Re: Jumps out of reverse
          Sounds like its possible that , when trimming .
      The angle of the motor is somehow, putting the shift cable , rod,  linkage, something in a bind.
      Then when lowered its not.
        Thats what I'd check first .
        Seems if it was a problem in the gearcase , motor trim / angle, wouldn't make any difference.
         ie: a worn clutch dog , is a worn clutch dog, whether trimmed up / down.
      Though, I've never encountered your symtoms.
      Maybe someone that has will respond.
                       KYHunter