My 2001 Yamaha V-Star Classic 650 has been sitting in my garage for 2 years. I'd break it out and ride it a few miles every month or so, but the last two months I've had problems. The bike has trouble starting, but when it does it idles so low it dies. I've adjusted the idle screw but no luck. In order to keep it going I have to stay on the gas. Any ideas?