the mower will not start with the key. the engine (B&S) turns over, but not actually start. I can pull start with only 2 tugs of the rope. I have changed the plug, new battery (charged 48 hours), new air filter (old one was past filthy), new gas (no ethanol), was it not stored with gas in it last year. any help is appreciated, but in the simplest language 
Thanks in advance for your guidance.
Thanks in advance for your guidance.