CB 500 loss of charge

[Charliecharlcomb]

I wonder if anyone can help me with this niggling problem.

If I start with a fully charged battery (the bike is sadly underused and only comes out a few times a year), all seems fine. Horn, electric start, indicators etc. all work perfectly. However, after a few miles, I notice that if I have the lights on and pull up at a junction, the engine will die. If I turn the lights off and kick start it (the electric start won't work at this stage) it starts fine, but the horn, indicators etc won't work. In fact, if I use the brake light when it is ticking over it will die too. When I return home the battery is flat and needs recharging.

It may be that the battery is faulty (I have had to change it a few times in the past when it hasn't been used for say 12 months), or could it be a dry connection somewhere?

I did fit a new alternator cover a while ago, I wonder if I have dislodged something?
Is there an easy way to test that the bike is charging so perhaps I could fix it by changing the battery or does anyone have any ideas what it might be?

Electrics are a bit of a black art to me so I'm stumped.

Any sensible suggestions would be welcome, especially as I have an MOT booked for tomorrow!

Cheers

[Bryanj]

There is a full charging test procedure in the manual and all you need is a multimeter but do not rely on the resistance readings on a cheap one. Probably the regulator points stuck or dirty but easier to fit replacement if you dont have testing kit

[Charliecharlcomb]

I've got the Haynes manual and there seems to be a procedure there so I'll try to get my hands on a multimeter and test it. No details on the regulator though. Can they be fixed, are replacements easy to get?

Cheers

[matthewmosse]

I had one altinator cover and assosiated windings that gave me these problems, being a bit numptyish when it comes to electricals I just swapped for another and the problem resolved so decided that the windings were dud on that cover, then a few years later got it mixed up into my other spares and wound up re fitting it, problem returned. On mine it was ok for about 20 - 30 miles of moderately fast roads with my lights on, then misfores and cutting out, plus dim lights. Town riding it would have been much shorter ranged. I regarded it as good training at not using the brakes and keeping the revs up, 3.5k on the revs and it just about coped with demand as long as the lights were off most of the time, good thing it was moonlight on the adventures with that charging issue, I was covering a lot of miles on the bike at the time.

[Charliecharlcomb]

I'm also investigating any snagging of the cables by the alternator cover.