Minn Kota Terrova Leaking Water From Head Unit When in Stowed Position

[MainelySmallmouth]

I had a "new to me" trolling motor installed on my boat this spring. After my first to two or three trips of the season, I noticed what looked like muddy water dripping from the head of the trolling motor on the rail of my boat. I have had RipTides and Ulterras before on my boat, and I have never noticed this taking place before. Is it possible that the trolling motor head unit is taking on water (broken seal somewhere) and leaking water up the shaft (is the shaft hollow) into the head unit? Is that possible?

Anyone else ever seen this happen before? If so, what was the cause and is it a big deal, ie do I need to get something fixed?

Thank you for reading and I look forward to your post. Tight lines!

[Bradrodfish]

You have water intrusion in the motor. Dirty black water is not a good sign. The motor unit and the shaft will have to be replaced. S/N? Look it up in the Minn Kota parts website.

[billnorman1]

The shaft is hollow. It is screwed into the motor with sealant to stop water intrusion. If the motor leaks water into it, usually by loose screws behind the prop or bad O rings there (3, 2 little 1 big) it can run up the shaft. If the shaft is broken or cracked it will leak. If you have a built in transducer it can leak. All of the above are bad.

[Bradrodfish]

The shaft is hollow. It is screwed into the motor with sealant to stop water intrusion. If the motor leaks water into it, usually by loose screws behind the prop or bad O rings there (3, 2 little 1 big) it can run up the shaft. If the shaft is broken or cracked it will leak. If you have a built in transducer it can leak. All of the above are bad.

Bill the shaft on a Terrova is not screwed in it is machined in and glued at the factory. The motor assembly and shaft comes as one unit.

[MainelySmallmouth]

UGH..... This was my fear..... The O rings would be a simple fix/solution, but my next question is that is it, what is the long term prognosis for the water that has been leaking into the unit??

[Bradrodfish]

UGH..... This was my fear..... The O rings would be a simple fix/solution, but my next question is that is it, what is the long term prognosis for the water that has been leaking into the unit??

The motor will quit turning and will leave you dead in the water. What has happen already is the water has caused the brushes to ware and leave a film on the commutator. It will cake up so bad that eventually the motor will not spin. You could just change the brushes and the armature, but you still have to speed a great deal of time cleaning up all the mess inside the motor. Even then you still won't know where the water is getting in. So it is best to just replace the whole thing.

Find your serial number and the attached diagram has a complete break down of the Terrova motor. It will tell what you need.


https://motors.johnsonoutdoors.com/P...nd_Controllers

[billnorman1]

Bill the shaft on a Terrova is not screwed in it is machined in and glued at the factory. The motor assembly and shaft comes as one unit.

Not to contradict, but I just looked up the 24 volt Terrova and the parts diagram shows the shaft, seal and motor housing as separate pieces, although not separately procurable. Therefore it is not inconceivable that this juncture can leak.

As far as whether it is screwed or some other method is used, that is not explained, and I do not know the method used. I also do not know whether the shaft is hollow but getting wires down a solid shaft could prove difficult.

[erico]

So I had the same thing with a brand new one last season. After 6 weeks in the shop and 3 separate trips to 2 different service centers, they finally replaced the shaft/motor housing. It could be the seals, wasn't with mine as they replaced them twice with no fix. Bradrodfish is right about the glue, apparently mine passed QC and left the factory not glued and sealed properly which is where the leak was.

Good luck

[PJ-Rohlf]

Same issue with had with ultrex. Must replace shaft and lower unit housing if seals don't fix it. Was also a pain trying to convince the ASC that it was the issue until they saw more of them.

It wasn't until one day when I half way stowed that I could see drips of water coming from the shaft/motor connection.

[rocknemo]

First off dont go out buying a new head and shaft or anything else, I've have done a few with water intrusion to the point where the motors wouldn't turn until you helped it. Its not that difficult to take the lower head assembly apart, from there you can remove the armature to inspect the housing. Take everything and thoroughly clean any oxidation from the Magnets and the armature, use fine steel wool or sand paper to polish the copper surfaces. totally clean all the mating surfaces, thru bolts and inspect orings, replace if any nicks or deformation. Put it back together and it will be good and new. Its not as difficult as you would think and most times you wont need to replace any parts.

[MainelySmallmouth]

I really appreciate this post, and it sounds like my Marine tech could probably spend a couple hours and get it cleaned up.
Thee only question I have is how to identify the source of the leak and water intrusion? I'm concerned that there is a leak in more than one location and if I don't identify accurately where the leak is, like the shaft to the motor union, or a crack in the shaft, or through faulty seals ( which I believe you be the case) I feel like I'll just be chasing this again in the future.??

