noisy trolling motor (video included)

i picked up a used minn kota endura with hopes of getting onto metro area electric-only lakes this summer. intended use is just to get launched legally. will mostly be at anchor or drifting.

i have zero experience with TM’s, but this doesn’t seem right.

First off, the wires for forward and reverse must have been switched by the previous owner? with the motor mounted on the transom, reverse gears push the boat forward, while the forward gears pull it backwards.

Second, the motor seems loud in general, and intermittently it can get VERY loud. Thinking I may have wasted my money (not much, thankfully) on a damaged unit, but figured maybe someone here would have a suggestion:

That doesn’t sound good at all. Maybe a seal is leaking and you can clean it out, grease it, and the seal can be replaced. Doesn’t cost anything to take it apart. I would expect the worse though. Hope you didn’t pay much. Whomever sold that to you is an A-hole.

mojogunter wrote:

That doesn’t sound good at all. Maybe a seal is leaking and you can clean it out, grease it, and the seal can be replaced. Doesn’t cost anything to take it apart. I would expect the worse though. Hope you didn’t pay much. Whomever sold that to you is an A-hole.

I only paid $40. I know, ya get what ya pay for — but when I look someone in the eye and ask “is there any damage that i should be aware of?” and they say all’s well, shake my hand and take my money, it’s frustrating. people are pathetic. dude must have really need that $40.

Regarding forward and reverse. Which way is the prop pointing in relation to the handle? You can turn them around 180 degrees to act like a back trolling motor. Otherwise, is it possible you have positive and negative terminals reversed? Not sure if this applies to DC motors though.

It’s hard to say what the noise is but it sure sounds like there’s some undesirable interference happening there. I’d say take her apart for a look see.

Hmmmm…..I’d pull the prop off and look in there to see if maybe it’s full of fishing line or something that’s would up around the shaft. How does the prop look, any major dings in it? And finally (and I hate to even mention this) are you sure you have the battery cable hooked up with the right polarity? If it’s backwards, that might account for the forward/reverse problem.

SR

Check the prop and prop shaft. Could be something as simple as junk between the housing and prop, missing the drive pin on the shaft that the prop sits on, possibly a bent shaft, or bad bearings. Which if I recall aren’t too difficult to replace.

There really is nothing much to the unit other than the head which houses the electronics and the lower unit which houses the motor, so even if you need $20 in bearings it still isn’t that bad for that machine.

biggill wrote:

Regarding forward and reverse. Which way is the prop pointing in relation to the handle? You can turn them around 180 degrees to act like a back trolling motor.

Yes, that’s very likely the reason for the fwd/rev being switched. Uncrew the single bolt where the top of the motor meets the shaft, rotate 180 degrees, and put the bolt back in.

I agree with Steve, take the prop off and check for line.

Pull the prop and make sure the little pin that goes through the shaft is there.

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I vote for bad bearings and seal.

Thanks everyone. Will open it up and report back.

When I got it, the head had been flipped for backtrolling or bow mount. I switched it back, so now the handle faces into the boat where I can reach it while the prop faces out to the wake like the outboard. My battery cables are on the correct terminals. I’m thinking maybe the previous owner also reversed the power cable connections inside the head. If used for backtrolling this gives 5 speeds in reverse vs 3 forward.

From memory, there is a slight ding in one of the prop blades.

Ok, found a good bird’s nest of line and weeds when I pulled the prop. Cleaned all that out, reinstalled the prop, and did a test run in my garage. Obviously comparing apples to oranges in & out of the water, but this still sounds loud to me? Sounds like maybe I need to take closer look at the bearings, seal, etc?

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Good chance it’s a bearing. All that line around the prop can cut into the seal and cause leakage into the bearing or motor. Probably needs a little more investigation.

If you run it without the prop on it should be nearly silent.

Does the power seem to be surging or intermittent? If so you could have some serious leakage into the motor.

biggill wrote:

Good chance it’s a bearing. All that line around the prop can cut into the seal and cause leakage into the bearing or motor. Probably needs a little more investigation.

If you run it without the prop on it should be nearly silent.

Does the power seem to be surging or intermittent? If so you could have some serious leakage into the motor.

Thanks biggill. Need to track down my neighbor to borrow some tools to pull the bearings. The power’s not intermittent or surging.

Do a search there are places that sell rebuild kits. They are pretty basic once you figure out how to get it apart. Just remember the magnets hold the armature in place so it takes some force to pull it out.

The way the sound changed as you steered the motor makes it seem likely that the bearings are bad. The motor appears to run well, and MK probably has a service center in the Cities that could give you an idea how much it would be to replace the bearings and seals.

With the boat up on blocks while I have a new axle put on the trailer, I’m finally getting time to dig into this. So much nastiness in there. I’m really not sure I’ll be able to resurrect this TM, but I’m gonna give it a go and at the very least learn something in the process. This morning I opened her up. I’ve pulled the armature out it’s quite obvious that all bearing and seals are trashed. Needs a good cleaning and then I’ll try to piece it back together. I haven’t been able to get the brush housing out yet, as the small bolts had a lot of rust on them and I don’t want to strip them. Some naval jelly sitting on the heads right now, we’ll see. If I can get that out safely I’ll order the replacement parts. For now, nasty pics!

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Yikes!

One of th more important things if you get it all cleaned up is to make damn sure it’s sealed off so you don’t get water intrusion again. With all those different metals, EVERYTHING including aluminum will oxidize with the presence of the slightest amount of acid.

With a little elbow grease you should be able to get some use out of it.

Very good picture of the inside. A good learning tool for someone who may need to take one apart. Remember to be gentle with the magnets on the side of case. You know if you crack one the motor is no good. Good luck with it.

Thanks for the tips guys. I will proceed with caution. No luck unfreezing the bolts that hold the brush plate into the rear housing. I think I’ll just do my best to clean around that, as there doesn’t appear to be any parts I need to access behind that plate.

I’m attaching the diagram for reference. If anyone has done this and can confirm I’m on the right track with the following, I’d appreciate it!

Replace:

brushes, part 9 (these look OK, but for $3 as long as I have it open…?)
ball bearing, part 8
O-rings, parts 17, 18, 19
seals, parts 6 ad 7 (any advice for how to pull these out of the flange bearing?)

Speaking of the flange bearing (part 24): The parts list on MK’s site has that part listed as “service only.” It’s the only part indicated as such. It looks to be in great shape. Is this something I need to replace as well?

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if there is any doubt, change it out.