Headlight switch - ignition woes

[old_chopper]

Wifes bike is an '83 GS300. We painted it over the winter and I got it out to blow the dust off. Headed up the street and it started stumbling like it was out of gas. Having been the fool before I checked the gas first, half tank. I drained the bowls to make sure there was fresh gas in each and took off again. Same result. Hooked up a drain hose and had good flow from the petcock, drained the tank and added fresh. Short spin and same result, stumbling, won't rev, but idles fine. Same result with the cap off to test the vent. To make the long story short, for some reason I switched the headlight to high beam and it ran fine. I found I can make it stumble messing with the high/low beam switch. I haven't dug into it more yet but was wondering if this sounded familiar to anyone. My 550 ran 1 lead directly from the charging system to the headlight, if this is the same perhaps the interruption in the charging system is causing a low voltage miss? Battery cranks good and stays on a tender but hasn't been load tested.

[tom203]

Yes, the 81 and earlier bikes had one stator loop thru headlight on/off switch. Your 83 might have the wiring running up there but it shouldn't do anything- it's not switched off. Going from high to low beam ain't much juice difference (assuming both filaments are good), so something is amiss. Better break out the multimeter and test your charging system to ensure a decent output.Also with bike not running, but key on, switch between high/low to see if you get any voltage pulses- maybe bad wire in switch?

[old_chopper]

I found a single wire connector in the head light bucket that had been hot and not completely plugged together. I cleaned it. Also found a small wire on the solenoid that wasn't pushed on very good. It's one of the two small wires with the push on connector. I cleaned several other plugs and the problem is gone. I am not certain which fault was causing the problem but it runs great now regardless of the switch setting.

[Killer2600]

I found a single wire connector in the head light bucket that had been hot and not completely plugged together. I cleaned it. Also found a small wire on the solenoid that wasn't pushed on very good. It's one of the two small wires with the push on connector. I cleaned several other plugs and the problem is gone. I am not certain which fault was causing the problem but it runs great now regardless of the switch setting.

What solenoid is this? I can only think of one solenoid on these bikes, the starter solenoid.

[OldVet66]

I would dissemble the switch clean it and coat the contacts with dielectric compound. It seems the switch was part of the problem with the tenuous connections, before you fixed that problem. The grease they used in the switches hardens up and the contacts get a green patina on them. You might want to get a very clear plastic bag to work in, there are springs and small irreplaceable parts in there that are easily lost.