hey my friend has a mb and when we start it and give it gas it startes to jerk and bogin out the motor is 66/80 skyhawk cab is nt can anyone tell me what the deal is on his bike please it hasnt been runnin good every sence he got it i have been leavin em behind on my 48cc the float is cuttin off level with the float new gasket on the float bowl oh and now sence its been jerkin 15 is top speed some would let me know what to do would be appr thanx