After using up 2 rolls of shop towls and 2 cans of engine degreaser, I finally got all the gummy goop out that I possibly could. I hosed that stuff down and let it sit overnight before I even touched it. I had a drip pan on the floor to catch some of it.

While I was at it, I ran the wire wheel in the cordless drill on the top of the engine. I got most of the baked-on crud off the top of the valves, and also got most of the old gasket off.

Now you can see the valve springs and the piston cylinders inside there.

That goop was hiding everywhere! I must have sprayed that stuff with engine degreaser a dozen times. I filled up the trash can with shop towls, and it took a week to get my hands clean. Whew!