commando charging q

[dunboyneroadracing]

ive a mark 3 commando , while testing the charging system i got irratic readings on the multimeter, holding at 12v (battery was charged ) ,with small revs it seemed to drop in power but when given a bigger rev and revs were dying the volts went up to near 13 volts, im presuming this is wrong an am putting off heading to a show tommorow over it, shows 50 miles of a journey so im weary that it will get there and home,

bike had been lying up for 5+ years .
any input?

[L.A.B.]

Presuming your MkIII still has its 180W RM23 single phase alternator and double Zener diode charging system and it is still positive earth?

Then:

Disconnect the negative wire from the battery, and connect a DC ammeter between the battery terminal and the battery negative lead (black ammeter wire goes to the battery terminal).

Start the engine, and with the lights switched on, there should be a minimum current reading of 0.5A at 3,000 RPM, or 3,500 RPM if it has a halogen headlamp bulb.  

[dunboyneroadracing]

thanks for that, got it sorted , sweet bike to ride , lights aint great but i think its an american spec lense.
any reccomendations where to look for parts, ill be needing indicators, right side handlebar switch (on off for lights buttons broke), lights for dash or even a dash itself ,the lense and a few other bits .

[L.A.B.]

any reccomendations where to look for parts, ill be needing indicators, right side handlebar switch (on off for lights buttons broke), lights for dash or even a dash itself ,the lense and a few other bits .

Mick Hemmings: http://www.norton.norvil.net/mickh.htm (no web shop, but my 1st choice for service)
RGM Motors: http://www.rgmmotors.co.uk/
Norvil: http://www.norvilmotorcycle.co.uk/
Andover Norton: http://www.nortonmotors.de/ANIL/Norton%20Website/norton/parts-list.php?Model=n850_e