Small Engines (Lawn Mowers, etc.): John Deere Rx75 smokes wont stay running, john deere rx75, crankcase pressure

Question
Eric,
I picked up an RX75 last year. It has the 9hp Kawasaki FC290V. Ran great. Near the end of season I accidentally overfilled the crankcase, when I saw all the smoke realized what I did, drained it, filled it correctly, and a little smoking more cleaned up and all was good. This year bringing it out for the season realized I left the petcock open. Oops! But she fired right up without a hitch. Was blowing some white smoke and would shut down after about a minute. Would restart again and again and shut. down after about a minute. Before digging into it fired it up a day later, white smoke but stayed running. Since my grass is getting longer by the day figured I'd cut with it and see. Smoke got less and less and went away, but after about 10 mins it shut down. Restarting it I was right back to where I was. Smokes and dies after a minute. There's a bit of oil in the exhaust. Not pouring out but it's there. The oil smells a little of gas. So I started with the air filter. At the bottom of the air filter box there was a pool of oil at the chamber that leads to the carb. Took carb off. Needle and seat seemed ok. So disassembled and soaked the carb in cleaner. Found a manual at the library and it mentioned a crankcase pressure relief reed valve located on the top of the cylinder on my model and on a couple others in the rocker box. Can't find this valve anywhere to check it. I still want to do a compression test. What am I looking at here? Thanks for any input!

Answer
If fuel leaked past the inlet needle and got into the oil then you need to change the oil.  Refill with fresh oil.

Since you know it has been burning oil I would replace the spark plug, preferably with an NGK brand spark plug.

With fresh oil and a new spark plug see if it will run.

As for the crackcase breather, see page 77 via the link below.

http://www3.kawpowr.com/enginesecure/ServiceManuals/FC290V.pdf

Eric