My 2006 510 SMR has 11,000 miles of spirited street use and the valves have never needed adjustment. When I try to pull the stock street gearing at low throttle on 5th or 6th gear on level grownd I hear the "marbles in a can" sound of detonation. It happens under 5000 rpm. I changes spark plugs and jetting trying to fix the problem. I use 93 octane primium gas and even tried octane boosters. It is not chain slap because I am familiar with the way that sounds. Do I need a new piston to fix this problem?