Minn Kota 95 Trolling motor repair questions -- loose magnets

[SteveVT]

I have an old but little used Minn Kota 95 trolling motor. Parts are no longer available from Minn Kota for this older model.

Just turning the prop by hand made a clunking sound, so I opened it up and found that the magnets had come loose and were stuck on the armature.

I'd like to epoxy the magnets back to the case sides, but there doesn't seem to be any positioning marks to guide me. I can see where the glue came loose but it's just an irregular blob shaped mark, since they obviously didn't do a great job of the gluing. I don't know how far int the case to put the magnets or exactly how they go "around the clock".

1.) Wondering if any clever person here can come up with a way to decide how to position them?

2.) Any photos of a healthy "95" showing the position of the magnets, and a couple measurements of the depth and spacing between them would be GREATLY appreciated!!!!

Thanks for any help.

 

[gm280]

SteveVT, how many magnets are you talking about. If two, then it would make sense that are place 180 degree from each other. Now where on the housing that place is, would be determined by the glue you see inside. If they are placed in that glue area and the other 180 degrees on the other side, it should work like before they came loose.

I had magnets come loose on a 15 HP lawn mower engine and I used JB Weld to re-epoxy them back. I never had any more issue since then. So a good quality epoxy will work toe replace them back. JMHO

 

[SteveVT]

Thanks gm280! Yes two magnets.

I'm pretty certain now the magnets are opposite eachother, as you say, and probably on a vertical line.

I was worried about getting them exactly aligned like the factory because of timing -- a few degrees could make a difference. But I just realized that the way the two end caps w/brushes are bolted together (and not to the center section) allows you to rotate them a little, so you can adjust the timing. So it isn't super critical where the magnets are to a few degrees, as long as they are directly opposite each other. That should be easy to do by measuring the spacing between them on either side.

The only two problems left are how deep into the case they go, and which one goes on top, since one is a North magnet on the interior, and the other a South magnet. If I get that wrong the motor will turn the wrong way. I think the different shaped glue blob lines can tell me which one was where.

But how far in they should be is pretty hard to tell from the glue lines. Unfortunately, they didn't put glue out to the edges, so there;s no sharp line where the end of a magnet sat.

Maybe I can figure it out by replacing the armature without the magnets and measuring how deep the rotor laminations are -- that should be where the magnets are positioned.

Okay, I think I've got it now -- and I was definitely planning to use JB Weld to glue them back in. Love the stuff!

Thank you kindly gm280 -- I'm sure you're right now. Will let you know how things work out.....

 

[gm280]

Thanks gm280! Yes two magnets.

I'm pretty certain now the magnets are opposite eachother, as you say, and probably on a vertical line.

I was worried about getting them exactly aligned like the factory because of timing -- a few degrees could make a difference. But I just realized that the way the two end caps w/brushes are bolted together (and not to the center section) allows you to rotate them a little, so you can adjust the timing. So it isn't super critical where the magnets are to a few degrees, as long as they are directly opposite each other. That should be easy to do by measuring the spacing between them on either side.

The only two problems left are how deep into the case they go, and which one goes on top, since one is a North magnet on the interior, and the other a South magnet. If I get that wrong the motor will turn the wrong way. I think the different shaped glue blob lines can tell me which one was where.

But how far in they should be is pretty hard to tell from the glue lines. Unfortunately, they didn't put glue out to the edges, so there;s no sharp line where the end of a magnet sat.

Maybe I can figure it out by replacing the armature without the magnets and measuring how deep the rotor laminations are -- that should be where the magnets are positioned.

Okay, I think I've got it now -- and I was definitely planning to use JB Weld to glue them back in. Love the stuff!

Thank you kindly gm280 -- I'm sure you're right now. Will let you know how things work out.....

