I normally donĀ“t work on these types of bikes i just mainly do off road mx bikes But this could maybe help u out.Try adjusting your valves i just had a customer come in with the same bike and year etc. I measured out his valves and they where way to tight the factory specs are : Intake is between .08-.12 Exhaust is between .16-.20 try to adjust them so they are in the middle.It made a big difference on his. Good luck