chili88gt

Got my 01 f4i stunt bike. Runs decent, fuel pressure regulator is bad i think. Got one on the way. But its been making a really nasty sound.... Coming from the top end. On the throttle side. You don't really hear it at idle, but once you get the rpms up its almost like a rattle-type noise. I know the f4i have cam chain problems. And im familiar with cam chains on cars, but not on bikes. Could the cam chain need an adjustable tensioner? Or maybe something else? Im hella scared of blowing up the top end, or bottem end for that matter. Any help is appreciated. Thanks.