I really need some help with something. The bike has been running funny for a while. It seems like it will only achieve 80 percent power, but I have to run it with the choke half on. I don't know if its a jet problem, carb broblem in general, or the fact that I'm running an open exhaust (which I plan on changing). When it's not choked theres literally no high-end. To top it off, it won't do any more than 65 mph. Which is no fun.