Just spay some WD-40 and it comes out. A bit rust on the lower cylinder wall (see the picture) and the piston (red circle). Does it look acceptable and could be cleaned up with a quick honing? Should I order the new ring or just use the old ring. New ring is too much expensive!

• This reply was modified 3 years, 4 months ago by Evinrude 25.

There are 3 things seized up: The mag plate got seized up with the block neck, the gear case got seized up and the lower piston got seized up at the intake port. The water contacts the piston at the intake port (red circle on the picture). I have removed all the bolts out without heat. I have no ideal of the grey stuff on the head gasket. Only ATF contacted the head gasket when I removed it so. Not sure what you refer to the gray stuff.

I am glad it turns out good inside. By the look of out side, I expected all bearings, crankshaft got rusted since it was in the water and people just hang it in the garage for a couple years.
So It will be my winter project to get this one back running. I had the learning experience from my 1973 20 Hp so this one should go well.