Thank you very much! Luckily, however, it was much simplier. I had bent the blade so badly that it was nearly scalping the yard with the one side (maybe I would have realized this sooner if it wasn't so dark). I bought/installed a new blade this am and it is back to normal. The fact that the stop/safety handle didn't stop the motor as quickly as normal is still puzzling. The WHAM, I think, was simply a rock that was picked up out of my driveway because of the bent blade being so close to the ground. I'm still not sure if the grinding sound is normal - almost sounds like it needs greased - there are no fittings on the shaft are there? Cool site. Glad to know it is available. I'll be back with a riding mower question. Thanks again!