Re: lower unit issues
The shift shaft is probably installed backwards. You can pull the shift shaft out along with the plastic "plug" that it runs through and turn it around. It may not shift normally though. (FWD/REVERSE swapped) lower units get set up for counter-rotation partly by which side the shift shaft engages on the shift slider. I'd say turn it around and see how it shifts. When you are done it may need a different prop whether it ends up being a standard or counter-rotation unit.