Briggs & Stratton 35 Classic engine, blue smoke + oil residue out of exhaust + Petrol in oil

[doug9694]

With this carb setup it's really hard to get gas back into the crankcase oil, i'm wondering if you might have a fuel cap that the vent is plugged over pressuring the tank forcing gas out and into crankcase, just my 2 cents.

In my experience that happens with small trimmers and blowers, ect. The opposite is what I see. The engine running creates a vacuum and quits from fuel starvation.

 

[doug9694]

Could be valve guides of valve gummed up with carbon, not allowing it to seat properly

Gray oil is from water. Maybe some was in the tank or can used to fill it. Also if left in the rain or spray.