Got an 07 650 and it started missing at top end under load almost like I hit the rev limiter. I get a big drop in power and have to back off the throttle almost like it is running lean on top end. Once you back off the trottle it seems to pick up power. This problem started after it sat in the garage for 2 months. Seems to run fine on flat ground. But you get started up a hill it misses. It will slowly pull you to the top of the hill, but it is only firing about every other time. Any ideas? Already drained the float bowl, no water, and already changed the spark plug, it looked toasty brown. What do you guys think?