AJS & Matchless Owners Club

Unfortunately, I don't think there's a BrightSpark EasyCap for alternators? Great on the SR1 magneto.

Perhaps Groilly will put me right.

Johnny B

There are options in fact Johnny B.
I don't want to fall foul of forum advertising rules, but one of the Universal EasyCap boards we make would fit in the space available on a G5. There are many hundreds fitted on battery and coil systems, whether under dizzy caps or next to (or remote from even) contact breakers in timing covers. Would always recommend the 220nF version with battery & coil systems.
Quite easy to do, but probably need drilling and /or soldering for the screw to earth and the live wire respectively, and will always need some shaping to get the board to a suitable shape (which is dead easy to do.). Not polarity sensitive, so can go any way round.
Plenty of examples to look at here if interested: http://www.brightsparkmagnetos.com/easy ... /index.htm

dodger wrote:You might want to look at the auto advance and retard mechanism, they are nearly always worn out and replacements are not available, electronic ignition is the way to go.

You can repair them. I did mine and it works fine. They usually wear to a point where the rotors end up leaning forward because of too much space between the rotor and the back plate so just remove the circlip and fit a small washer onto the circlip shaft to allow just enough space for the circlip to go back into the groove and or course to allow free movement of the rotors. This will take up the space and stop the rotors from leaning forward give the moving parts some light grease and all sorted. Maybe changing the springs would be a good idea as well, the club does stock those. Did mine years ago and it is still fine

Well I did use pretty much any condensor Clanger, new for a CB500. There is good spark and I've checked timing again and again A/R weights open 1/4" BTDC. But all I'm getting is very occasional spit back thro carb. Even tried running down a hill...nothing. Before confirmed u/s condensor the bike was running. I think a fresh attack tomorrow, any test tips?

Sent from my SM-T580 using Tapatalk

vigo wrote:any test tips?

Hi

I'd be tempted to strip the carb first and confirm all the jets and galleries are clear, then re-set the carb to its basic settings and see how/if it goes.

The other possibility is a stuck ATD, did it open and close easily when you were timing the bike?

Regards Mick

As an initial test, turn the engine until the points are closed. Connect a spare spark plug to the HT lead (and earth the body).
Switch the ignition on and manually open the points with an insulated screwdriver.

You should see a small spark at the points and a nice fat, blue spark at the spark plug. If that's the case, you may have fuel problems so strip & clean the carb.
If the spark at the plug is thin/weak/yellow, then something is probably wrong on the ignition side.

Good luck!

Didn't need to spend much time investigating. Started with the ignition and was getting a nice spark which then started to degrade in quality and finally, no spark at all. I was thinking during test the plug earth wasn't always good, sometimes I could here the spark across points (no splatter) then nothing. I have measured volts at the points (6v) and the ameter shows a discharge.
Surely has to be the coil which does look like it's seen some service?

Yes, it sounds like the coil is failing. Only way to be certain is to try another...

This bike is so simple it's got me confused. I now have new battery, plug, ht lead, condenser and coil. But no spark. Plug to earth with ign on open and close points, no spark across points at all. There is 6v at the points with 30ohm resistance across points when closed (is that right?) Or are suprisingly expensive points my next purchase? The €39 coil has 10kohms centre post and about 1.5 across + -.
The €15 condenser is for a honda cb500 the values I haven't yet measured but 12v honda 6v G5 should this make a difference? . I'm stuck here in Germany and stuff mailed from uk last time took 17days hence non amc spares.
I'm being pulled towards the new condenser.
Any advice gents?

vigo wrote:There is 6v at the points with 30ohm resistance across points when closed (is that right?)

Sounds like dirty or faulty points to me.
I'm no leccy expert but with the points closed surely there shouldn't be any resistance between them and the meter reading should be just the same as if the two meter probes were touched together?