First off dont go out buying a new head and shaft or anything else, I've have done a few with water intrusion to the point where the motors wouldn't turn until you helped it. Its not that difficult to take the lower head assembly apart, from there you can remove the armature to inspect the housing. Take everything and thoroughly clean any oxidation from the Magnets and the armature, use fine steel wool or sand paper to polish the copper surfaces. totally clean all the mating surfaces, thru bolts and inspect orings, replace if any nicks or deformation. Put it back together and it will be good and new. Its not as difficult as you would think and most times you wont need to replace any parts.

[equalizersmm]

I have used a wash tub filled with water and put the motor in it, you'll see air bubbles coming from where it is leaking.

[MainelySmallmouth]

Thank you! I appreciate the feedback. I purchased a used trolling motor from an eBay seller, and all I can say is what I disaster. I believe I know where the water intrusion is coming from, which behind the prop, as there are supposed to be two seals that go around the main shaft, both of which are missing. I didn't know anything was wrong until after I started using the trolling motor and I was getting water leaking from the head after the motor was stored. Needless to say, because I live in Maine and our boating season really doesn't start until Mid April, it took me a while to find the issue and as a result I lost out on my eBay money back guarantee and the seller totally left me in the lurch. I essentially, I was sold a defective motor with no heads up and I still paid a pretty substantial fee for a used Terrova, 2013 production year.

I just ordered the seals, and I am going to have my marine tech tear into it and have him check it over. I also ordered the complete replacement shaft and motor in the event the repair doesn't hold, ie back up, as I can't be without a trolling motor during the prespawn/spawn (wait all winter for this time period to fish)....

Thanks again for all the replies. I appreciate it...

I have used a wash tub filled with water and put the motor in it, you'll see air bubbles coming from where it is leaking.

[billnorman1]

Well....not having ANY prop shaft seals can cause issues. Wow!

[MainelySmallmouth]

I know... I learned a valuable lesson about what to look for in a trolling motor when buying from online sellers. I knew something was up after the first use when we had dirty colored water leaking from the head of the motor. I just thought it was "odd" and sort of moved on, but it kept happening and I decided to see if others have had similar experiences here on BBC. This thread has been very helpful. I was sold a defective item from what I know realize is a less than credible seller. His response was well you said you have had it out a few times and all looks good, and if there was a problem you should have reported it on the first use. I would definitely suggest any eBay users stay away from seller KSIUSEDPARTS123, which is Ken's Sports in Wisconsin. Buyers beware....

Well....not having ANY prop shaft seals can cause issues. Wow!

[Kodiak16]

You need to rebuild the motor. New brushes etc. Cost me $450 for motor and shaft rebuilt.

[MainelySmallmouth]

I was able purchase a new shaft and motor for $400, plus roughly $400 to disassemble and remove the current shaft and motor and install and power up the new one. I also picked up the missing shaft seals in the event my marine tech can clean/restore the motor after pulling it apart for inspection (which will still cost me $300 in labor at three or so hours). So not a cheap fix/repair at all.

[billnorman1]

A very unfortunate experience, our condolences.

[MainelySmallmouth]

I will survive. I learned a few things through the experience, so I won't make that mistake again. Onward and upward. Just trying to make sure the motor is running through the pre spawn and spawn. I wait all winter for this fishing "season", so hopefully I can be on the water without any issues.

A very unfortunate experience, our condolences.

[Extremeboating]

Thank you! I appreciate the feedback. I purchased a used trolling motor from an eBay seller, and all I can say is what I disaster. I believe I know where the water intrusion is coming from, which behind the prop, as there are supposed to be two seals that go around the main shaft, both of which are missing. I didn't know anything was wrong until after I started using the trolling motor and I was getting water leaking from the head after the motor was stored. Needless to say, because I live in Maine and our boating season really doesn't start until Mid April, it took me a while to find the issue and as a result I lost out on my eBay money back guarantee and the seller totally left me in the lurch. I essentially, I was sold a defective motor with no heads up and I still paid a pretty substantial fee for a used Terrova, 2013 production year.

I just ordered the seals, and I am going to have my marine tech tear into it and have him check it over. I also ordered the complete replacement shaft and motor in the event the repair doesn't hold, ie back up, as I can't be without a trolling motor during the prespawn/spawn (wait all winter for this time period to fish)....

Thanks again for all the replies. I appreciate it...

This statement worries me a little. If the leak is indeed coming from behind the weedless wedge prop, then that makes me have to ask, how much did you tighten the prop retaining nut onto the shaft when you first installed it?

If you went too tight then it is possible that the failure was not actually a QC failure after all.