I have no proof of this, and no real evidence, beyond the slightly burned wires, but I get the idea that there may be a problem with high resistance, in the stator, or something the stator connects to. I believe if there is a problem, it is an electrical issue. I ride in 120 degree weather in the summer, and the coolant temp gauge gets close to the hot side. I use synthetic 20w50 oil to help protect the engine, but that has no effect on the stator. There is nothing fundamentally wrong with the bullet type connector, as long as it is clean, tight, and connected properly. The wire itself is small enough that it would have more resistance than the connectors. I also don't believe normal heat from riding the bike is hurting the R/R, though internal high resistance in it could be a problem. That is why I never relocated mine. Stators can fail, from no obvious reason, as can any other electrical device. There always IS a reason, but it cannot always be determined. Unlike mechanical parts, electrical parts don't usually leave tell tale signs.
So again, my best guess, and that's all it is, is that output from the stator is encountering abnormally high resistance somewhere in the system. It could be the bullet connectors, but it could be a number of other things as well, or it might be several things combined. That's assuming there is even a problem. What attracted so much attention to the Vulcan 750 stator is how hard it is to replace. Some people have had repeated stator failures in a short time. But, were they using oem stators, or some other brand? And are other brands better or worse than oem? What about rewound oem?
Right now, I will just keep checking those bullet connectors, keep my battery charged, and replace it at the first sign of problems. It's all I know to do. I will replace the stator if it fails, probably with oem or rewound oem.
People have found burned wires on bad stators. Remember, burned wires are a sure sign of high resistance, but it doesn't have to be just where the wires are burned. High resistance further down the line can also cause burned wires closer to the stator, if they are smaller, and normally have higher resistance. Remember, the smaller the wire, the higher the resistance. Adding a bunch of accessories, like running lights or stereo equipment could also cause high resistance, but assuming this stuff is fused, the fuse should blow before damaging the stator. Again that is "should". A lot of things to do with electricity do not always behave as they "should". That is why I have only addressed the one issue I actually found, and have not gone on a wild goose chase trying to find and correct the reason stators are failing. IMO, it would just be an exercise in frustration, and could even make things worse. Jerry.
I am a motorcyclist, NOT a biker.
1997 Vulcan 750, purchased about a week ago
2006 Sportster 1200 Low
2013 Royal Enfield Bullet 500, converted to carb
2001 Yamaha XT225, heavily modified
2004 Honda Rebel 250
1979 Vespa P200E
2002 Vulcan 750 parts bike
1994 Yamaha XT225 parts bike