i have a smaller tec engine on a yard vac, if full it pushes oil from breather, if low on oil it doesnt, i hardly mess with it but doesn't look like anything is wrong, no idea why it does it, annoying for sure. Engine doesn't have many hours on it either, i got it from brother who claimed it always did it.
So.. just saying, sorry i cant help ya.

#1 Crankcase pressure from a non-functioning positive vent system. May be a cracked or disconnected PCV hose. This has been posted here before, but I don't remember the details of how that system works.
#2 Could be a bad upper seal - the engine has positive lube to the upper bearing - not really pressure, but it keeps it wet. Easy to change after you get the flywheel off.
#3 Over-filled crankcase?

Warranty.

Check the oil level. If overfillled this could be an issue. Also, does the oil leakage occur when you are mowing crossways on a steep hill?

Are you tipping the mower to clean under the deck? Check oil level as in too much oil? ???

Significantly overfilling, tipping etc can explain why a Tecumseh top mounted breather will pump oil thru the hose. But if it is a consistent external leak, and the OP noted he is adding oil - it likely needs a breather kit, maybe a seal. Warranty / shop repair if he can't pull the flywheel.

Hi all, thanks for the feedback. To clarify, I mow on all level ground, I don't tip the mower excessively (I lift up the front enough to take the blade off to sharpen); it just leaks! It doesn't leak immediately on start-up; it takes a little while to start leaking. Then it leaks as long as the engine is running. I can't get the flywheel off because I don't have a tool. And by the way, lots of luck to get warranty work done here on Maui. They don't want to do anything unless you pay them, and if you didn't buy the machine from them, they won't talk to you. Besides, I wouldn't trust them working on the mower anyway. How hard is it to change out the breather, providing I can get the flywheel off? Any help will be appreciated.

The breather is simple. Maybe for cheap they would pull the flywheel and send you on your way. You take a real chance damaging this flywheel w/o using a puller. You could hope it comes off easily and try this at your own risk. Remove the hardware on top the flywheel and reinstall the nut flush. Tie the safety bail up to release the brake. Pry up carefully under the beefier side of the flywheel, close to the key, on a solid spot on the block and rap the top of the crank. I still suggest either buying a puller, or maybe a dealership-at that least that way you could get it covered under warranty...

I had this same problem after nearly three years of ownership. The mower warranty was still a few days prior to expiration (Toro extended the warranty to three years for mowers purchased between March 29, 2007 and July 5, 2007), so I took it to an authorized dealer for repair. On the first repair attempt, the dealer replaced the breather gasket. On the second repair attempt, they replaced the breather itself. On the third attempt, they finally did some honest troubleshooting and found that the governor shaft bushing was leaking which they replaced.

"And by the way, lots of luck to get warranty work done here on Maui. They don't want to do anything unless you pay them, and if you didn't buy the machine from them, they won't talk to you."

Where are you Yungman? Another good example of the exemplary service provided by the small, independent shop. The only thing they do well is complain because internet sales and big box stores have put them out of business.

Put some Liquid Wrench on the flywheel nut and let it soak in for a couple hours before folliwng tomplum's advice. I did that recently on a 25 year-old Tecumseh engine that had seen a lot outdoor storage, and the flywheel came off on the first hit (and I didn't even smack it or pry that hard). And check your local hardware stores for a Tecumseh flywheel removal device -- IIRC Ace is supposed to carry them, and they're only about $5 here on the mainland. Check Amazon, too.

http://outdoorpowerinfo.com/repairs/flywheel_removal.asp

Here is a link that might be useful: http://outdoorpowerinfo.com/repairs/flywheel_removal.asp