Cub Cadet Original 1962 Breather Problem?

[sgraber]

Ok, I'm trying to diagnose a problem with my '62 Cub Cadet Original with a K181 engine. Whenever I start this thing up, I have pressure on the oil dipstick side of the engine to the point that the dipstick pops out - especially when I shut the engine off. It'll pop it out a good 3-4". If I'm driving it, it'll blow oil out which drips down the engine block. If I pull the dipstick out while the engine's running, there's positive pressure in there and I can feel a fine mist of oil coming out.

Thinking it was the breather, I pulled the air cleaner and carburetor and then pulled and disassembled the breather. It was pretty cruddy in there and it appeared as though the breather hole was plugged, so I unplugged it with a very tiny nail. After that, I cleaned the breather housing, reed, etc with a gasoline-soaked rag to get all of the baked on stuff off. The gaskets aren't in the best shape as I don't think this thing was pulled in years (I had to get a wood chisel out to get behind it to pry it off the engine block). The breather plate has the hole at the bottom as it should be and it's now clean. I did not replace the filter medium in the breather housing, but I do know that air can get in/out easily. It was pretty black with oil and residue though. After reassembly, I started the engine up and again the oil dipstick popped out and there's still positive pressure on the dipstick side of the engine. I do not feel air coming out of the breather port while the engine's running. I know the dipstick side of the engine should be under slight vacuum, but from what I see it's not.

Any idea what's going on? Should I completely replace all the gaskets and the filter medium in the breather? Anything else I should look at to fix this? The CC runs just fine otherwise.

[gitractorman]

Yea, you're getting blow by around the piston rings, so on the compression stroke you're getting pressure down in the crank case. It needs piston rings. Unfortunately, that typically means a full rebuild. Could just be a damaged or broken piston ring, but due to the age I'd bet that it will need a rebuild.

[birddog]

As gitractorman said, it's probably rings, but I had a K321 or maybe a K341 from a Honey Bee that had that problem. I found that the hole on the side between the crank case and the breather housing was plugged. If I remember right the hole was on the left by the governor.

[sgraber]

Turns out it was a combination of a plugged breather hole in the breather plate and a worn-out dipstick seal. I cleaned up all of the breather parts really well, opened the hole back up, installed new gaskets on the breather and carburetor, and installed a stack of o-rings on the dipstick to make it seat better. I ran it for 15 minutes today pretty hard and now have no problems with oil leakage.