Hello all my first post..  Just wanted to thank everyone for all the post and helpful tips.  I just bought my Thumper a few weeks ago. just hit the 600 mile mark. I broke it in the first 200 mile bone stock.  Then the fun began. Thanks to all the great info i now have a great sounding, hard runner, and just all around fun bike to ride.  I have put a jardine muffler, K&N air filter, and rejetted perfectly.  no backfire while riding no puff, poot, capow on shut down. Next projects are sissy bar install ,wind shield and gonna do something with taillight and licence plate bracket.. will keep ya posted .. thanks everyone..