hi there. ive replaced the crank seals sealed my reedvalve and all that and i still have a TIN TIN TIN. comeing down from the rev . what could this be. could this be the mikuni carburator not jetted properly the bike runs great and its hard to get it to load up. great for any riding. i just want to kno what my problem could be. any input would be appreaciated very much. thanks guys cheers!!!!!