OK, so here's the deal. I bought an 81 XS650 Special a few months back that had typical charging system issues. Come to find out the rotor had a short circuit in it and was only reading about .2 ohms. So naturally I replace the rotor. And the problem was fixed, My battery was seeing around 14 volts at 3500 - 4000 rpm. So I'm out for a ride after its fixed and it is running like a top, then I fill it up with fuel and shortly after that It will not rev above 2500 rpm in first gear, shortly after that it will not rev over 2500 in second gear, but once you're up to speed the bike runs great with no hesitation. So then I figure hey I just pressure washed this bike maybe there's some water in the fuel system someplace. So I drained the float bowls and found no water, I then added some sea foam to the fuel thinking maybe I could save tearing into the carbs to fix a small fuel system problem. After that the bike would not rev over 2500 RPM period. So I pull off the left cover and remove one of the brushes for the rotor and the bike runs perfectly! I am a little confused about what is going on here. Maybe when the rotor is magnetized the pickup magnet for the TCI isn't strong enough? I've read some things about putting an earth magnet on the rotor? Are the aftermarket rotors just sub par? I'm new to bikes but have mechanical knowledge. Any help on my issue would be greatly appreciated.