FIXED: Starting Problem, starter spins but crankshaft doesnt turn?

[3imo]

http://www.bikebandit.com/partsbandit/showschematic~dept_id~710217.asp

look at item 8.  The one attached to the bolt(node) is the + bushing/brush  The other Is your - bushing and should be grounded to the chassis somehow.

from the diagram it looks like it would be impossible to reverse these bushings, because of the shape of the plate they are on.  I don't have a motor in front of me to make any real determination.  But I would guess they somehow swapped these bushings.

I believe that is the only way they could have reversed the polarity of the motor to make it turn the WRONG way with the RIGHT connection.

Again, just a guess.   Why don't you split your motor apart and rebuild it according to this diagram. ( I believe Clymers has a better diagram and maybe a how too.)

[The Buddha]

On my virago I believe I had a ring gear and there were 2 idlers fitted on to a plate. the ring gear was the one that was attached to the nose, the idlers were meshing into the starters gear inside the starter assy. If that was installed reversed maybe it can create this problem.
Cool.
Srinath.

[68gtcs]

Looking at my starter there are etched in tick marks, they look like this l l

One set is on the main cylinder sleeve where it makes contact with front side end casing (the side adjacent to the output gear), the other set of marks are on the opposite end of the starter, on the molded butt end cap.  Are these supposed to be adjacent to each other?  If so mine are not.  Any way this could effect the rotation?

[Jughead]

Brushes are worn causing it to turn Backwards.

[3imo]

Brushes are worn causing it to turn Backwards.

Please xplain how that would cause it to turn backwards.

[Jughead]

Just Seen it happen Before in Power tools. Can't Explain How unless it only Starts in the Direction of less Resistance.

[3imo]

that actually makes sense.

When the motor turns, the armature passes through where the poles of the electromagnet flip. Because of the flip, the north pole of the electromagnet is always above the axle so it can repel the field magnet's north pole and attract the field magnet's south pole.

If the brushes were worn down too much it might be possible to have a motor that turns backwards.  BUT I think the real symptom would be a motor that would start in both directions not just one.

Wouldn't a high torgue DC motor like this have something that would prevent it from starting to turn in the wrong direction? I know small fan motors have .......damnit I don't remember the name, anyway
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68gtcs - how do your brushes look?

[sledge]

The only way to reverse direction of a DC series- wound motor, such as a starter motor is to reverse the current flow through the armature relative to the field winding. Same rule applies to shunt, and compound wound machines. Tick marks indicate its been taken apart at some stage. Highly possible something has been incorrectly connected inside when it was dismantled. Take it to an auto-electrician and explain the fault or find a replacement at a breakers. Worn brushes do not lead to a reversal in direction, either with any type of DC motor or the AC Universal type used in power tools. To reverse direction you must reverse current flow.

[starwalt]

I PM'd you, but had another thought.

First the PM thought.
Sledge is right, the current would have to be reversed...as in the battery connected backward. No withstanding the charging/electrics issues involved -- I don't know that the bike would run like that -- the starter motor would turn backward.

Second thought -- inspired by Sledge -- Someone may have reassembled the starter housing with the magnets backward.

This would reverse the poles....any lights coming on now?

If you can read the label on the motor and the gear shaft is at the top, this is correct.
The || marks he mentions earlier DO NOT align up. The marks on the magnet housing are at the output gear end. The marks on the brush end are on the opposite end.

Now if someone managed to remove the magnets...you know just for fun...and put them in wrong, then the || marks would be correct, but the thing would still run backward.

If you have a Haynes manual, page 8-18 shows the || marks (gray & white pics).

I see another photo oppportunity coming.

[sledge]

Starwalt??
I am assuming its a series-motor but after some thought  and your comments I am not 100% certain. Does the starter motor have a permanent field? i.e is the field formed by permanent magnets surrounding the armature. Or is the field formed by wound coils energised at the same time as the armature.?

[sledge]

If the motor has been apart, then reasseambled with the brushgear 180deg out it will also cause the motor to reverse. In effect the polararity of the brushboxes will have transposed and current flow through the armature will have been reveresed. Check the indexing marks carefully, see if they will match up if the endplate is moved through 180deg.

[68gtcs]

Ok, here is the verdict......

I took the starter apart and turned the starter sleeve around 1/2 way, meaning that the end that was near the output shaft is now adjacent to the butt or the starter.  I reassembled the starter, hit it with 12v and it turned in the other direction (counterclockwise), which is what I need!!

I put the starter back in the bike, installed the intermediate gear and the starter gear engaged the crankshaft.

I have not started the bike yet, I have cranked on it just slightly because I'm waiting for the RTV to completely dry.  Tomorrow I'll fill it with oil and hopefully take it for a spin.

I'll let you know how it goes.

Thanks for everyone's help.

[sledge]

Sorted

[rangerbrown]

wow a lot of work but sweet ending

[68gtcs]

Its fixed, runs great!!   Thanks to everyone for their help, good group here!

[3imo]

 

Have some kool-aide. 

[starwalt]

Its fixed, runs great!!   Thanks to everyone for their help, good group here!

That's what we are here for...that and the chicks...chicks dig guys (or gals if they are oriented that way) that can fix stuff.

Sledge's comments triggered the sleeve/magnet idea. I give him the credit for the idea genesis.
Who'd have thought anyone would assemble the motor magnet sleeve/housing backward?
Man, what a great prank to pull on someone! 

Sledge - Yep, the GS starter motor is PM device. You are correct about reversing the field connection on a field wound motor. It will reverse the direction. The stock 89 + starter motor cannot have the brush mount reversed either. The brush positive lead is attached to the connection stud and is insulated from the housing. The brush negative lead is attached to the brush plate...attached to the housing end piece.

That reminds me...on some of the starters I have purchased via ebay, the PO has messed it up because they proceeded to turn the positive lead stud without holding the jam nut properly. To do this, a thin wrench may be required beneath the electrical lug. The top nut, electrical lug, and jam nut must be removed to remove the brush mounting plate correctly.

This does not address the fun of trying to assemble the motor without proper brush removal.

And don't forget to reinstall the brushes in the correct wear  orientation either. If not, the worn edges can get caught in the spaces in the armature contact.

Details, details, details....

[sledge]

starwalt?
I am not taking all the kudos for this one......call it 50/50