I have a 2007 650 V Star Classic I had it for over a year now and for the last month or so, when I jump on the highway the bike will not go past 60mph. It feels like the bike wanting to go (almost like it want to run out of gas) and this last for about 3-5 miles, and then it will just take off. It don’t do it all the time and it slowed down on me once meaning I was doing 75 and slow on is own to about 65 for a couple of miles and then it will pick back up, why?