We have a Yard King riding mower. Last week my husband told our grandson that he could mow over this small tree stump that was sticking up... about an inch in diameter. Needless to say, he couldn't. :) When he started to do it, the deck hit and the lawnmower died. They couldn't get it to restart, so thinking that the battery was 2 or 3 yrs. Old, my husband bought a new one. It still won't start. I read somewhere there is a safety on the mower deck? Could this possibly be the problem? We just got this one paid for and really hate to go into debt for another new one if it is a minor problem. Any suggestions anyone? Thanks for your time.