Re: Yamaha 40hp. mamual, shortshaft
Hmm, if you can find the model number on the transom bracket then you can verify the year, if it ends with an "R" it is indeed a '93, a '95 will end with a "T" and the following models are all 1993 year 2-cylinder 40hp 2-strokes, according to the actual parts look-up from the yamaha site...C40ELRR, C40MSHR, C40PLRR.
The "high torque" gear case is not something I really know much about, other than they've offered high torque or high thrust cases on some of their smaller motors for quite some time now. Popular on pontoon boats and for commercial use.
Hope this helps some. Do a compression check and maybe see if you can have a yamaha mechanic check it out?