'55 Johnson 10hp prop

I know I could just test this, but....

I have ran my motor with the original prop since I have had it. Is there any advantage to running the newer prop?

original


newer

The prop you have is a weedless design. I have several of these because no-one likes them. They just sit there on the shelf collecting dust. There is a large benefit from switching to a regular type blade. The one in the second picture will not work for your engine. 10HP Johnsons up to 1957 used the larger lower unit for the 15-18hp. This means the propshaft is bigger. The props for the 15-18-20-25hp will fit but they are too big for the 10hp output. OMC made a regular prop for these but it's hard to find in good condition. It really adds to your efficiency. Michigan-Wheel made some excellent brass props for these particular engines. That's what I run on my QD-16. It pulls a solid 21mph with me and my wife in a 12ft rowboat.

I can gather some pictures and part numbers if you would like me to.

Curses, I totally gapped about the larger lower unit for this motor having a larger shaft.

What are the chances of boring the "modern" prop ID to match the larger shaft? Would it be possible or do you think the chance of imbalance too great, or perhaps some other reason this is not feasible?

I will search around for the Michigan Wheel prop you mentioned. At your leisure and if you get the chance I would definitely take part numbers.

I gap all the time. Eventually I'm gonna string these senior moments together into a lifestyle...

I'll get some info together next day or two.