alright man. if you throw a shim out you definitely will hear it. But don't start tearing down your engine until you know exactly where the noise is coming from. But the only way to check is take the tank, and airbox, and head cover.( those rubber gskets can be reused but i recommend for the best seal to use a new one, and use the (TORQUE PATTERN CORRECTLY!)). Then take off the head and the side inspection covers and put the engine at top dead center on each individual cylinder and look at the clearances on all the valves. (while checking obviously look at each shim and see if its there.) If you suspect a bad shim put which ever cylinder it says to put on to remove the camshafts. (either 1st or 4th)Once the cam tensioner, cams and chain have been removed, measure each individual shim and make sure it is in spec. of what application you are using whether it is race, or stock. Once you do that you will be able to tell of any wear on the top end. If you have any questions fill free to message me man. hope all goes well!