have you taken the baffle out of the exhaust and have u rejetted the carb? it you take the baffle out it will make it bog down in 1st the carb will have the make written on the side and you need to measure the diamiter of the intake. however if the make is mikuni then you are likly to have a VM22 jets are easy to come by i would advise that you buy a few different sizes and see whice one work best for you (that bit applies for ALL makes of carb)