Re: Replacing the clutch dog on a 1957 35 hp johnson

[Don]

At this point, I would question the ebay seller and your mechanic as well….Perhaps the seller sold a faulty gearcase, but I find it hard to believe your mechanic did not figure out the gearcase was NG before collecting his money and returning the rig for you to discover it does not work properly.
There are a few possibilities here:
the ebay seller sold you a faulty gearcase
Is you engine a long shaft? Perhaps you were sold a 15" gearcase and the driveshaft is too short, did you notice if it was pumping water while you tried to use it? The crankshaft splines could be wiped out as well…
Your mechanic failed to connect the shift linkage properly and adjust the shift cables/linkage properly. Did you try to shift the engine by hand with the cable disconnected?
There is a problem with the engine’s shift linkage/bellcrank/handle, follow Frank’s advice for checking this out
Perhaps you have a sheared drive pin?
Perhaps the rubber hub in your propeller is NG.

Have you contacted the ebay seller? Is he willing to take the unit back/refund you? Again, at this point, I don’t have much confidence in either the seller or your mechanic….