Originally Posted by SS in Vzla.
DO check your VR.
I once had the "starting issues" you describe and automatically assumed it was a bad battery (cheap Chinese sealed battery than came with the bike from the P.O). I bought a new battery to replace it but it turned out that Chinese battery I took out was not being charged properly, but was still good and gave me about one more year of service (I found this later).
At the moment, I installed a brand new Yuasa and it lasted two days because the VR was bad and fried the battery. The voltage readings I got fluctuated a lot, so it was not easy to diagnose... it would sometimes behave normally (for an extended period of time), it would sometimes go around 11.7v (which is the reason for the Chinese battery not being charged and thus not being able to start the bike on some occasions)... and then, sadly, the voltage went above 16v which happened when I installed the expensive Yuasa (voltage reading which I realized only after the battery was already damaged).
Thanks, I did actually give that a go though. Tested the diodes, and they all came back alright. No problems.
Havent found any info on how to test the regulator portion yet though.