Blowers

I have a poulan pro bvm200vs blower. I repair small engines and I have checked every thing and I was wondering is there a fly wheel key for this blower? I have looked at diagrams and cannot find one, but it appears that there needs to be one by looking at the notch on the fly wheel and shaft. I also wanted to ask another question. I have no spark coming from the unit. I have replaced the spark plug and gone through the entire unit. Is it that there is a missing fly wheel key causing this or is the magneto assembly bad?