Total Motorcycle Community Forums

I made an important (and basic) discovery this weekend. Although I feel stupid, I wanted to post what seems to be the fix for everything related to my problems and finish out this thread. This weekend, while watching a race, I spent a lot of time studying the wiring diagram and tracing out the circuits. I kept noticing a certain part of the diagram but never really understanding why it was pictured the way it was. Then it hit me like a freight train. The diagram shows (physically) two grounds; one to the engine and one to the frame. In all of the troubleshooting I have done, I have checked the frame ground to the wiring and it was always good. I paused the race (DVR's are great!) and went out to investigate. Sure enough, from the frame ground to the negative terminal of the battery was 10 ohms of resistance. It never really sunk in that the battery was isolated from the frame and the engine is isolated from the frame with rubber mounts. Actually, the resistance reading would start out at 6 ohms and slowly rise to 10 so it obvious that the frame ground was getting its ground through some electrical component. I installed a wire from the frame to the battery and took the bike out for a drive. All of the electrical problems were gone and its performance was 10X better that its ever been. Now I still left the tach off for this ride because I was in the middle of troubleshooting. It still could be a problem in the tach but I am 99% confident that the problem was a bad frame ground to batters connection. This just proves that you can't ever overlook the basics. Thanks for everyone's help. Sean.

Sev, the charging voltage seems to be between 13-14 volts at all RPM's. My meter is analog and is had to see a real difference between idle and 5K RPM. The meter fluctuated slightly from just above 13V at idle to just below 14V at 5K RPM.

I didn't read the whole thread so not sure what all is going on but, below 14 volts is a little low for 5k rpms. Should be closer to 14.5 volts or so.