yes, simplest mod you can do. $16.95 atdenniskirk.com. look for a Honda XR650L or a ninja 250 sprocket, those are the ones you need. immediate notice in performance as it lowers the gearing. do it now! no, you will not need a spacer if you order like the above info provides.

edit: just checked, they have one left. hurry as these sell like hotcakes. depending where you live denniskirk.com will get it to you in one day. i live in Iowa and they ship from Minnesucka.