B&S Sump Gasket Failing

I have a 2005 Husqvarna with a Briggs & Stratton 24 HP (446677-0463E1) which started leaking oil late last year and I let it sit until spring of course! After my first cut in April I decided to no longer neglect it and tear it down. I found the crankcase gasket was the culprit and it appeared to be sucked in below one of the cylinders (oil filter side). I cleaned everything up and replaced sump gasket, breather gasket (reed valve) and shaft seal. I fired it up today and started cutting grass stopping often to check for leaks and less than hour into cutting it started leaking. Upon further inspection it appears the sump gasket blew out this time near middle of the two cylinders. I really don't know if I goofed the install or I might have more serious issues going on with this engine. I did use permatex ultra black gasket sealer and cleaned everything meticulously with razor blade and brake cleaner, torqued as manual specifies. This engine has 8 years of Midwest home owner usage (about an acre) and well maintained. I just don't see a gasket actually blowing out a one inch chunk due to install. Any thoughts or ideas? Before I throw another gasket and hours into this engine?

I hate to say this to a new member, but I think you blew it when you installed the gasket with Permatx sealant. Sump gaskets are designed to be installed dry, if you got too much sealant in one spot, it will not allow the sump to be pulled flat. Just my opinion.

Wow! A One-Inch Chunk GONE? That's some serious pressure! I've heard of strong blow-by but usually it goes into the carburetor or the valve cover rather than blow a sump gasket. One thought I had was maybe the sump is slightly warped and may need some minor leveling up. You'd have to lay it on a flat surface and check with a feeler gauge. I never use any sealers on sump gaskets. That would be unusual to have a warped sump but it could be similar to a warped head on an automobile that keeps blowing head gaskets. Wish I could help more.

Thanks for the thoughts! The sump and block are both flat checked them with a 12" scale before assembly. I guess I can try the dry gasket next run. That would be great news if permatex was the issue but I'm not holding out much hope.

Be careful using permatex or any kind of sealer. My 27 HP commercial turf b&s started leaking around 350 hours. It was under warranty so I let the authorized repair shop fix it. When 970 hours rolled around, I was having overheating and low oil pressure problems. Oil light would come on after about 20 min of mowing. Couldn't figure out why. Cooling fins were clean and I stay on top of maintenance well. I was thinking bad oil sensor, then the rods started knocking at 1000 hours. I use this mower to make a living so I ordered another engine as soon as I got home. I had to know why it failed so I took it apart and found strings of red permatex that had broke loose from the sump sealing clogging the pick up screen for the oil pump. The authorized repair shop had gone out of business, and B&S said it would be the repair shops responsibility for any compensation. So I had to eat the cost of a new one.