replacement rectifier recommendations

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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replacement rectifier recommendations

Postby Robert Livingston » Thu Jan 10, 2019 6:32 am

Hello: I am working on replacing the wiring harness for a '67 G80 CS and am looking for recommendations for a 6 volt replacement rectifier. (Finding usable specs on these Chinese scooter rectifiers is nearly impossible. What is the heck is the conversion factor between a 150cc GY6 and a 500cc Matchless?) Secondly, what should I expect for alternator output at idle? Thanks again for your help.

Bob

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Re: replacement rectifier recommendations

Postby spookefoote1956 » Thu Jan 10, 2019 6:41 am

DVR2 brilliant
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Re: replacement rectifier recommendations

Postby Groily » Thu Jan 10, 2019 7:23 am

On a dynamo, yes! But not here.
For an alternator set-up, I favour using a combined regulator/rectifier unit such as Al Osborne's A Reg 1 (12v) or A Reg 6 (6 volt).
Output at idle depends what alternator you have (and doesn't mean a whole lot unless loads are being applied for testing). But the output at revs should be about 90 watts if it's an original. A more modern replacement will provide 110W+, maybe 200W depending on what has been fitted.
Just me, but I'd go for a replacement alternator with welded rotor etc, 12v, A Reg 1, Podtronics unit or even a Boyer Power Box with a capacitor in there if you want to be able to run battery-free. This offers the simplest possible wiring as you make up a harness, with minimum points of failure. Works well for me on several bikes.

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Re: replacement rectifier recommendations

Postby Mick D » Thu Jan 10, 2019 8:13 am

Hi

I went with tradition and used a Lucas 6V Rectifier / Regulator from AMC Classic, it's slightly smaller than the original but looks the part.

Regards Mick

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Re: replacement rectifier recommendations

Postby ajscomboman » Thu Jan 10, 2019 11:49 am

Mick D wrote:Hi

I went with tradition and used a Lucas 6V Rectifier / Regulator from AMC Classic, it's slightly smaller than the original but looks the part.

Regards Mick


Funny old game this, when we looked at stocking 6V regulator/rectifiers it was deemed most people would want to upgrade to 12v at the same time as bulbs are easier to get hold off at any motor factors or garages.

I must admit a conversion is something I've done if any part of the alternator has let me down, but we're open to suggestions if the membership think it's worthwhile stocking 6v alternatives.

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Re: replacement rectifier recommendations

Postby spookefoote1956 » Thu Jan 10, 2019 12:40 pm

Groily wrote:On a dynamo, yes! But not here.
For an alternator set-up, I favour using a combined regulator/rectifier unit such as Al Osborne's A Reg 1 (12v) or A Reg 6 (6 volt).
Output at idle depends what alternator you have (and doesn't mean a whole lot unless loads are being applied for testing). But the output at revs should be about 90 watts if it's an original. A more modern replacement will provide 110W+, maybe 200W depending on what has been fitted.
Just me, but I'd go for a replacement alternator with welded rotor etc, 12v, A Reg 1, Podtronics unit or even a Boyer Power Box with a capacitor in there if you want to be able to run battery-free. This offers the simplest possible wiring as you make up a harness, with minimum points of failure. Works well for me on several bikes.


Apologies, not used to modern bikes ....... unless they're attached to the front of an old one!
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Re: replacement rectifier recommendations

Postby Mick D » Thu Jan 10, 2019 1:42 pm

ajscomboman wrote:Funny old game this, when we looked at stocking 6V regulator/rectifiers it was deemed most people would want to upgrade to 12v at the same time as bulbs are easier to get hold off at any motor factors or garages.


Hi

As a fair weather rider I don't tend to use lights other than to draw attention to myself, in mid summer it gets dark around 10:30pm and dawn is around 03:30 am here :)

My restorations are aimed at returning the bike to a condition close to that in which it left the factory so I keep to 6V, wiring sizes and colours etc. where appropriate, others will have differing aims.

Should the club stock 6V regulator / rectifiers? They are quite easily sourced elsewhere so maybe the funds would be better spent on Matchless / AJS specific spares.

Regards Mick

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Re: replacement rectifier recommendations

Postby Expat » Thu Jan 10, 2019 3:29 pm

Good point Mick.

Once a few dodgy connections had been sorted and an A Reg 6 fitted along with led bulbs, I’m more than happy now to stick with the 6 volt system.

:)
Keep shiny side up.

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