Sounds like you are now rethinking their position. And I also think you have it correct as well. I would certainly look at each magnet and see the glue pattern, even if it is a mere faint line, and replace them as it becomes obvious. And I think you will have a fully functioning trolling motor once again. Remember, they built these as quickly as they could. I don't see micro adjustments being made to get the last drop of efficiency from them. JMHO

Post your results though. These forums help others with similar concerns about their trolling motor. :thumb:

 

[SteveVT]

Thanks gm280. I was able to get the magnets lined up correctly after looking carefully at the shapes of those glue lines in a really strong light. I marked each magnet on the inside with grease pencil for top and bottom and also an arrow pointing to the motor cap end. I then put a very thin layer of JB Weld on both the motor case and the magnets, slid one in position and clamped it lightly with a spring clamp, then did the other one. I adjusted them.

Their glue lines get covered up, BUT the bolt holes for the two through bolts and their bosses gives you a position to sight them down, because the bolts go half way between them.

The two gaps between magnets I checked with an old el cheapo plastic caliper I had, to even them out. It's non magnetic.

I did find one bit of glue line for a reference to how far past the case edge the magnets would go. Before adding glue I had put that magnet in place and measured the distance to the edge. So I had that measurement as a reference.

I sanded the inside of the case where the magnets would be glued, and wiped it out with xylene. It was then that I discovered that the magnets had probably been glued in originally with contact cement. The xylene softened that, and it was pretty obvious what it was. Why couldn't they have used epoxy!!! Would that have added $1 to the production cost? I probably used less than $1 worth of JB Weld even retail.

Anyway, It's all glued up. I added some screw clamps after everything was positioned -- but tightened them lightly and carefully -- didn't want to break the magnets -- they're fragile, and there were a few short (1/2" long) hairline cracks in their edges already from age. Once the backing epoxy sets, I might wick some CA (superglue) into those cracks to keep them from spreading.

I will definitely report on the final operational outcome!

Thanks again, and hope this does help someone else....

 

[SteveVT]

Positioning while gluing the magnets back in place:

 

[SteveVT]

Well the good news is it works! The switch looked like new, and acted that way as well. Five forward speeds and two reverse on this 8 position switch. This motor has had no water incursion and little use. It was only used in fresh water, and probably had ten hours use.

I put everything back together yesterday to test. I didn't add any bearing grease or sealing compounds because I'm waiting on delivery of those for my '63 Evinrude project. I plan to open the Minn Kota up again to lube and seal (if advisable) as needed, and paint the case where paint has flaked away. The interior components were like new -- zero corrosion and everything was shiny. But the case outside had suffered over 25 years of sometimes damp storage.

Also not quite sure what I should use for sealing and lubing. Advice would be appreciated. I have 3M #847, and OMC BRP compound coming in the mail, and have marine grease on hand. There are two bearings, which look like they might be Oilite (sintered), though I'm not sure. If so, I'm not sure they would need additional lube, though, I found evidence of grease near the rear cap bearing -- it is swivel mounted.

The two case seals are 4" dia, I think they may be shaped plastic -- but might be rubber O-rings, I'll have to double check when I open the case again for final assembly. Then there are two small O-rings on the case bolts. Finally there's a special shaft seal after the prop bearing -- probably hard to find a replacement for.

I would like to renew all the seals, but since this trolling motor has been obsoleted, no kit specific to it is available.

I do wonder if a 4" later motor's seal kit would work on this one, but the Minn Kota site is no help for a cross reference. I guess I may have to cross my fingers and hope the old seal will continue to work. Unsure whether to lube the motor shaft there, as well.

Thanks for any help/suggestions!

 

[SteveVT]

Update:

After doing a lot of searching online and reading part descriptions, I believe the seal parts kit to fit this motor is still available as Minn Kota # 2889460, even thought they officially list the motor as "obsolete" and don't show the kit for it on their support site.

But when I did a search for the part number there, it came up as available, so I ordered one kit. We'll see if it fits. I also found a seals part diagram, for the various sized motor housings here:

https://www.minnkotamotors.com/WorkArea/DownloadAsset.aspx?id=3133

 

[gm280]

Sounds like you have it all fixed up now. Usually the seals are used for more then one trolling motor. And they probably use the prop type seal on many other models as well. I think you did good checking part numbers and not merely going by the (NLA) no longer available listing. I do that all the time with obsolete parts. Seems they list them as obsolete but use the same parts on newer models. Interesting isn't it. So doing some clever research can usually find a part even when it isn't listed as a available anymore. :thumb: