My 2004 GSXR 750 with 40,000kms on it is making a knocking sort of noise when at idle and is stalling easily when coming to a stop or at a stop once at normal operating temp. Could this be my timing chain making the noise and valves needing to be shimmed for why it's stalling? I know around the 48,000 mark is when the valves normally need adjustment so is there anyone who can listen to my bike and maybe help identify the noise and potetially also do the necessary adjustment on my valves?