Small Engines (Lawn Mowers, etc.): Craftsman lawn tractor fuel in air intake, craftsman lawn tractor, gas vapors

Question
My sister in law's craftsman tractor was leaking fuel.  I thought just a hose or something simple, but when trying to start it, it cranked a couple of turns then stopped dead like it hit something solid.  I manually turned the engine backward and tried again with the same results.  I took off the air cleaner, and the was gasoline everywhere.  A few soaked rags later I then tried again, and as long as I didn't apply the choke, it kept spinning, but as soon as I choked it to try and start, it filled up with fuel again, and locked up.  I've never seen this before, and also with the air cleaner off, when I manually turned it backward, gas came out in the middle of the air cleaner.  Any ideas here?

Answer
 Hello Roger:

 **STOP** Check the Crankcase of Gas Contanimation. If the Oil Smells of Gas, then Change the Oil. Leave the Crankcase Open to Air for at Least 24 Hours for all the Gas Vapors to Leave the Crankcase and then Refill with Oil. The Carburator Float Needle is Not Stopping the Gas Flow to the Carburator and this Allows the Cylinder to Fill Up with Gas and Seep by the Rings Into the Crankcase. Install A Cutoff Valve in the Gas Line and Turn Off the Gas Flow when the Mower is Not in Use. The Carburator May need Cleaning and Rebuilding. Even if you Rebuild the Carburator, the Cutoff Valve is Still Required. Check the Gas Tank Cap and Ensure it is Venting the Tank Properly. Just about All the Mowers I have Worked on in Recent Years are having this Problem and a New Needle and Seat Helps for a Little While, but it Comes Back in a Few Months. Thats the Reason for the Cutoff Valve. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John