my jinlun has no modifications and it does 60-65 quite easily, you could try the 2 little pipes that come off the exahust (1 on each) try blocking them with a bolt and some duck tape. it worked on my brothers jinlun. good luck. other than that theres not a lot you can do with out spending a fortune and if you lucky you may get an extra 5mph or so.
ian
January 2010