89 Evinrude 110 HP V4

[muskyhunter57]

I had to put a new lower unit on my motor this spring. I purchased one from a marine dealer in FL a few weeks ago. Unit came off a 90 Johnson. With the unit off the powerhead. The motor turns over and fires. I bolt it up and she will not turn over. Dealer tells me the driveshaft might be a little long and I could trim it with a angle grinder. Fine. I have done some grinding more than I think should be necessary. Same problem. Starting to think it's the diameter of the driveshaft causing the problem. New one is 1/16" of an inch thicker than old. Does anybody know if the area where the Crankshaft meets the driveshaft is a large cavity or is it fairly confined and could create problems like I am having? if I end up putting the old driveshaft in the new I am wondering if anyone can recommend a marine mechanic to do such work?

[boatfixer]

Does the new case seem to rotate fine before you put it on the engine?

The same drive shaft was used for several years back then. From about 84-90. 91 is when things changed. Do you know the exact year from which the new case came from?