I'm looking to have a spare trolling motor to take with me when I go on these longer trips for several days. A broken trolling motor can quickly ruin a good trip as we all know. So, I have 36 volt Ultrex and I'm hoping I can find a reasonably priced Fortrex as a spare but before I do that I want to be sure it will be able to fit in the Ultrex mount. Please help.