Oil in air filter chamber

[NickCharles 41]

First time using the push mower this year. I've had it for 9 seasons. Had run lawnmower to empty fuel tank and drained oil at the end of November 2019 as I do each year before winter storage. Added new oil and fuel this morning. Started right up first pull. Ran fine for first 5 minutes or so. Then I got to the small incline section of my yard, thing started smoking out of the carburetor area, then stopped once I got back on level ground. Each time I headed up the slope (small slope mower has always handled it fine in the past) got the same smoke result, always clearing up after I got on level terrain. About another 5 minutes the motor slowly sputtered out. Unable to restart. Waited about 15 minutes no luck. Did some other yardwork for about 45 minutes, attempted another start, no dice. Started to disassemble to see if I could notice anything obvious and saw the air filter chamber full of oil. Also there was some oil that had dripped out of the chamber onto the base of the mower. Any thoughts? Thanks.

 

[bertsmobile1]

sounds very much like a blown head gasket
Pull the breather tube off and crank the engine
Hold your finger to the end of it
You are feeling for the air flowing around the tube
It should pump out but not suck in.
If that is OK, dip the oil
If it is overfull and smells like fuel then the carb needs to come off & have the float needle & seat cleaned so they shut off properly
If that is OK then it is Off with the head.