 ratio. I can’t back up my memory.
Anyone have the correct mix for sure?

Prepare to be boarded!

[Buccaneer]

quote oldelto:

27D57 is Johnson’s part number. 9 1/2 x 7 3/4 3 blade Lynite prop

I guess Johnson did use numbers on their props then.
I have some old "Evinrude" prop data scrounged from this
club. Is there Johnson prop data I missed?
Thanks!

Prepare to be boarded!

[Mumbles]

Here you go.

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[Buccaneer]

Thanks Mumbles!
I see they don’t show the "D" in the middle of the part number,
but otherwise, a match.

Prepare to be boarded!

[squierka39]

Yes they did mark the Johnson props. I think the 9 1/2 x 9 1/2 is off a slightly later motor, or yours being a later K50 might have different gears than the early ones, as noted above the pitch is lower for the K50, all the later ones got the 9.5 pitch.
I’m not sure the differences but the K50 has a different Lower unit then the K65 thru K 80.
Your motor looks great by the way.

Looking at the chart above there are 2 sizes for the K50, probably when they changed things a bit.

[Author]

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