Re: 1967 Johnson 100hp golden meteor

[Don]

Has the mechanic ever worked on this model engine before, they are kinda tricky. You must remove the gearcase extension and gearcase as an assembly on this engine. I’m guessing the mechanic realizes the engine is electric shift and has disconnected the shift leads/harness.
If the splines are truly stuck, you may consider just hacking the extension apart and getting it out of the way to expose the driveshaft so it can either be attacked with an air hammer or cut off. But then you will have to find a new/used extension/driveshaft. This method should only be considered after making every attempt to coerce the gearcase down using Joel’s methods. You must be very careful when prying/wedging though, damaging/distorting the gearcase/extension/exhaust housing mating surfaces might cause the driveshaft/crankshaft splines to get out of alignment which will create premature spline wear.
Is this a salt or fresh water engine? For now, I would make sure your mechanic is familiar with this unique style engine and how to remove the gearcase before getting too involved with removing it "violently".