My Honda HT3813 riding lawn mower wont start?

I aquired a Honda HT3813 riding lawn mower. we replaced the rad last year, and the fan this year. the motor is in great shape apparently. I was mowing the lawn fine until it ran out of gas, so i filled it up, and tried to start it up again to finish the lawn but it was dead. i let it cool down, but its not starting, just silence. I really dont want to bring it into the shop again and spend more $$ on it.
if you have any suggestions, that would be great.
Thanks!!

Donna
June 2008