I recently purchased a 2002 Triumph TT600. With my limited knowledge of bikes in general all I had to compare it to was my previous and first street bike. With the TT600 being a bigger engine, it sounded different. But after an oil change this difference in sound became more apparent. The only way I can describe it is the engine buzzes in the lower gears and it becomes less apparant in the higher gears. I donĀ“t know if this is normal or not. The bike appears to perform nicley before and after the oil change. Any ideas as to this buzz?