G'day scooter65, I don't know about the 500, but on the smaller scoots, for the rattling, I would be checking the variator ramp plate slide bushes, if they are worn/gone the two halves of the variator will be knocking together making a fairly loud rattling noise. As for the taking off in "too high a gear" I would be checking the torque driver spring, if it has weakened it won't offer enough resistance against the variator weights. Not saying these are the problems, just what I would be checking.