Valeo starter motor again

[carbold]

Bike was struggling to start up, it got progressively worse, then just the lonely solenoid click.
Relay is tested and working fine. I removed the starter motor and ran it straight off the battery: the bendix comes out, but no rotation. Will start if I initiate the spin by hand, but drains the battery quickly.
The motor spins when connected to the car battery, but it doesn't on the bike battery (higher CCA in car battery I guess). Bike battery is new and fully charged (13.8 volts).
So I opened it up thinking the usual magnets desbond, but these new Valeos have a metal cage so the magnets are fine. Brushes look fine to me.
However I noticed two dents (see pics), there is no sign of rubbing against the magnets though. Looks like they are on purpose, maybe to balance the rotor?
I suppose the bushes worn out and the core is hitting the magnets and getting stuck?
Any pointers from our wise members?

 

[Pete.]

Those cutouts are deliberate. they are done to balance the rotor after it's wound and potted.

 

[Ian J Hartley]

First off, those machined indentations are to balance the rotor.

Secondly, you never said, when you get it to spin. Does it spin as it should, ie at full speed and will try to take off if not clamped down.

it’s probably stating the obvious that it’s most likely that you have a fault somewhere in the windings, which is causing the rotor be sluggish to turn. The fact that it drains the battery quickly points to a short across the windings somewhere.

On the original Valeo starter motors, when the grease plate covering the planetary gear housing used to come a drift and short out the windings, it would give very similar symptoms. No rotation, clock resetting ( short across battery), sluggish rotation, grinding noise.

Cleaning the electrical contact areas and detailed visual check with continuity checks may throw up something.

It’s interesting that your starter motor has 4 brushes. Whereas the earlier ones only have 2. So check that there isn’t accidental electrical contact somewhere in the brush pack block.

 

[carbold]

Thanks all. I cleaned everything I could, cleaned all the contacts with metal brush and contact cleaner etc. I did find some grease around the magnets coming from the planetary....And yes, when it turns it's very slow, nowhere near the speed it should be...
I opened up and cleaned the brush pack, it was a pain to reassemble with those 4 springs. All soldering was good, nothing suspicious there.
It's all pointing to dodgy windings and we are heading to a new starter motor I'm afraid. Thinking to get the Arrowhead from MotorWorks.

 

[Ian J Hartley]

A poor earth connection on the bike could cause a starter motor problem, (poor current flow) but if you have isolated the starter motor from the bike and it’s still faulty then you can effectively rule that out.

 

[carbold]

A poor earth connection on the bike could cause a starter motor problem, (poor current flow) but if you have isolated the starter motor from the bike and it’s still faulty then you can effectively rule that out.

One of the *many* things I tried is connecting the motor straight to the battery terminal, and still faulty so I'd rule this out

 

[Pete.]

I notice that the metal slinger is missing from your photos. Mine was shorting out the rotor windings.

Have you read this post by myself a short while ago?

Starter Strip

Been using one of those the past 18 months with no issues.

www.ukgser.com

 

[carbold]

I notice that the metal slinger is missing from your photos. Mine was shorting out the rotor windings.

Have you read this post by myself a short while ago?

Starter Strip

Been using one of those the past 18 months with no issues.

www.ukgser.com

Thanks, I'll have a look at this, maybe try and run it without the disk to check

 

[carbold]

So I had a look at this, the slinger is fine, no signs of shorting there, and so is the winding in that location. I ran it without the slinger and still no joy.
I'm going to do a final check on the battery to test the cranking amps (waiting for the gadget to arrive), then if battery OK I'll order a new motor on Monday.

 

[carbold]

Just to close this loop, I got the Arrowhead motor from MotorWorks and it's all fine now. I hope it lasts! Thanks everybody