Hi if some of you already have the same problem please help me . I was riding my Bike last week when the bike sudently started to whistles.. But it is a loud whistles when i ride and when i give gaz on idel. So i've decided to take a look inside. Started bu taking off the oil who was nice and coolent.. Thats where i realised something that was not there before. In the radiator when i drained the coolent there was some white in it, like wet paper rip all in little peices.. I've took up the Clutch Case, took off the clutch, examined all gears and bering and all seemed to be fine.. I've took up the Top engine to take a look on the piston. It was fine and i had 135lbs of compression. But the powervalve and exaust was really dirty so i've decided to clean it and polish. Thats where i am, Should i check the transmission? It is starting to be colder outside and the probleme started when i switch to cheap Castrol oil... May it be the probleme???? Do you think it would be because of the temperature and i should change my jets? Sorry, it may not be clear enough, But if you have any questions to clear it up, please ask. I c'ant really see what it is... I can't hear the sound on idel, But when i give gaz thats where I hear it. Please help me and thanks for your replies.