Clear the the gas from the oil system

I got my PoulanPro PP19A42 (19 hp 42”) out yesterday. I hitched up the trailer and did some hauling, and then started in my the first mowing of the areas that I mow. All was fine for a while, and then it began to run rough, and died. It restarted, but with a blast of slightly-blue-tinged white smoke. It ran briefly, got real rough, and died (with more smoke). My first thought was that I had holed the piston, even though I’ve never touched the timing.

I tried to turn it over by hand; no joy. I assumed hydraulic lock, and that didn’t square with a hole in the piston. I pulled the spark plug, and good news! It was filled with gasoline. I turned it over by hand and gasoline poured out of the spark plug port. OK, it’s probably a stuck float, or float valve – or maybe a dissolved float valve seat or seal.

I tore into it today. I’ll have a carb here tomorrow, as well as a couple of plugs and a couple of air filters. It should be an easy install (if they send that ACTUAL carb, not something that’s just similar).

My question is, how to do a decent job of purging the gasoline from the crankcase? I can’t drop the pan – it doesn’t have one. Of course, I’ll change the oil and filter – maybe twice. I suppose I could take a heat gun to the crankcase, warm it up good, then dump the oil, then warm the crankcase some more, add the oil, and just crank it for a while. (I don’t want to actually run it until the oil filter is full and the oil galleys are purged.) Then I‘d run it to do the yard work that needs to be done, and then change the oil while it’s hot.

What would you do if it were yours? What are ‘best practices’? (This is putting me in mind of changing the oil in a car in the ‘50’s, getting the engine hot, adding a quart of kerosene, running it briefly, then dumping the oil.)

To save some of you some time, I’m really only interested in how to get as much of the gasoline out of the lubrication system as reasonably possible.

Thanks in advance!

Paul in tropical Wisconsin