[robertjp]

I have a minn kota 40 lb transom mount that I just took apart and cleaned and sealed. Now it is making a high pitch humming noise that is very annoying. Does anybody know what would cause this (bearing?, brushes?, prop?) I dont know if there is anything else that moves. Anybody? Thanks

P.S it is a high pitch whistling/humming noise. It does it most of the time but sometimes it doesnt do it.

[rndn]

Are you sure it's a Minn Kota and not a Hummingbird?
Seriously, is it humming or making the noise only when the prop is spinning, or is it more of an electrical hum that sounds whenever there is power to it?

[jtexas]

I just did my motorguide. Haven't had it on the lake yet but I experienced something I have a feeling might be related. Not the same sound, but anyway...

Did you use a torque wrench on the thru-bolts on final assembly? If they aren't the same tightness, could be just enough misalignment to make something rub something it shouldn't. If yours is anything like mine, the clearance between armature & field magnets is paper-thin. I'm talkin tissue paper, not the stuff your resume is printed on.

I also discovered that the spec on mine is 48-50 inch lbs - it did way better when I backed off on those.

[robertjp]

Im gonna try the thru bolt suggestion per Minn Kota. They both have to be the same tightness. Yes it hums/whistles when the prop is spinning. Stay tuned.