I have had a athena 47mm tuning sylinder and a ninja lowboy exsost on mine... it whent like crasy.. but after a short time.. my gear bearings became crushed... i took of my sylinder and put on my orginal sylinder and still had my eksost... after 3 days the bearings whent again... note: I did not "push" my bike all it got... so my perposol is too get better bearings to the gears...
ive alsow gott som fju styling tips if your interested.. e-mail me for more info...