'56 Johnson AD-10 vs AD-10 M

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Sargent Skiff

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Apparently there were 1956 Johnson 7 1/2hp models AD-10 and AD-10 M.
According to the OMC parts book, there were different numbers for the gearcase and gearcase bearings, propellers and the tiller arm throttle rods. What was the functional difference between the two motors?
 
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F_R

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Re: '56 Johnson AD-10 vs AD-10 M

rjezuit said:
I don't know if this helps any, but its a cool site. Rick
http://old-omc.de/start.html
Click to expand...

The gearcase head and bearing assembly was changed, having a longer nosepiece where it goes up inside the prop. I think that had something to do with keeping fish line out of the seal. Anyway with that change, the propeller had to be changed in order to go over the extended nose. The complete gearcase number was changed because the just mentioned parts were changed.

In 1956, they made a change from stamped gears on the throttle shafts to cast bronze gears.
 
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Sargent Skiff

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Re: '56 Johnson AD-10 vs AD-10 M

Good info, thanks, FR. I understand now that an "M" designation indicated a mid-year change, which in this case, was obviously the bits you mentioned.
 
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