Small Engines (Lawn Mowers, etc.): Lawn boy 8461 - gas leak thru valve, exhaust ports, cutting blade

Question
Tom,
Lawn Boy mower 2 cycle model 8461 (built in 1987) has started leaking gas when not in use.  It is wet on the underside of the mower body.  I looked up a parts diagram online, then removed the cutting blade and the muffler cover (good bit of carbon then scraped off).  It appears gas is coming from the valve exhaust ports.  Engine starts on the 3rd or 4th pull, idles and runs at fster speed OK.  Why is gas leaking?  Stuck float, maybe? I see no gas/oil stain around the bearing seal on the crankshaft.  Is the easiet fix to install a gas line cut-off valve and start cutting the gas off when not in use?
I'd really appreciate your advice and experience,
Craig

Answer
I would check my fuel line from the carb to the tank for any dry rot. After that assuming there are no other leaks I would suggest a carb rebuild as it seems the float needle is not stopping the fuel from over filling the bowl into the carb........Tom