Just got my 1969 ct90 registered, and after the first day of driving it on the street, its started giving me some battery charging issues. This is strange because I have put about 400 miles on it along trails near home with no issues. Maybe higher sustained speeds broke or burnt something that had been fine before?
Description of problem:
After charging a new SLA battery on a trickle charger throughout the night, showing a voltage of 6.51 vdc before installation, the bike starts up great, runs strong. However, after only a few miles the bike sputters and dies, all the lights go very dim, and I cannot get it to start. Switching to a fresh battery gets me a few more miles.
I have three different, 6v 4.5 aH SLA batteries, 2 of which are brand new. I get the same results whether I am using only a single battery, or if I am using 2 in parallel setup. Also I have a wet battery with the same results.
I have installed the radioshack rectifier, all connections soldered and heat-shrinked. This upgrade was done hundreds of miles before the problem arose however, and I do not suspect it as the problem.
Testing the red/white wire coming out of the battery gets me 6.5 volts with fresh battery and bike not running.
Testing the red/white wire coming out of the battery gets me 6.15 volts with fresh battery and bike running, revving the engine alot yields more like 6.2
Testing continuity of stator coil wires gives correct result based on diagnostic instructions from 1977 shop manual.
Testing AC output from these 3 wires however, seems to be the problem perhaps?
White wire output = 16 --> 30+ vAC depending on rpm
Yellow wire output = 3.5 vAC static
Pink wire output = 0 vAC static, 6.15vDC raises to 6.2 with throttle
Results at rectifier:
Yellow wire input: 3.5 vAC static
Pink wire input: 0 vAC static
Red/White wire output: 6.15-6.2 vDC, 0 vAC
What other tests can I perform, or is this conclusive? What does it mean? Is my pink wire bad from the stator perhaps? How can I fix this if so? Maybe I am testing incorrectly?