Max Power thruster knocks one way, works the other

[HONUHYC]

I have a Max Power thruster on my GB42 that has never had any issues. Today, when crossing the harbor to pump out, it worked fine in one direction, but when the joystick went the other direction, it made a fairly loud knocking sound at around a one second interval, maybe a bit shorter. I saw a few things in the MaxPower troubleshooting guide that discussed why a thruster would work only in one direction, but nothing on the knocking, which I am thinking might be an indicator of what the problem is. Web searches and searching the forum have not turned anything up, although my search strings may have missed the mark. Any ideas out there?

Thanks in advance.

 

[ScottC]

My first thought would be checking for debris. I've heard my bow thruster make various different sounds when fouled with debris while cruising in canals. Though, "knocking" is not a word I would use to describe any of the sounds I've heard. Easy enough to check, though!

 

[Choices]

Mine tried to hang up from grass on the bottom.

A knocking could be a barnicle, although it should be fast.

Otherwise it might be low voltage from a bad connection.

 

[Arc]

Change in speed of the thruster could make it ‘knock ‘ . That means electrical or obstruction.
A cracked prop will also do it. Time to jump in.

 

[AlanT]

Maybe a loose anode? The knocking is a lot slower than the rotation speed of the prop obviously so it's not something on the blades, but it could be loose anode, or worn bearings(Unlikely). I suppose the prop could have got hold of something and be banging it against the hull. As others have said, time for a swim.
~A