White smoke and disconnected breather tube

[jbfloyd]

My lawn mower had been running for about 15 when it died abruptly. There was some white smoke and the crank case breather tube was disconnected. I'm not sure if the tube had gotten caught on a low bush branch a few minutes earlier, or if it just came off of its own accord - didn't see/notice when it happened. Anyway, mower shows no sign of starting now. Any ideas? Not 100% sure what the breather tube does, as i had to look online to see what it was, so I don't know if/how it would be related to the white smoke, which seems to indicate it started to burn oil. There was also some white vapor coming out when I went to check the oil.

It is a Yard Machines by MTD mower with a 156 CC engine.

 

[natenkiki2004]

White smoke is usually steam, from regular water. I've not understood why people see it coming out of their engines. I've never seen it personally. Perhaps gas evaporating does the same thing? I don't know about that.

What I do know is that black smoke is too rich (unburned gas) and blue smoke is oil burning. White smoke is neither of these. The breather tube allows the crankcase to equalize pressure with the outside world. With the piston going up and down, the volume in the crankcase changes and if it can't vent then the pressure is rising and falling rapidly which could blow a seal or... Usually there's a type of one-way valve on the engine side of the breather tube that maintains a vacuum in the crankcase.

As for why you can't start the engine again... go through the basics. Spark? Fuel? Compression?