I have a Craftsman push lawn mower with a 5.5 hp engine. This spring it started blowing oil out of the breather tube. What can cause this? What do I need to check?

What brand engine? Its either a faulty breather... the engine is too full of oil or there's gas in the oil.

Craftman lawn tractor, blowing oil out of breather. And smoking like hell out of exhaustand it dies.

Ruth, you should really start your own new post with this issue. Click on ASK YOUR QUESTION and start a new one. I think both of you should drain your crank and start with fresh oil up to the fill line only. Inspect the oil for separation whicj may indicate gas is mixing with the oil. This could be caused by a sticking needle valve in the carb.