Just purchased a Stihl FS55 trimmer and I have a few questions. The trimmer I have used for the past 9 years is a Homelite, and it was never a really good runner so in reality I guess I don't actually know how well a trimmer should run. 1) At idle, should there be a little lope or miss to the engine? The Stihl does this. It stays running but it misses/chugs a little. 2) Also should there be an occasional miss at full throttle? It rus with excellent power, but again I can feel it miss occasionally. Just not sure how smooth a 2 cycle should be. 3) How do you get the spark plug out? I don't see a way to get a socket on it without smashing the boot or the wire. Do you have to take the shroud off? Thanks in advance for your replies.