I just installed a JD Jetting kit, removed the AIS, and installed a ZipTy fuel screw. The bike starts much easier, runs much better when cold and the choke can be pushed in much sooner after the first start. I went with all manufacturer recommendations as follows: ZipTy fuel screw: 1-1/2 turns out JD Jetting: Red needle, clip in middle (4th position from top), 165 main jet, small O-Ring on accelerator pump arm. AIS removed and plugged all connections. Home made exhaust block off piece. Rubber caps on intake and airbox connections. I live in the Pacific Northwest near Seattle Washington so I ride in mild climates from sea level to around 1500 feet. Happy trails!