It will not accelerate although idles fine and doesn't stall out. Air and fuel filters are clean, exhaust port clean and spark screen has been removed. Spark plug has been replaced. I removed the fuel vent while running but no change in performance. I noticed the fuel bulb is full now but don't remember seeing this bulb full while running on my other equipment The carb is the non-adjustable type other for than idle. This problem occurred all at once. It was running fine upon last use and then after sitting for one week, the problem started immediately upon start up. Any ideas would be appreciated.