John Deere acting up, then wouldnt start.. Help?

Sorry for the vague title and the non gear head description, Im not much for working on small engines other than a carb rebuild here and there on a weedeater or chain saw .. So heres the chain of events... I started mowing this morning and made 5 or 6 passes through my side yard, the grass was kind of wet but not very thick so it wasnt clogging anything up, and all of a sudden the sound of the motor and output changed and I shut it off. Tried to start it and it wouldnt. It seemed like it would turn over just not fire.

Heres what ive checked/done: Full of oil and gas (The slingblade does not apply here), spark plug was very black, so i changed that. Cleaned around all the pulleys and belts.

Again I apologize if the description is to wide or vague and thanks in advance for any help. It's an 18.5 B&S motor thats only got 43 hours on it. Heres the shitty part, warranty was 24 months; I have owned it for 24.5 months.

 

Check the air filter.

With the low hours I would have said the plug should fix it. Last year I had this issue with my Craftsman mower. Changed the plug and it fouled out again the next week. Stupid me forgot to look at the air filter..SOB was clogged like you read about. I fired the mower without the filter and it ran like a champ..replaced the filter and no more issues.