new problem that just started with my pa50II. it was running really well this season and just a few days ago it started dying when i would hit about 15mph. it would run like normal up to 15mph and then it would die like there was no gas. if i put the choke in, it would rip again for a bit and then act like there was no gas. it still idles fine and runs up to like 15, but then it dies. i assumed it was a air/fuel issue so i adjusted that, but could only get it to reach 20mph and then it does the exact same thing. when you screw out the air/fuel screw, does that allow for more gas to reach the motor? does this sound like just an air/fuel, idle screw issue, or could a dirty carb cause this problem. or possibly a bad mix of oil/gas? let me know what you guys think, tomorrows the first day of riding with the guys and i'd like to go out. word.