not that old Johnson motor

[jcrigan]

I just picked up a 6hp Johnson 6R70 outboard cheap that was missing the gearbox. I thought I had one but it was for an earlier 5.5hp model. What years will interchange with the 1970 models? Thanks, John C.

[Mumbles]

’56 to ’79 gearcases from the 5.5, 7.5 and 6 horse motors will bolt right up to your motor but the shift rod in the ’64 and earlier ones will have to be replaced with a ’65 and later short one to hook up to your upper shift rod. The ’54 and ’55 gearcases will work to but they will need a ’56 to ’65 driveshaft installed to as the earlier ones were a slightly different length.

[jcrigan]

The one i have looks like it will work but like you said, the shift rod has to be replaced. I also noticed that the drive shaft on this earlier model has a larger diameter. I wonder if this can be changed. It is probably from a larger motor than the 5.5.

[fleetwin]

Are you sure the gearcase is from a 5.5hp? Perhaps it is from a late 50s 10hp, the gearcase housings were the same, but the driveshaft diameter was larger. Post a picture of the gearcase if you are unsure of what you have.

[jcrigan]

I measured the drive shaft. The main part measures 0.550 and then it is stepped down to 0.50.

[fleetwin]

If the driveshaft is stepped down/thinner at the upper splines, I’m betting the gearcase is for a 1958-63 10hp.

[Mumbles]

If the driveshaft looks shorter than normal, it’s from a 9.5.

[jcrigan]

Thanks all. That gives me more options. And now i know more about what this one goes to. It was originaly holiday bronze.

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