The bolts that hold the generator to the bracket are 5/16". If a 5/16" bolt is sloppy, then the holes in the generator end frames are worn. In In that case, drill the bracket and the end frame out to 3/8" and don't let the generator get loose again. I like to use Nylock nuts or jam nuts in places like that.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!