It could be the tps or the tss. TPS is on the throttle bodies and works to advance the timing by sending the throttle position to the ecu. The TSS is the little pin switch on the your bars at the thumb flipper. That one you can unplug and see if that helps. It is there as a safty switch in case your throttle cable freezes, this switch is the most likely problem. The tps needs to be tested using a special meter that feeds 5 volts to the unit and measures output at varying throttle positions.