Can anyone tell me what's wrong with it? It's a Craftsman ridng mower with a 14.5hp Briggs & Stratton engine its 7 years old good up keep & never had a problem with it. One day I strted it and smoke & oil started to pour out the muffler.

Never seen it, I would suspect cracked block.
Do you have Water in Oil, Oil in Water.
What Vehicle and Engine do you have?
Intake/Exhaust manifold Gasket, Head Gasket.
Plugs may tell you something, Also Compression Test.
Although it doesn't sound good. Doesn't mean it's Shot
Need Motor Info, Keep fingers crossed.

Your rings are probably blown. Are we talking car, tractor or what?

It looks to me that in his question he is talking about a Craftsman riding lawnmower.

Thanks hvac, the full explanation didn't show when I firstvread the thread. Just said oil coming from miffler. Hey, tried to apy you a compliment a few minutes ago regarding one of your answers but this darn Dell or my dial up is acting up. Kept getting an error message. Nice job.

Not a problem, I thought maybe you missed something. Thanks for the compliment!

Fuel has leaked past the carburator and into crankcase causing level to rise. Probably a piece of debris in the carburetor. Change oil start and let run 5 minutes and do it again.

It will smoke like hell for a while. It is easy to assume the worst but trust me it happens all the time and people misdiagnose it all the time.

Don

I think question had changed, I also missed riding lawnmower.
Tought was car, you were talking about.

The only time I ever had oil come out of an engine, I had a generator, that one of my "ex" employees moved for me. They were a hateful bad employee, so they stored the generator upside down, it sat upside down for about 3 months till we noticed ( it was in a wrap frame so could sit that way)

When we turned it right side up, oil was coming out badly.
A complete clean out by one of my new employee had it going good,
But will asssume a lawn tractor would not have been stored upside down.

Strat, you aren't imagining things, when you and I first answered there were no details. NEW's answerr is definitely a possibility but I'm staying with blown rings. Keep up the good work.

Well of course this is why I never answer in power tools, my idea of a good mower is one someone else is pushing. I was actually interested in what it could be myself, I had this picture in my mind of oil just shooting out of the muffler like a water hose,

Most small engines NEVER get the hours it would take to destroy a set of rings, it happens in the odd case but rarely.

Working in the power equipment industry you come across oil out the muffler on a regular basis and it is almost always a fuel mixing with oil problem.

Don