I've got a Powerdrive50. Question is should I use an inline fuse, circuit breaker or nothing? The book says nothing about it.
Rob's motor looks to be wired without one.

Hey Jerry:

I never put a circuit breaker on my PowerDrive. And I never had any problems. However, for all I know, maybe through time not having a circuit breaker caused a bit of "frying" and subsequent loss of power through the years.

If you are going to do it I would put an inline 50 amp circuit breaker complete with power swith into the positive feed.

Did you ever solve the problem of how to mount your motor to your boat?

Yeah, I got a quick release plate for it. I was able to get 3 of the 4 bolts in the bow, then I built a little box that's attached to the deck. It acts as a mount and place to put the plug. It is made of wood, but the motor mount is solid, even without it.

I don't have any fuse or circuit breaker on my trolling motor. I haven't heard that is necessary but I'm not much on electrical stuff.

I would use a 50 amp breaker just in case. The breaker will save your motor should something happen. Then you just push the switch to reset it if it trips.

Electrical is like this:

The motor will only use the amount of amps required to create the power it needs. But after time the brushes wear and creates more ohms (resistance) so it will take more amps to create the same amount of power to turn the motor. Think of electricity like water flowing in a hose. Voltage flows with no resistance. Amps push the water through the hose when there is resistance. When you kink the hose it creates more resistance and then you will need more amps to push the water through the hose.

The fuse or breaker is designed to protect the circuit from over amperages that will burn the intede source of the power. Once you burn the circuit either the wires or the circuit board/motor it is damaged. It may still work but not to it's full potential. Once you let the factory smoke out of the circuit it's done. (all electrical components come equiped with smoke inside from the factory so don't let it out :D)

If you guys ever have any electrical questions just ask me. I have a ton of electrical knowledge from my time of auto repair with Toyota and several other automotive repair shops.

Having no short-circuit protection in a boat (especially a fiberglass one) is asking for trouble due to how fast a boat can burn. With aluminum boats being conductive the boat itself can become the short circuit .Some trolling motor makes come equipped with a circuit breaker mounted in the foot pedal sized to protect the trolling motor . This will only protect the circuit from the breaker down stream to the trolling motor leaving from the bow plug wiring back to the batteries unprotected. A circuit breaker should be installed to protect the wiring running up to the trolling motor plug based on the wire size . #10 wire = 30 amp , #8 = 40amp , #6 = 50 amp .
A trolling motor battery is capable of incredible amperage in a short circuit condition determined by the resistance of the short .
Lets assume that we're running a 24 volt battery system that draws 24 amps at full load (just to make the math easier)
Using "Ohms law" we can calculate circuit resistance at full load /24 amps 24volts divided by 24 amps = 1 ohm resistance
Now lets say your trolling motor wiring has damaged insulation resulting in a direct positive to negative short circuit .
Now the only limiting the short circuit current is the resisitance of the wire ( lets assume .01 ohms)
24 volts divided by .01 ohms = 2400 amps ! I don't think the batteries could put out that much current but bad thigs are going to occur with no protection such as wiring catching fire,boat catching fire , batteries exploding . West marine has a great assortment of marine circuit breakers (that just where I buy my stuff) and I would recommend adding one if you dont already have one in your boat .