Small Engines (Lawn Mowers, etc.): lawn tractor, craftsman lawn tractor, followup question

Question
This is a followup question for Craftsman lawn tractor 917.270.711.  I inspected the carburetor float and needle valve in relation to white smoke at startup and gas in the oil.  Physically, the parts looked OK. I reassembled, filled with new oil and gas, and the mower started and ran fine.  After sitting overnight, when I went to restart the mower, at first it wouldn't turn over at all. Then it struggled to start, ejecting what looked like gas and oil out of the muffler, along with white smoke. So even though the needle valve looked OK, does this indicate that gas is getting by the carburetor into the engine?  I will replace the needle valve and float.  Should I consider adding a fuel shut-off valve too? Thank you again for your help.  

Answer
You can never tell by a visual inspection is a needle will leak or not.  If you install an inline shut-off valve you do not have to replace the inlet needle...just remember to always shut off the fuel valve.

I would install a new inlet needle, inspect the float and install an inline fuel shut-off valve.  Both my mowers have fuel shut-off vavles. When I'm done mowing I just turn the valve off and let the mower run until it stops leaving the carburetor practically empty.   I never have to worry about a leaky inlet needle.  Next time I mow just turn on the fuel shut-off valve, check the oil and then start the engine.  No worries.  

Eric