Remove the prop and make sure there isn't any fishing line wrapped around shaft. See if you have side to side play (bearing), bent shaft or seal damage. Rotate the motor and you should feel just equal resistance as it aligns with each pole. If it feels rough, there is probably internal work to do. Outside of fishing line, it will probably take a teardown to fix. Depending on model, that can be straight forward or allot of fun. Find an online schematic and parts diagram to review before just tearing into it.
My motor guide did the same thing replaced the brushes works fine .Take the top off check for corosion first .Was a pretty easy fix
id send it to them i got mine all a part and back together 3 times now and it just wont work the same MINN KOTA will fix it up for a price and it will definatly work for quite a bit shy of 1300