Electrical problem help

Hello,

I'm having some difficulty sorting an electrical problem.

My 73 Commando (Boyer fitted) runs very nicely. I am, however, encountering a problem with the lights on. At low revs the engine dies as you open the throttle. It just about runs if your on the move and I can also just about pull away, it seems like a connection issue maybe?

As the revs go over 3,000 it runs a bit better, but you still feel it's there, turn off the lights and all is well again. It works fine on the pilot light alone. Use of indicators increase the problem.

The problem manifested itself in the garage a month ago - i.e I believe it was Ok when I put it in there a month earlier.

the bike has a capacitor, Zener diode and twin coils on it

Electrics are not my strong point (along with cycle parts and engine), so I was just hoping for some tips, things to check . so far I've checked the battery and cleaned the terminals. I've then just gone around pretty randomly cleaning connections.

Battery was new last year (Bosch standard acid type) . Lights are bright without engine on and brighten when engine revved

Any ideas gratefully received


Rob

Off the top of my head I would say check to see if you have a good ground connection in your headlight shell. It sounds like the charging system is working but maybe a weak battery.
Others will chime in.

Thanks appreciate the idea - Didn't think of headlamp connections so far.

Hi- if you have access to a battery that is certain to be good- either brand new or known to be solid- try swapping that. My Boyer is sensitive to any weakness in the battery and will cut out at the first opportunity. Get it fully charged and keep it on trickle for a few days. +1 on checking the grounds- all of them- and all other connections that could be vibrating. I have also had strange experiences with any loose grounds. That's about the extent of my knowledge on electrics, which I still regard as a mystery... Good luck!

Ta- I'm wondering about that battery now.