Blowing oil through case halves

[Daffoml]

My 6700 started leaking oil, badly. The engine had been a bit dirty since I got it, but now it was literally dripping down on the front suspension, and splashing everywhere, not to mention smoking like mad.  Once I cleaned it (days and 2 cans of foaming engine clean)I realized someone (one of the unlnown previous owners) had smeared a great deal of black permatex over the split in the case on the left side of the engine, between where the oil filter stay and the middle of the head, and I think when they worked on it, they cut the faring in half, and used the permatex to glue it back together.

Anyways, I've tooled with engines a fair amount in my days, and I've never seen a gasket like that leak after so many years, I've seen cork gaskets do it, not paper.  While I was asking a friend about it, he was thinking maybe the breather was clogged, and internal case pressures were getting to high.

Anyone think that is possible, should I tear the breather apart first, and see if it's the culprit?  How do I even test it?  with a car, I have a PCV valve, is there a similar thing here?  I looked through the service manual, and it only mentions it in passing. no maintenance or replacement info.

I think what my current plan is is to pull off the flywheel to the point i can pull the breather off, and clean it, maybe replace it if I can figure out a replacement.  Then if it still leaks pull the motor apart and permatex the case halves together again.

I know that's a rambling note, but I've been working on it off and on for weeks, and am getting tired.


Thanks

Mike

[YamaDog]

On our yt3800 we had the same problem. My brother put to much oil in the crank case and blew the gasket  It blew out on top so it would only leak when running.  Had to remove boot that connects motor shield to muffler shield then removed motor shield.  cleaned the motor with engine cleaner and found the leak. Clean that area really good and scratched up with sand paper and used high temp two part epoxy and covered well.   Had not leaked yet.

[Daffoml]

I ended up pulling the motor, pulling it apart, and making a new gasket with ultra black RTV.

These engines are rather impressive, it has variable valve timing, never seen that on a mower engine...

[tom rut]

I have a yt3600 with the same problem. Fixed it by removing boot and cleaning all dirt and oil, covered leaking seam with a thick coat of red high temp. rtv. Removed crankcase breather hose from carb. and pluged carb hose inlet. Installed a 2" by 2" fome rubber on end of hose. works no leaking oil. I also found a burned pin in wire connector at base of engine. bypassed plug, now my battery is being charged. Engine has been run on amsoil syn. since new. still runs like new. TOM RUT