1] I have just bought a 1974 basket case of an 850 Commando [MY FIRST Commando] and am surprised to see it has a positive + earth and has RED EARTH LEADS! Is this correct?
2] If correct did the Commando ever go to negative earth?
3] If Commandos did go to negative earth would it be an advantage to do the same during the rebuild?
4] What would I have to do to achieve this?
5] Should I inform the club I now have this bikebike for record purposes?
I hope this is not a silly question.
Many thanks Roger Johnson
Previously roger_johnson w…
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On point 3 only, There is…
On point 3 only,
There is no advantage in changing to negative earth, stick with positive earth and then the standard parts will fit and be as per the circuit diagram.
Tony
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Previously roger_johnson w…
Previously roger_johnson wrote:
1] I have just bought a 1974 basket case of an 850 Commando [MY FIRST Commando] and am surprised to see it has a positive + earth and has RED EARTH LEADS! Is this correct?
2] If correct did the Commando ever go to negative earth?
3] If Commandos did go to negative earth would it be an advantage to do the same during the rebuild?
4] What would I have to do to achieve this?
5] Should I inform the club I now have this bikebike for record purposes?
I hope this is not a silly question.
Many thanks Roger Johnson
All Commandos (from the factory) were positive earth. If you went negative earth you would be able to fit a Sat Nav easier, and maybe your 8 CD disc player! BUt when you sell the bike then the new owner will expect positive earth so finding it Neg might slow up a sale.
Negative earth-if standard ie positive from factory, you would have to find a Neg earth Zener (rocking horse stuff) and fit a modern encapsulated rectifer (original rect is made Positive earth) OR fit a modern regualtor/rectifier. Reverse the 2MC capacitor. rewire the ignition (ie Boyer or RITA) re conect the coils in line with new polarity. Reverse battery. Note a machine that has its polarity reversed without being rewired will end up with the wrong colour earth wire-it will cause confusion do NOT do it. So if you must have negative earth then rewire at the same time.
But no real advantage, especily as your mates in the Norton Owners club come to help you as they refit the battery-the wrong way round!!!
Al Osborn.
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Previously roger_johnson wrote:
Yes
As far as I know they did not. I stand to be corrected and round here, that usually takes very little time.
Views vary on this. See 4]. It doesn't make the bike run any better or faster but some owners (myself included) find it easier to get their head around a negative earth system.
This subject has been discussed before on this site. Try typing 'positive earth' into the Search box on this page and you will find some links to various opinions on the subject.
You don't have to, but it is useful if Members do this. Go to Membership (over on the left) then select My Details & Bikes. You can also make a note there of when your vehicle excise duty and MoT are due.