Johnson QD rod/piston swap

[shoestringmariner]

Hey folks, Another thread opened my eyes to the vast size differences in the rod & pin sizes in the 50’s through early 60’s QD’s.

The thread states that you can use the 58 and down rods with earlier QD’s, but did I hear in another thread that the 61-63 rods will work as long as I use the 61-63 pistons?

I have a 54, 57 and 58 that I’d like to restore, but better.

If this conversion works, will I be able to get away with a leaner mix ratio also?

[chris-p]

I have done quite a few Scott.

They idle real nice, start with ease. I highly recommend the conversion.

Yes, get all of the items from a ’61 to ’63

I think I have done a thread on this conversion with everything listed that you would need.

[chris-p]

Here is what you will need

Wrist Pin 307849 x2
Connecting Rod 378330 x2
Piston 378285 x2
Needle Bearing 378251×2
Big End Needles 378150 x2
Piston Rings 378416 x2
Circlips 302577 x 4

[Don]

I would stick with the recommended 24:1 mix.

[shoestringmariner]

Thanks Chris. Edit; I misread your post – thought you had the parts. I appreciate the shopping list however

Thanks Fleetwin. I thought I read that OMC went to 50;1 in the mid 60’s. Thought it might have something to do with a full roller set up. Love the classic motors, want to make them run cleaner if I can though

[Author]

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