that's because they can get into trouble if they do........and cutting the wire is about all u can do to them.....unless u want to upgrade the exhaust and intake ...even if u do all that will only move max speed to about 45-50 depending on model and will make it illegal to drive without being tagged......which means if a cop clocks u at the increased speed they can check the bike and impound it because it is now illegal to b road driven not to mention give u a big ticket ....
