by spanky » Tue Feb 28, 2012 8:49 am
I also have a 21.70 {great boat} I went thru a trolling motor company that was at our local boat show.For that size boat they recommended a 80lb. I went with the Minn Kota, had it a few years now with no problems with it. Pulls you around in the wind with no problems.The battery wires are in the center concole,2 reds and 1 black.They only used 1 red wire,dont know what the 2nd red wire is for unless its used in the 36 volt set up. I let them install it because they only charged 50.00,not worth the headache to do it myself and i know its done right.Hope this info. was helpfull.