I just finished my 350RX and the main thing that you need to make sure of is if the bottom frame rails were widened to allow the motor to sit lower in the frame. If this was done then you don't need to worry about the negative chain effect. If they haven't had it done then you will notice that when you push down on the rear suspension the chain will become loose instead of tight. You just have to make sure that the chain is tight when the suspension is fully extended and you shouldn't have too many troubles. You also want to make sure that the frame is in good shape and that there are no cracks. Usually around the foot pegs area are where the frame breaks. If they haven't lowered the motor then they have widened the top frame rail and you will need to pull the front plastic to look and the frame. Just make sure the frame and all the parts are in great shape. If you notice any problems talk with person selling the bike and negotiate the price.

 

ok thank you