Whats happenened to my flymo hovermower?

I was using my mower when it suddenly started making a different noise and I could smell burning, not too much, the mower was working to a lesser extent but the smell made me worried, so I switched it off. I turned it over and looked inside but could not see any vegetation or twine or anything tied round. I've only had it since this summer, but can't find the receipt.

MrsM
September 2009