Small Engines (Lawn Mowers, etc.): Murray Select mower dead?, briggs stratton, mulcher

Question
Hi, Michael-
I have a Murray Select walk-behind mower, model #224110X8A, 4.5hp (Briggs & Stratton), 22" cut, convertible mulcher, that I bought new in the Fall of 2003.  It has never been taken in for repair.  

For the first year, it worked great.  Then, it started having trouble--it would suddenly quit in the middle of mowing and could not be restarted.  Sometimes, if left alone for a few days, it would work again.  Also, it emitted some smoke while it was on.  I changed the air filter, which seemed to help it (I thought that had fixed it, actually, because it began to work consistently again).

Then, after several months of running fine, again it began to quit working in the middle of a mow.  Since the end of this past Summer (2005--it was 2 years old), I have been unable to get it started again.  I have put new oil in it, it has plenty of gas, and I prime it before I start mowing.  

It has been suggested to me that perhaps the spark plug needs replacing--is this possible on such a new mower? And if so, is that worthwhile (and easy) to do? As far as I can tell, the plug is currently connected.

One thing that seemed to be affecting it before it stopped working altogether was that sometimes the primer button didn't seem to work; it didn't seem to be pushing any gas (you can hear when it is, and I could hear nothing; also, it wouldn't start).  When I tipped the mower backward a little and primed it, it seemed to get the gas where it needed to be, and the mower would start.  Could this tic be anything that would affect its running?

Also, does the age of gas affect how the mower runs?

Is it possible my relatively new mower has just died?

My yard is not very big, but I would like it to be shorter! Please help.

Thank you-
Tara  

Answer
Hi Tara,

A spark plug should be replaced yearly or at least every 2 years.  Unscrew it and replace with a new one.  
Old fuel deteriorates in a few months and will gum up a carb.  During storage it is best to add stabilizer to the fuel, to prevent this.  
If after a new plug, there is no change, I would suspect a gummed carb.   Try to start it while squirting fuel or starting fluid into the carb intake.  If it starts and you can keep it running by adding fuel, then the carb most likely has dirt, debris or gummed fuel inside.   
You will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.   Probe each and every hole with a
small wire.   Adding a carb rebuild kit wouldn't hurt either.  This may be more than you are able to tackle but if you have it done at a shop, you will know what to expect.  

Let me know how you make out.
Michael