Stuck or fuel-logged float, causing fuel to leak down and flood the engine, as I warned you could happen in the previous thread. The 'band-aid' fix is to put a fuel valve in the fuel line between the tank and carb, and turn it off when you're finished mowing. Typically you will find an oil spot where its stored from the residual oil remaining after the gas evaporates. The real fix may be as simple as shaking the float loose by bouncing the deck once or twice. You could then use a solvent oil like MMO in the fuel, at about 2 oz/gal, to help clean up any gummy residues in the fuel system. I had the same thing happen on my Duraforce engine before I started using it. I'd go into the shed and get hit by a strong gas smell, finding a wet spot on the wood floor under the mower, so I struck a match to see what it was - just kidding! :) Seriously, its a real hazard in an enclosed space.
You may not be able to stop it with these methods, which leaves you needing to overhaul the carburetor.
Bear in mind that excessive oil smoke on a 2-cycle can only mean either too much oil in the mix or too much mix entering the combustion chamber and muffler.

saxman1:

Thanks for replying.

My garage has a dirt floor, I looked where the mower sits and there was a very small darkish area, but it didn't seem like it would have been enough for the loss. It's also possible that the spot is an old one as I do remember spilling oil in that area a number of years ago. As far as the smell of gas I couldn't say as I don't have a sense of smell.

Could the stuck float be the cause of it's sporadic failure to start? If the float is stuck allowing the fuel to leak wouldn't that negate the need to prime the engine?