Small Engines (Lawn Mowers, etc.): Briggs and Stratton 445577 engine in Husqvarna Mower, briggs and stratton, lowes

Question
I purchased the mower listed in May 2008 from Lowes.  It has 8.8 hours on it.  I mowed and had to leave.  I came home and put new gas in the mower and it wouldn't start. Have a NEW Corp Extended Warranty.  The Service Provider took the mower and now says the engine is clogged with Black Residue, asking how old my gas was.  I purchased it that day.  He contacted Briggs and Stratton and they say they aren't responsible.  The provider told me to contact them.  Should I be concerned that this NEW MOWER is requiring $290 worth of repair.  It only has 8.8 hours and has had NEW gas (From Sheetz) each time it was filled at each of the only five times I used it this summer!!  It is kept in an out building and I take good care of my mower.  The air filter was clean and it had plenty of oil in it.  WHY WOULD THIS HAPPEN and how do I get the manufacturer to cover the problem.  I can't afford to have it fixed, especially since I just paid $3000 for it in May.  Thanks for your opinion!!

Answer
Hello Barbara:

What does the "Service Provider" Say the Black Residue is? What is the Black Residue Blocking? Is it Blocking the Carburetor, the Valves, the Rings, ect? What Repair is the "Service Provider" Going to Do for the $290.00? I have Never Had this Problem Occur and Really Need to Know what the Black Residue is. Once I Know What the Black Residue is, I can Assist you Better. Thanks.

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John