This rat bike was constructed from mostly free discarded parts and pieces. The terrible vibration I was experiencing from the 100T drive pulley in my 7G trans that had .100 inch runout was eliminated when I replaced it with a 4G pulley. I know this glasspack muffler from Amazon is more quiet and flows better than the one in the kit. All that is left to do is to drill out the main jet because it's running too lean as verified by the fact it runs better with the choke half on. I want to thank you all who have helped me along the way with this build. I've learned a lot from all of your combined experiences.