Walk Behind Lawn Mowers

I purchased a 7021P in january 2012. I have had to get the carburetor cleaned and some small adjustments done in May of this year. Now all of a sudden the engine started smoking and using oil. Then it just stopped while mowing and would not crank again. It seems like the carb has trash in it again. I have taken it back to a Husqvarna "P" shop. I asked about the engine smoking and warranty. They wee very vague and offered to check out the mower and maybe give me money against a new mower. Do I have a right to repair or replacement under warranty ? I have changed the oil, replaced blades and air filters and all the usual maintenance stuff. Of course there is normal wear and tear after mowing a one acre yard and leaf catching during the winter. So I am very unsure about my rights. All I know is that I still need a mower...my grass is growing! Shouldn't this Honda engine last longer that 18 months? Thank you