R6timmyp

I have got a 1999 R6 with 23000ish miles on the clock. I recently noticed a noise coming from the top end of the engine?? and was wondering if anyone knows whether this is likely to be the Cam chain tensioner or un balanced carbs?? I have checked the oil...all ok. The bike has been run until very recently restricted to 33BHP, so this may also be a factor?? Any advice would be breatfully appreiciated.#