Small Engines (Lawn Mowers, etc.): oil blowing out air intake, gasoline smell, piston rings

Question
QUESTION: I have a Honda self-propelled walk behind model # HRB216HXA, engine # GHAEA-1134995 MY7*. It is smoking a LOT from the exhaust and is soaking the air filter with oil. The oil seems to be coming out of the breather tube that goes from the air intake to the side of the engine. The mower has been setting up for a number of years. Long enough for the gas in the carb to completely calcify. I installed a new carb and the engine starts but acts as described above. Does it need new piston rings or is there another problem. I installed the carb without making any adjustments. I have only the owners manual for this mower, which doesn't help me with this problem.
Any ideas or suggestions are greatly appreciated.
Thank you for your kind assistance.
Tim

ANSWER: Did you change the oil?  Is the oil level correct?  Does the oil smell like gasoline?  Was the mower tilted on it's side?

Eric

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

QUESTION: Eric,
Thank you for your prompt response. I put fresh oil into the engine before trying to start it. The oil is at the proper level. I cannot detect any gasoline smell in the oil. The only time the mower was tipped on its side was to drain the old oil. Otherwise it sat upright for a few days before I tried to start it. It does start reasonably well but smokes badly from the exhaust and pumps oil out of the breather tube.
Thanks again,
Tim

Answer
Can you access the breather to clean it.  Most breathers can be removed and cleaned with parts cleaner or carburetor cleaner.  Is the dipstick tube o-ring sealing?  I'm wondering if the engine is not maintaining a vacuum and oil is getting past the piston rings.

Eric