I have Honda CD-70 2016. 18000 km run. When during running on road in 4th gear at speed of 80km when there is slightly height on road then the speed drops to 70 km if there is flyover then the speed decreases to 60 km. I have changed my clutch plates of my bike but the problem is still exist. When i travel about 50 km distance its pick is more down and it can not pick its speed more than 60 to 70 km. Plz suggest my a good idea . I have spend 2000 Rs already on clutch plates