I have a Bolens 21in cut B/S mower (Model # 11A-414W765) that "was" running fine until it started stalling like it was out of gas. It was able to start a few more times after that, but eventually hit the normal RPM's then just died off from there. Now, she wont start at all. The string is fine, and shes not locked up, its turning the blade but just has no resistance to it when I pull it. It's about 5 years old but only has 2 cutting seasons on it. What is the next step to see if shes dead?