G9 Help for a newbie

Information relating to the Matchless G9 or AJS Model 20 500cc twin
Chris B_LAPSED
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Re: G9 Help for a newbie

Post by Chris B_LAPSED »

Ian thankyou very much for your detailed input. Yes there is a fuse connected to the battery and we changed the fuse thinking that could be at fault but with no luck... the bike will be hopefully be sorted within the next couple weeks and Looking forward to purchasing her. I will keep posted :D
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Rosy
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Re: G9 Help for a newbie

Post by Rosy »

Why not buy it as it is for a reduced price if the seller is willing to do that, then go through the wiring yourself to fix any problem. It's all pretty basic as I have just found out on my G9 and my 350 MS. Work out the cost of having the dynamo overhauled plus a DVR2 (regulator) of which neither may need attention, plus a few parts and see if he/she will sell for less, you also get the satisfaction that you have worked on your bike the way you want it.
bitza
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Re: G9 Help for a newbie

Post by bitza »

Seems like a plan, buy the bike at a deal to suit you , they are easy to rewire , and a DVR 2 regulator costs around £ 48-0 pounds
And can be mounted in the old regulator box this is how I did our g 9 .
Chris B_LAPSED
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Re: G9 Help for a newbie

Post by Chris B_LAPSED »

Thanks for the input all... iv been looking at the DVR2 as probably my first job on the bike. Are these fairly easy to fit? I'll be sticking with the 6v for now.
Groily
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Re: G9 Help for a newbie

Post by Groily »

They're very easy as there are 4 leads, just as on the original. If you want to conceal the thing in the old unit, there's a bit of fettling to do, but none of it difficult.

I'd start with some checks on the dynamo though, and work from there. Is there any output? Easy test is well-documented on here - disconnect the leads at the dynamo, bridge D and F terminals, start engine and see if there are volts dribbling or pouring out from the bridge to earth, using a meter or a bulb - 12v for choice as it will light more easily. I use 21W 12v stoplight bulbs first off as (especially high wattage) headlight bulbs need a bit of current to get them hot enough to light without a battery in circuit. Dynamos are sometimes reluctant to sling out enough current to light a big cold bulb, even at 12v, and rarely light a 6v headlight 'just like that' without pre-warming. If using a meter, you'd expect to see as much as 20v coming out as revs rise, with no loads on an E3L unit

If the dynamo is working, then move up the chain to the regulator to see if there is anything coming out of the 'A' lead from it (which goes to the ammeter and thence to the battery) with the engine running. You should see voltage rising to about 7v, then settling at that level as the regulator does its job. Or a bulb should light and stay lit at constant brightness with rising engine revs. (Bit flickery with no battery to act as a shock absorber.)
If the dyn dynes but there's nowt at A, then the fault is in the wiring to it, or with the regulator. Which is where a DVR2 would come in.

If there is a good solid output on lead A, then the fault is in the wiring upstream to the ammeter, at the ammeter itself, or from it to battery. To eliminate the ammeter as a source of trouble, you could bridge it directly across the terminals on the back and then measure battery voltage with the engine running to see if it rose with revs, or do the bulb thing again off the battery to see if it brightened and stayed bright.

If you don't know of it already, this is a brilliant place for info and practical help - https://www.matchlessclueless.com/elect ... as-dynamo/

I agree that if you are buying the bike, you might as well take it 'as is' with a suitable adjustment. Many of us will never have bought a machine with electrics that workd properly - and even when they seem to, they've often been bodged something horrible. You'll be far better off with a system that a) you now know backwards and b) you know has been put together properly! In terms of costs, DVRs are as bitza says. If the dynamo isn't working, could be anything up to about £250 probably to sort, depending on what's wrong. But unless the armature has suddenly failed, shouldn't be anywhere near that in reality.
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Rosy
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Re: G9 Help for a newbie

Post by Rosy »

Totally agree with the above, I used Matchless Clueless for guidance, my dynamo was overhauled by Paul Dunn & I fitted a DVR2 mounted under seat, left the Reg intact, and kept it at 6v pos. My G9 has LEDs all round super bright lights all 6V, the 350 has std bulbs but has a 6V Cyclon battery that holds a charge forever.
Chris B_LAPSED
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Location: Nottinghamshire

Re: G9 Help for a newbie

Post by Chris B_LAPSED »

Wow thanks everyone. Im certainly looking forward to getting her And will report back as soon as I do. I agree ill go over the things mentioned then ill get a better understand
..... probably followed by lots of questions :lol: in the mean time thanks again for all your greatly received input. :beer:
bitza
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Re: G9 Help for a newbie

Post by bitza »

From memory when you order a D VR 2 there are two versions pos earth or neg earth, I will root through my paperwork and try to dig out the info then post .
More info have a look on Dynamoregulators web site all the gen is there including a schematic for the connections for 12 or 6 volt systems .
Last edited by bitza on Fri Jan 01, 2021 5:58 pm, edited 1 time in total.
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dave16mct
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Re: G9 Help for a newbie

Post by dave16mct »

bitza
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Re: G9 Help for a newbie

Post by bitza »

Cheers Dave,
You must be a mind reader ha ha.
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