Hi, my sons does the same thing. He got his for Christmas last year so the warrenty is out. I pulled the carb and found no trash or plugged jets. Put carb back on cranked and idled fine hit the gas the first 4 or 5 times and it bogged/died then it started taking the throttle and ran fine for the next couple of trips then same thing happened again. I talked to service dept, at local dealership and they said there had been no wide spread problems, and didnt really have a solution. Hope you find something out and post back.
Thanks,
JC