Trolling Motor ?

[scbassman28]

I have a 55lb thrust on my 1648 Grizzly. My problem is it does not seem to have the power it is supposed to have. Even with a fully charged battery. What would be a couple things that might be wrong as to why i am not getting the power I am supposed to get.

 

[kofkorn]

How long is your wire run from the battery? What is the wire gauge? If you have a lot of resistance in the wires, you could be getting 2/3 - 1/2 of the power your motor needs. Can you check the voltage at the motor while it is under full load?

 

[RiverBottomOutdoors]

Quick thing to check would be take off the prop and check for line wrapped around the shaft.

 

[TNtroller]

suggest you check the condition of your TM battery as well, might be low on water, dead cell, bad cell, etc., have it load tested somewhere.

 

[shawnfish]

how old of motor is it? if its old the armature is probally worn out. you can try a new brush kit,that does the trick sometimes. id bet its one or the other if its not one of the suggestions above. brush kits are cheap and a new armature will run you 60 bucks if its a minnkota. one more thing to check is your magnets, if there is a peice or peices that are bigger than a i inch square then they need replaced. when you check your armature ur looking for any grooves no matter how small on the surface. if you dont wanna buy a new one you can rig it up to a power drill and have sombody hold the drill so the armature is vertical and get it spinning while you take a peice of 1200 grit sand paper and apply very light even pressure until you cant feel the grooves with your fingernail. but be careful not to over do it because if you take off to much it will make the power loss even worse. youll notice its a darker gold or copper color when you start and you want it to shine bright when ur done.
the small grooves and darker color interfere with the brushes contact on the armature and cause loss of power. im pretty sure i learned it from a thread on here, if you can find it with a search its pretty detailed on with pics if i remember right. anyways i did it to my minnkota and i must have did it right because i noticed the added power right away when i kicked it on at the lake.

 

[cva34]

Sounds like they covered it...cva34

 

[shawnfish]

Sounds like they covered it...cva34

covered what?

 

[JMichael]

covered what?

The possible reasons for his problem. :mrgreen:

 

[nlester]

I don't know what it is called, but years ago my brother-in-law gave me a stick about 1 1/4" square and 8" long. What ever it is, I can fire up a motor and press the stick against the armature to clean up the armature with the motor running. He did industrial maintenance.

In the old days when we use to turn armatures in a lath to clean them up, you could remove too much of the copper from the armature and the baklite seperators would eat up brushes until you used a v gouge to undercut the baklite and get it lower than the copper contacts.

 

[RiverBottomOutdoors]

If I had to go through all that, I would just buy another motor.

 

[johnnybassboat]

My nephew once had a 55 pound thrust MK trolling motor that didnt perform like he thought it should. He took the model # and serial # and called MK and they told him it was 24volts. Dont try this without being sure because it will fry your motor. [-X

 

[JMichael]

I don't know what it is called, but years ago my brother-in-law gave me a stick about 1 1/4" square and 8" long. What ever it is, I can fire up a motor and press the stick against the armature to clean up the armature with the motor running. He did industrial maintenance.

In the old days when we use to turn armatures in a lath to clean them up, you could remove too much of the copper from the armature and the baklite seperators would eat up brushes until you used a v gouge to undercut the baklite and get it lower than the copper contacts.

I've done a bit of shade tree mechanic work on old starters and other armatures that had a lot of wear. After sanding the commutator contacts, I'd use a hack saw blade to undercut the mica. Worked pretty good.

 

[scbassman28]

I do not know what you are talking about when you say the armature. Where is this located? I will try calling the manufacturer if i cannot figure something out shortly. I have replaced the battery recently and it still does not have the power that it should. So the battery is not the problem. The wires connecting the battery to the motor are about 16' long. they run from the back of the boat to the front and they are about as big around as the end of my pinky finger. Not sure of the actual size.

 

[nlester]

The hacksaw blade tip is a good idea.

The armature is a series of copper strips that your brushes rides on to provide electricity to your motor. If you don't have someone to help you who has some experience, I would probably leave it alone. Sometimes as a motor ages, it is best to live with what you have. Checking the voltage of you motor would be the best tip.

 

[JMichael]

The armature is the part of an electric motor that spins on most electric motors (unless you have an out runner which you don't in this case). The commutator is the part of the armature with the copper contacts where the brushes ride on. Considering that you don't know what the armature is, I'd say you're experience level is to low to be doing this type of repair yourself. If you can't get help from someone experienced with replacing brushes etc, I'd suggest you try to find a rebuild shop that handles starters, alternators, etc. Or you could just keep running this one until it dies and then buy a new TM.

 

[redbug]

The armature is the part of an electric motor that spins on most electric motors (unless you have an out runner which you don't in this case). The commutator is the part of the armature with the copper contacts where the brushes ride on. Considering that you don't know what the armature is, I'd say you're experience level is to low to be doing this type of repair yourself. If you can't get help from someone experienced with replacing brushes etc, I'd suggest you try to find a rebuild shop that handles starters, alternators, etc. Or you could just keep running this one until it dies and then buy a new TM.

that sounds like sound advice!!!! an electrical fire on the water is nothing to mess with even a 12 volt fire!!!

 

[scbassman28]

alright guys here are some pictures I took. Do you see anything that looks wrong?

 

[JMichael]

Well you've got it apart so I guess we're doing this anyways. :lol: From what I can see in the pics, everything looks pretty normal for a motor that's been in use. Make sure the bearings turn smooth (no gritty feel) and easy. Take some fine sandpaper and sand the commutator contacts until they are smooth and shine like a new penny. Be careful not to damage the clear insulation that's coating the copper wire on the armature. Make sure the space between the individual contacts is clear of any metal (pieces of copper) and that the material between them is lower than the surface of the copper contacts. Here's a link that has some useful info about the contacts and the mica.
https://martindaleco.com/HTML/MetalWorkingMicaSaws/Helpful_Hints_MicaSaws.htm As I stated earlier, you can achieve the U slot with a hack saw blade if you are careful and take your time. Be sure to spray the commutator with electronics cleaner to rinse away and copper or mica particles after you've finished sanding and cutting the mica down.

 

[nlester]

Thanks for putting it together Mike. Besides needing to undercut the mica to keep it below the copper strips, too much sanding could create a burr on the edges of the copper that would require undercuting to clean it up. Now I know the name of the stick that I use to have to clean the armatures of the motors in my shop, a commutator stone.

 

[JMichael]

Forgot to mention anything about the brushes so I'll add a few words on that. They don't appear to be worn out but pictures can be deceiving so you'll have to make the call on that. Get a can of brake parts cleaner and spray the brushes and surrounding area to wash away all the dust created by the brush wear. Inspect the wires connected to the brushes for frayed or broken strands. Slide the brushes back into their holders and push them in/out a few times with your finger to make sure they aren't hanging and that the springs are pushing them out good. If you see any problems, you might want to install a brush kit. And just as a double check, look at the sides of the armature and make sure it hasn't been rubbing on the field magnets.