1ls/vtec

I bought a 2013 Ruckus last week for $1k thinking it was a good deal. It is lowered, stretched, fatty tire and gy6 150cc swap. It is having charging issues so I am thinking a bad stator. It also will bog down or even die when I sit on it and the lights will dim out as well. I can't find any pinched lines but this is getting annoying. I can give it a little throttle before I sit on it and then it drives strong the entire time. Any thoughts on what could be going wrong?