help. kostof problem

["1sclunn" <1sclunn@msn.com>]

so the other day I'm driving a 30 mile trip I do once a week and I'm in 3
gear going 60 with a 240 v set up t- rex 11"kostof when the thing dies.
Pull over and look under the hood .  I give it some gas by hand to see and
get low rmp and the motor is shacking a lot .not enough power to move the
car at all .Like some thing is bound up .I first though its a bearing but
today when I take the motor out every thing looks fine . when I spin the
motor over by hand It turns real nice no noise or grabbing . I hook a 12v
battery to it and it truns veary slow and shacks like its fighting its self
. As soon as I remove the wire it smothes out . connect it and it starts to
shake. the armiture looks ok ,I don't realy know what I'm looking for .
This has a home made hub that holds the flywheel and It wasn't one of my
better ones I think it was .012 out of round and when I went to the 240
volts for 120 volts i noticed that at certin high  rpm I got a vibration
that went away as the rpm went up .  maybe this shook somthing lose ?