I think 140 mph is an unreasonable expectation without spending thousands upon thousands, and even then I doubt that it's possible. This is not a machine made for speed. It does adequate speed, but you'd probably be able to afford to another bike stock capable of higher speeds for cheaper than making this machine faster. The real question is why would you even care about those kinds of speeds? Once I crossed 100 mph my vision started to blur. Clearly if a deer ran out into the street there was nowhere I could go. It's just insane. It's neat to have done it, but it's just too risky.
Long story short my wife wasn't wearing a seatbelt this weekend and I hit the brakes hard for a stupid reason. I was only doing about 9 mph. She hit the dashboard hard. Stupid her for not putting on a seatbelt, and stupid me for letting my testosterone get the better of me. I was doing about 9 fucking mph. Protip: we don't get seatbelts on motorcycles. And I always gear up fully, but seeing how fast and hard she hit the dashboard is terrifying. That's basically what we face every day we go out on a ride. On the plus side, we won't get stopped by a dash. On the minus side, gravity is going to slam us against pavement or ground, and then if we're lucky we're going to slide for too many seconds until we stop. If we're unlucky we're going to slam into a several ton piece of steel, possibly moving in the opposite direction which will multiply its mass in ways we don't want to think too hard about.
If you're anxious to die there are less painful ways.
If you're trying to make a competitive race bike there is a thread for that where somebody has tried. I don't want to think about how much time and money has been spend. It seems like a fool's errand. But have at it if that's what you really want.
If you're just somebody's son with too much testosterone then take a few swings at a concrete wall, drink some beer, and get back on track.
