gio rebel t2 rectifier burning up

[jb.]

my kid bought a used gio rebel t2 125 quad...a couple weeks ago the fuse for the starter blew....if i hooked up without fuse, the rectifier would smoke...if i jumped the wire to starter switch to solenoid it would start....after a couple times of doing this the rectifier was smoking bad and melted up....i bought a new rectifier, put it in, and it started just fine.....he took off super happy....5 mins later it died again....i suspect the rectifier, i had a spare cdi, but that wasnt it.....is there something that would cause the rectifier to be failing? thanks!