I know on mine the stator got some metal chunks in it and made it shut off randomly. Also the ground on the starter got loose, which caused my battery to short out. I also figured out that it doesn't like to run with a low battery, It screws up the fuel pump. because every time you give it more throttle, the generator gives the pump more voltage. So it's pulsing as you are riding. Make sure you keep your battery charged.
And the front diff fluid. Why did you put it in? I've been running mine without fluid in the front diff ever since I bought it. It makes it a solid front axle. Last time I took it to a shop they filled the front diff. The first day I rode it, I got stuck so bad, I had to pull it out with my winch. After that I never put fluid in the front diff again. I just put a couple droplets in it to keep it from getting over heated.
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