I just purchased a Weed Eater One, and out of the box I have concerns. My biggest concern is a loud rattling that comes from under the engine while it's in drive. When I push the clutch/brake in the rattling goes away. It sounds like a clanking noise. This happens whether the mower blades are engaged or not. Also, when I engage the blades, the machine shakes and the engine almost stalls. I've also noticed the engine sputters quite a bit. I'm assuming (hoping) none of this is normal? Did I get a lemon?