when you first start it up there is a ratling noise you can hear it on both sides just as loud when you rev it up nothing changes but after you ride it for a little bit you can barley hear it i just rebuilt it and it did not help it could it be a bad bearing
when i first take off the quad wants to stall but once your going its fine.you have to keep reving it to take off from 1 gear the quad is all stock just like it left the dealer i didnt change anything yet.i also cleaned the carbs