Where can I get my rotor remagnetised?

[SimonD]

Does anyone know where I can get my rotor remagnetised. I have low voltage output from the generator but one voltage is half the other as it should be. Bike is 350 Strada. Any help appreciated.

[George 350]

Hi Simon,
Our very own 'evguru' Paul Compton can remagnetise flywheels.
Send him a PM to find out more.
I have to ask what you mean by one voltage being half the other though? Each of the yellows to red should have a similar voltage, which should be half of what you get from yellow to yellow.
If the yellow-red values are different it suggests you may have an issue with your stator.
George

[morini_tom]

We will be offering FREE remagnetising on site to everyone who books into the rally 28-30 June.

Another great reason to come!

https://www.morini-riders-club.com/rally2024/index.html

[simonnorthroad]

and if you cant make that VILLIERS SERVICES remagnetises rotors very cheaply by post.

Im sure of this, Ive read it recently, but cant see the service advertised on their website!

sales@villiersservices.co.uk

[SimonD]

Thanks for all your replies.
George, yes the red and either yellow give the same voltage and the yellows give higher voltage but all voltages are are about half what they should be. I will remove the rotor shortly to check the windings.

Have checked the following

Green wire and ground gives 310 ohms
At 6000 revs yellow wires give 30vac
Red and yellow gives 15vac

Does it sound like the rotor magnetism is down?

[SimonD]

This bike has been stood since 1999! Was missing front spark but imported that and it runs lovely just no charge

[SimonD]

Paul remagnetised my rotor but no change. Voltages are still half what they should be a voltage at battery is 12 to 12.5 as revs increase. Any more ideas? Another member posted on this with same problem but there doesn’t seem to be a solution. Any ideas?

[julianharty]

Simon,
firstly, is the Paul you mentioned Paul Compton? He has one of possibly 2 original machines made specifically to magnetise the rotors used on these bikes. (I live fairly close to Paul and he's trained me in using the machine). If it's another Paul, then one option is to either get your rotor to Paul Compton (who's near Luton) or to the Rally where Paul Compton's machine will be for the weekend AFAIK.

Secondly, there's a single coil that provides the voltage for the ignition, that's the one connected to the green wire (and to earth/return). The rest of the coils provide the AC that's used to power the rest of the electrics and charge the battery.

• Brown wire (switched "12V"DC i.e. battery positive voltage) to the red on the regulator to enable the regulator. Can you check whether the red wire has battery voltage on it with the ignition switch turned on, and no voltage with the ignition switch turned off?
• Poor rewiring of the original charging coils on the stator - hard to diagnose without seeing it in person. If you can add photos of the coils it might be possible to distinguish whether the windings look to be appropriate thickness, etc.
• Some or all of those coil windings may be faulty by now. They can be rewound. Some people do this themselves and others farm out the work. As you'll read the companies that provide rewinding services have closed and the quality of work of others may have declined. You might find a company or an individual who's willing to rewind and restore your stator.

Benjy Straw (details in the club magazine ATG), Paul Compton, and George memberlist.php?mode=viewprofile&u=186 are people I particularly trust in terms of their advice; however I don't think any of them rewind coils (these days).

A complementary option is to obtain - ideally - known good items and to diagnose the problems(s) through substitution of your stator, rotor, etc. with known-good items. Paul Compton has various rotors and stators (and morini engines, etc.) available for sale.