The generator light.

[chasbmw]

I agree with No 2

If light glows faintly at normal running speeds, I would check brushes for dust and if you have recently changed them, think whether or not the spiral spring is giving enough pressure on the brushes

Charles

[Scoots]

My electrical charging issues began with the volt meter needle bouncing like crazy on everything but very smooth pavement or sitting still at a stop light. I just figured the needle damper had died. Not long afterwards, the GEN light began to glow and would not fade out at higher RPM's.

The problem was twofold: 3 of the rubber mounts on the Diode Board had broken (replaced all 4 rubber mounts with solid mounts - PITA ); the the 3 wires coming off the Generator to the Diode Board had lost insulation coming out from behind the ignition timing cover and were grounding out. Replaced the wires and put a thick covering of ShoeGoo on the timing cover where the wires would rub.

Problem solved, but the whole job was a MAJOR PITA

[Tom H Ca]

What exactly does your gen light do?

Gen light glows very faintly as in waaaaaaaaay less than 1/2 brightness, glow brightens a bit w/ rpm increase to 4k or so at which point it goes dark.

An rpm drop below the "no-glow" threshold results in...a faint glow.
Pretty classic situation based upon my internet research.

I had a similar problem. Light would glow at all RPM.

Pulled tank and checked all connections including the starter relay/cut out. Tapped on the mechanical regulator to see if that made a difference. It did for a second or two. From a bike shop, this would be a regulator failed.
Replaced regulator with solid state BWD and then the above occurred when the engine was cool. As it heated the light glowed at all RPM.

Found a diode board on Ebay cheap. Installed it and everything is just fine. I don't know why the board failed. I always disconnected the ground before removing the front cover. Maybe they just don't last almost 40 years??

[Manfred]

My voltmeter needle often bounces around as if it were possessed.

After I dumped my bike many months ago, it began having trouble starting. One of the many things I did was replace the skinny wires from the diode board to the starter with automotive battery cables and added another ground wire from the battery to the frame near the coils. Made sure the board was mounted securely as well. THAT was a major PIA, but I now have super low resistance and better ground. And an Omega battery that is the tops.

[dougie]

Replaced the wires and put a thick covering of ShoeGoo on the timing cover where the wires would rub.

ShoeGoo Tell me more.

[Scoots]

Replaced the wires and put a thick covering of ShoeGoo on the timing cover where the wires would rub.

ShoeGoo Tell me more.

The 3 broken rubber diode board mounts would allow the diode board to flap & shake when the bike was going down the road. You should have seen my volt meter bouncing from one end of the meter to the other! This shaking pulled on the 3 wires that ran from the generator, behind the ignition timing cover, and back out to the diode board. The pulling on the generator wires, where they came back out from behind the timing cover, wore off about 1/2" of insulation on all 3 wires, and they would ground out on the timing cover. The grounding out had "arced" a very sharp crescent shape on the bottom of the hole that the generator wires had come out of from the timing cover. I ended up filing this "arced area" all smooth, cleaned the area with mineral spirits, then with rubbing alcohol. I then applied a thick coating of ShoeGoo to this cleaned area, including about an 1" down the front & back of the ignition timing cover, so that the replaced generator wires would be laying across the cured ShoeGoo and not be laying on the aluminum of the ignition timing cover ...... just in case the new, solid diode board mounts ever failed.

[dougie]

Thanks Scoots.
I was actually wondering just what is ShoeGoo?

[Scoots]

Thanks Scoots.
I was actually wondering just what is ShoeGoo?

It's a long wearing, thick, goopy stuff that sticks to everything! Sort of like adhesive silicone caulk, but better.


http://en.wikipedia.org/wiki/Shoe_Goo

[dougie]

ShoeGoo
Looks like one of those things that you keep finding more and more uses for, after you buy some.
I love things like that.
Thanks.

[SteveD]

Would seem this thread won't allow an edit.

viewtopic.php?f=1&t=4914

Problem: No GEN light and eventually no charge at all. Bike failed.

Cause: blown GEN bulb.

Solution: easy.