You have left fuel in the mower for extended periods, and it has gone stale and produced gum and varnish. You can add 2 ounces of auto fuel injector cleaner to the gas tank, working it through with the primer button and trying to start it. This might work, but will take a few days. The carburetor will most likely need to be cleaned. Discard any old fuel you have. It can be added to your auto tank without any harm. Get new fuel and always use STA-BIL fuel stabilizer every time you fill the can. Then the fuel is automatically protected if the mower has to sit for a while.

i drained all the gas and bought new gas and some fuel injector cleaner. I put a couple of ounces in with a full tank of new gas. I got it started after about 20 attempts of priming 6 times and starting, dies after 2 or 3 seconds. Eventually it stays running. I have it running in driveway now with vice grip on handle so I dont have to stand there with it.

Engine code is YBSXS.1901VC 274466

Model will be 5-6 digits Something like 12H802
Type will be 6 digits "" 2328-B1
Code will be 8 digits "" YYMMDDff

okay i got it this time:

12H802-3119-B1 01020956

Refer to this link. It's a simple fix-

http://forums2.gardenweb.com/forums/load/lmower/msg0510320517891.html?5

'i drained all the gas and bought new gas and some fuel injector cleaner. I put a couple of ounces in with a full tank of new gas. I got it started after about 20 attempts of priming 6 times and starting, dies after 2 or 3 seconds. Eventually it stays running. I have it running in driveway now with vice grip on handle so I dont have to stand there with it.'

Good. It worked this time. Now don't forget the stabilizer or you'll be doing it again.

Well...I tried to start it this morning without cleaning the main jet. No luck. So I unscrewed the main jet and looked at it and it looked very clean and unplugged. But, I used a bread tie and pushed it through and down in and I also took carb off and looked at it. It looked very clean. I used the bread tie and pushed it down the long horizontal very small opening on the carb (lower left corner if looking at carb mounted on engine). I was kind of skeptical, I put it all back together and primed it three times and it started and stayed running (smoothly) on the first pull. WOW! Thanks. Any idea why it looked very clean but still made a difference? There was a little resistance on cleaning that long horizontal minute opening. Might that have been it?

Varnish buildup may not be that visible, but still reduces the diameter of the passage.
If you BARELY don't have enough fuel to run, the result is the same as if the passage is totally clogged.
I would recommend a strong dose of carb cleaner in the tank for the next couple mowings to help clean out the passages that you can't see.

okay, thanks for the help!!!