Engine Oil in Carb - GCV160

[wy307]

New mower with Honda GCV160LA0S3B engine. Ran fine for 3 uses then wouldn't start. Pulled the carb, lot of oil inside, thought I had tilted it the wrong way when I went to hose it off. Cleaned the carb and both inner and outer jets, completely, in an ultrasonic cleaner, started on 5 pulls afterward. Next time 10 pulls, 3rd time 50+ pulls, 4th time won't start. Pulled the carb, same issue with oil inside, total mess. Definitely not caused by tilting it the wrong way. Mower is Husqvarna HU700H, engine Honda GCV160LA0S3B with auto choke, carb is 16100-Z8B-901 / BB76A A.

What are the possible causes of oil in the carb?

 

[reynoldston]

I would think high crankcase pressure would cause this. bad gaskets, internal engine problems, plugged crankcase vents, anything that would build up pressure in the crankcase.