I just did mine today.... then I read your post...
I also used a 1 3/8" hole saw because I happened to have 2 snap in button plugs that size - in case things turned to crap...
I didn't have a lot of time afterwards but I managed a short test ride. The bike seems a little stronger, but I don't think I got 9 more hp out of this mod. A longer test ride is in order.... here's hopin'!!!
