Alright so I have a brand new Minn Kota Maxxum 70 pound thrust and 52 inch shaft.  When I deploy it from the stowed position using the string assist into the down position, the metal lever that is supposed to lock into place to hold the motor in the water doesn't fit into the slots - it just sits on top.  So I can use the motor on low power but if I turn up the power, the whole motor pops out of the water.  Any thoughts.  I've used minn kota bow mounts for many years and they've all just snapped into place when I put them down.  I've put considerable force on top of the maxxum to try and get that lever into the slots without success.  I know its not bent either, because its literally brand new.

Make sure there is nothing preventing/interfering with what I'm gonna call the top half of the assembly from going all the way down other than what you're calling the lever. Make sure there is nothing keeping the lever from traveling as far as it needs to as well. Given that it's new, if it's not an installation issue or obvious fix, I would exchange it. 

I've seen this happen when the motor wasn't installed far enough forward and the shaft was hitting the bow when it was just about at full deploy. Make sure it's not hitting anything and nothing is stuck inside the bracket that might be holding it up. 

And if it all checks out, call minn kota. 

I had to take a file to a mount a few years ago to correct this same problem but if yours is new I would take it back to Minn Kota.

I took it back into the repair/marine service center and a tech immediately noticed the problem.  There were nuts sticking up about 1/4 inch preventing the top half of bracket from completely falling into the bottom half of bracket, therefore not allowing the lever to reach the slots.  He said whoever installed it put the screws and nuts in backwards, as the nuts are supposed to be facing downward, not upward - with the top of the screws flush with the bracket.  Problem fixed now, thanks.