Motorcycle Repair: charging system, honda sl125, pink wire

Question
Hello, I have a Honda SL125 S0 1970 motor that I have mounted on a three wheeler and I have had it running and it runs fine, however; it doesnt run for a very long time I figured it is the charging system because if i charge my battery back up it will run on the first kick and drive for a little while. My battery shows to be drained after it dies because it wont start again. i was wondering how do I check to see if the ac generator is producing enough juice and is there a way I can check to see if it is bad. I hooked up the wires correctly I believe I followed the schematics from the website on your other question answers. I ran a wire from the ac generator to an ac to dc device and to the battery to charge it. If you have any advice I would greatly appreciate it. Thank You.

Answer
Stephen, The charging systems are all pretty sound on these bikes, other than the rectifiers. If all of your wiring connections are correct, as shown in the wiring diagrams, probably the rectifier is bad or not grounded correctly. You have to run both the pink wire and the yellow wire to the rectifier to keep the battery charged. If you are going to run lights, then all three (add white) have to be wired in correctly.

These engines have battery-powered ignitions, as you have discovered. With only 6v to start with, it doesn't take long to run it low enough to kill the sparks to the coil. Check your charging system output with a fully-charged battery to start with, then watch both voltage and current to determine if it is getting fully charged again, while running.

Bill Silver