Alternator rotor

I’m posting this here as the "





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issues" section no longer seems to take new posts.I’ve not refitted the alternator to my V7Sport yet because I need to do something to the rotor.Electrically,
it checks out fine. However the windings are wrapped in some sort of
paper and lacquered. This is coming apart and lacquer is missing in
places. Does anyone know if there is something I can use to stick it all
back together? I suspect that, if I leave it, movement of the unsecured windings will cause them to fail. Not easy to get a photo but this is what I’m talking about.It’s
still the old low output alternator that the bike was built with but
this has always worked well enough. When I wire the bike I’ll include
the extra cable so I can update to the later type if I want.

would change that for a new part

I can clean and revarnish them if any help

Agree with posts above, swap or refurb. It’s a charge fault waiting to happen
All the best

Not new but refurb.Ray or West Country Windings.If you go for the latter it will come back better than new (I am told) as they wind it tighter.

+1 West Country Windings

Love it! West Country Windings are in Harlow, Essex!

They used to be in the Plymouth area, I have used them a few times over the years and they do know their stuff.


Like Sawbridgeworth Motorcycles, also actually in Harlow. (what a coincidence.)

AND, Ongar M/cycles moved to Dunmow.
Mike H2014-06-09 16:34:43

Well people, As I’m a tight wad, I’m going to clean it up, lacquer it with some stuff I’ve found on the net and put it in the vacuum packer.The windings are still tight and hopefully a relacquer will be enough to save things. If not, I can get a second hand one for £24 from Gutsibits.

whem you varnish it have it on a bar and spin it round that way less chance of it pooling and throwing out of balance

Think a bit of misleading myth type stuff creeping in here, if electrical DC resistance is correct, and the insulating varnish on all wires OK (no bare copper), then OK.


My myth ( Thoughts) is coming from basics in rewinding motors what has gone on this one is the insulation bindings that was put on the coil at makers it is not detrimental to the operation of the unit as long as all the coil windings are varnished as a solid lump. the copper comes double varnished as standard it is then wound onto some form of former and then the when assembled on the rotor it is all varnished to keep all the copper windings from vibrating and more importantly all the voltage used will be forcing the copper wires apart causing the original insulation to rub of with the friction that way its all as one lump especially as spinning at 4000 revs etc All re-varnishing will do is fill in any surface holes and added insulation against any metal part and generally secure the windings better

Yes Ray, that was my thinking. The coils are all nicely together in one lump but some of the lacquer used to encapsulate the lot has come off. Probably more to do with bad storage than anything else. I want to just make sure that everything can withstand the spinning and vibration and not deteriorate any further. A re-lacquer should be good enough according to the local electro diesel place.Good idea about keeping the rotor balanced as well.
v7john2014-06-10 19:15:40

Still think it’s a case of ‘inventing a problem’, but I’m willing to be proved wrong.

40 years a electric motor winder and belt and braces is what i go for

Harlow is in the West of Essex!

Talking of alternators, on my cali ev if it was left out in heavy rain the charge light would come on but go out after about 10 miles (water interferance somewhere?) however, two nights ago we had heavy rain, light on the next morning as usual. BUT. It went on and off a few times as revs rose and fell and is now constantly on. Bike is running fine. Any ideas where to start.

Having a read of this is a good place to start.

Full of helpful advice on charging issues or does your have a newer generation charging system than the older Bosch systems fitted in the late 70’s, early 80’s.?Don-Spada2014-06-13 14:57:52

Extensive, but very usefull. Thank you don-spada