1956 Johnson 7.5 need even more help

[aaind]

Well the last post was about pressure and not making it ,got past all that found that top jug was dead rod was broke ,was running and not to bad but.
So now I need a power head ,will a 5.5 work on a 7.5 and vise versa ,I have a good hood for a 5.5
Thanks

 

[steelespike]

Re: 1956 Johnson 7.5 need even more help

There is a significant difference in displacement The 5.5 is 8.84 cu.inches, the 7.5 is 12 something.
They don't share bore or stroke. I think they did share a gear case at some point.
I'm sure someone will be along with more detailed info.

 

[Chinewalker]

Re: 1956 Johnson 7.5 need even more help

Only way it would work is if you have a COMPLETE 5.5 powerhead, including the hood, as the powerheads are quite different. They share ignition components and, if the same year, they share recoils, but that's about it. Carb, flywheel, crankcase & block are all different... Lower units are the same, although the 5.5s have a restrictor in the water tube to help them run a little warmer...

 

[aaind]

Re: 1956 Johnson 7.5 need even more help

Well hmmm ,think trying to find a 7.5 would be best then ,which is really what I want
Thanks again guys

 

[HighTrim]

Re: 1956 Johnson 7.5 need even more help

What is the condition of the bore? I likely have a good rod if you need one.