Hi i have a problem with my bike, its a cbr 125. When im riding like going up into 6th gear randomly somtime it will just rev crazy and go to the red. I have no idea why and have my hand no were near the clutch. It normally happens when i first set off on my journey but friday i was on it for ages it in 6th gear for a long time and it just did it. It makes me have to slow down and gets on my nerves. Any ideas? thanks.