# how to remove generator?



## critter91 (Feb 27, 2008)

i recently got an old portable montgomary ward generator and i want to take off the generator for a go kart or mini bike project. i have the generator cover off and the two set screws off the engine output shaft. but this thing will not pry out. i have greased for about two days now but was wondering if there was a method to doing this?


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## paulr44 (Oct 14, 2008)

I'm not familiar with Mont.Ward gensets, but here's what I can tell you.
Most generator rotors are tapered, as is the engine crankshaft.

Problem is with that, almost nothing else save for maybe somewater pumps use a tapered fit.

If you do need to remove the rotor....

The taper fit retains it's hold, and doesn't just pop apart.
If the rotor had a through bolt going into the crank, you can use that hollow to create your own puller bolt set-up. If not, you'll have to describe the retaining arrangement for us.

Look to see if there are threads in the end of the rotor. If not, you can usually tap some into it. You need to have threads in about 1".
You need a long, hardened shaft such as a piece of old "weed-whacker" driveshaft, and a bolt with threads matching the rotor end.
I'll call the weed-whacker segment the "insert," and the bolt, the bolt.
The insert needs to pass through the crankshaft threads and bottom out, so it doesn't damage the threads. It must be long enough to reach to almost the end of the rotor when inserted. You then tighten the bolt up against it, pre-loading it well, then smack the head of the bolt with a 3-lbs. sledge. _You have to be extremely careful not to miss and hit the rotor windings or slip rings._
It may take a few smacks, and a few re-preloads of the bolt, but without having a complete puller bolt, one where the insert and the bolt are made as one, this is a good homebrew set-up.
Honda makes nice ones to fit there gensets, and Generac makes inserts to fit theirs with threads on the end to fit into the cranks (but no heads or upper threads - only one end can be threaded else it won't work).


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## critter91 (Feb 27, 2008)

it has a threads inside the crankshaft. i have a pulley puller, can i do something with that?


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## paulr44 (Oct 14, 2008)

No, afraid not. It would probably damage the rotor - either the lamination stack and or the windings.
The threads are in the end of the rotor for just this purpose. Using any other method is ill advised.
If you don't have a junk weedwhacker, your local OPE shop probably has one they'd part with for free. The Generac kit *may *have an insert that'd work, but you'd surely have to wait as I doubt any local dealer would stock it.


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## critter91 (Feb 27, 2008)

i decided to fix the generator and sell it instead of taking it apart.
do you know where to start with repairing the generator? i start the engine and plug in a drill and i get nothin. i checked all connections, and they are good. but the armature is really dirty and so is the surrounding copper. i already cleaned the commuator so it is shiny copper, but still nothin.


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## paulr44 (Oct 14, 2008)

I have a lot of generator test etc. info. in a previous post that you should find helpful. I used to teach generator theory and repair. See
http://www.hobbytalk.com/bbs1/showthread.php?t=233279


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## critter91 (Feb 27, 2008)

hey i took a 12 volt battery to the brushes and the armeture was being magnetized to one side of the magnets. still i have no power out of it. does it matter if the magnets and armeture are dirty?


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## paulr44 (Oct 14, 2008)

Magnets no, armature slip rings, yes. Magnetic fields pull right through the earth's crust, a little rust sure won't stop the effect. The brushes ride on slip rings - the DC equivalent of commutator bars, but this is AC and they're solid all way around. The contact surface must be clean, and the brushes intact with good spring pressure.
I don't understand what you mean, "was being magnetized to one side of the magnets."
If you manually excite the rotor (armature) through the brushes with 12 volts while it's running, and get no output, then you need to get an ohmmeter and start checking things.
WITH THE UNIT SHUT OFF!!....
I can't give you specs, but...
Disconnect the brush leads, and check the resistance between the two brush terminals.
You should see anywhere from 1 to 10 ohms.
Measure across the slip rings. You should see about 3 to 5 ohms less than through the brushes.
If you have an open (infinity on an analog meter looks like this: ∞ ), then the rotor is N.G.
Measure from a slip ring to ground. You should see infinity. Any reading indicates a short in the rotor, in which case it's N.G.
I can help you with the stator too, but the brushes and rotor are the first step.
Paul


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## critter91 (Feb 27, 2008)

i cleaned the slip rings until the copper was shiny. the brushes have good pressure on the rings.

so you apply the 12 volt battery to the brushes while its running? 
i did it when it was off.

when i said it magnetized to one side i meant the armature was only pulling to a certain part of the field.

also when i got the generator it was missing the shroud that has the pull starter on it and i can see where a wire was broke and someone lazily stripped them and wrapped back together, could that be a problem? it seems to be coming from the magneto.


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