Hitchcocks Forum

Hi folks just wondering if any body knows if that an old lucas style rotor is capable of loosing it's magnetic charge over the years?

It's possible but unlikely in my experience. The stator usually gives up first. Is it the Connie?

REgards, Mark

Hi calv,



I had a BSA B40 with a Lucas alternator rotor (I guess that counts as Lucas-style!) which had done precisely that. I know it is possible to have magneto magnets re-magnetised, I don't know if anyone offers this service for alternator rotors, though.



A.

Calv
I had similar concerns about the rotor on my 1996 500cc. In fact it was the stator – but I checked the rotor using this comment (from Britcycle.com) and found it A-OK. br

A sheet of the thin plastic used as cover for photocopied reports makes a good gauge - a full length of an A4 page of this film is long enough for a complete strip around the circumference of the rotor (between rotor and stator) and can stay there during tightening to confirm ~10-15thou gap.
Cheers, ChrisD

Hi Calv, rotors can lose their magnetism sometimes. a good, basic test is to see if a rotor can hold its' own weight - ie - you should be able to hang a good one from a spanner for instance. If it drops off, it has lost some magnetism. Regards, Paul.

Common failing with time heat and vibration.


With the Police bikes and High Load demands we used to remagetnize and replace the rotors on a regular basis. All most as often as batteries?


All major Lucas service-centers used to have a 'growler' for remagnetising the rotors.

They can be re-magnetised. I have a re-magger for my old toy train motors, but have used it for many other things. Erasing 'dodgy' stuff off old hardrives can be done quickly and without worry. Also good for telephone bells too!



Stators are more complicated and it would need somebody with experience to do it correctly if it is a bit weak.

Hi guys thanks for all the replies been very helpful. Yes mark the connie. Have renewed stator and think rotor is OK as seems to be charging well

Calvin, glad to hear it! By the way, are you going to the rEOC 40th Birthday/International Rally? Hope to see you and vince there?

REgards, Mark

I know Vince and Tina are all booked up. Just waiting to see if I can get time off work.should be OK.