I haven't seen anything in MinnKota's literature that says the engines
can't be run continuously. They claim that their motors run cooler than
other trolling motors. It's hard to imagine the motors overheating anyway
since they are submerged.
MinnKota has a Neptune line that is marketed for use as primary power
motors rather than trolling motors, but I've been unable to find out what's
different about the Neptunes, if anything. The guy on MinnKota's web page
who is supposed to be able to answer such questions didn't even know what
the Neptunes were. The only Neptune he knew about was the one that mounts
on the cavitation plate of a large outboard.
Harry Gordon
P14 #234, Manatee
Mountain View, CA