Sorry for having to introduce myself by having to ask for help! I am a new airhead owner having recently bought a '82 R100RS. The bike is in good condition, no dents, paint was perfect, engine sounds great etc. etc. It had done about 8500km (53000 miles) when I bought it.
Anyway, the guy I bought it from had been plugging the bike and charging it in every day because he didnt use it much. While it was charging the Voltmeter showed about 11 -12v which is low, but he said the battery and everything was fine...mmm...
Well I had done about a week of riding, a lot of it slow , low revving riding when the bike wouldnt start. Just that click click click click click sound. So we check the battery its one of those closed batteries with out easy access. But we got the rubber seal on each of the cells off and found that the battery was completely empty. So we filled the battery up with distilled water and charged it up overnight. The voltmeter showed 13v yay! It also looked like the bike was charging when it got good rpm.
So i continue to ride it but I also notice each time the voltmeter is slowly getting less and less until it went below 11v, and well, I couldnt start my bike. This was four days later. I admit while riding the rpm would often be around 3-4, sometimes over 4rpm, and sometimes id be in slow traffic. Upon closer inspection, when the bike is revving the charging light does not completely go away but remains dimly lit!!
When I checked the voltage across the battery while revving the engine it was about 12. something volts and not increasing very much even with increased rpm. Isnt it supposed to be 14?
So what are my options and what is the most likely culprit? Alternator? Regulator? corrosion? loose wires? If it is corrosion and loose/broken wires where should I look?
What steps do I need to tack to be absolutely sure the battery is charging well? So it wont fail on me again! (planning on long trip...soon...)
Ill also check if the battery is able to keep a charge since it is a bit shady....