Small Engines (Lawn Mowers, etc.): Sears Lawn Mower, (Rubber Bubble leaks Fas), gas leaks, hp model

Question
QUESTION: I have a sears push mower that is in excellent condition, (6.5 HP,) Model 917.388522.  It started first pull for years, (3 pumps on the bubble).  Recently it has been hard to crank, (7 pumps).  After it runs for awhile it stalls.  I can pump again and it will run a few moments.  SO- I pulled the tank and cleaned it, replaced the gas hose, replaced filter and cleaned area. Now that all is back together, gas leaks out from the rubber bulb area. Took apart and reset all parts and it still leaks.  Could it be the bulb? Tiny air bubble appear out of the small whole on the bubble. Any help would be appreciated.

Thanks,

Tom

ANSWER:    Gas is leaking out there, because the carb is flooding.  You need to remove the bolt on the bottom of the carb and drop the bowl down.
Inside there is a plastic float on a hinge, that is what lets in the fuel, and is supposed to shut it off when there is enough.  Either the float is stuck, or the needle valve is bad, or has a bit of dirt blocking it open, or the float may be cracked and not floating.
   When the other things are resolved, if the gasket between the air cleaner and carb is not in great shape, the primer will not prime.
  Let me know what you find.

  Fish

---------- FOLLOW-UP ----------

QUESTION: Thanks for the note.  I small rubber insert was a nor set properly. I reset it and the leak is stopped.  All looks well, but!

I am now back to where I started.  The mower cranks fine and will run for a about 10 seconds.  After several try the mower will run continuously, but the idle is low. After priming and cranking again,RPM's sound good, but will eventually will idle back down.  

1) Replaced air filter
2) Replaced spark plug
3) Checked carburetor,(float appears to be fine)
* carburetor is very clean
4) Checked needle valve and appears to be fine. I ran low pressure air in attempt to rid any debris
5) Replace gas line from tank to carb,
6) Drained all gas and replaced with gas purchased 4/12/2009

So I am stumped at this point. It still appears to be a gas flow issue

Answer
   The rubber seat may be "sticking", but before replacing try this:

Remove the bolt/jet that holds the bowl on and look closely at it.
you will see small holes in the side and center, clean these out
thoroughly.  Also look for a tiny one at the base of the threads
and clean that one with a wire, reinstall and see how it runs.