I have an engine here that has slight leakage of the '80cc' slant cylinder head near the front, toward the exhaust post side. There are some posts here that say this type of head is prone to warpage, so probably that is what is happening to this one. The head has a raised lip or ring around it, so if I were to lap the head, I would just be lapping this inner ring ,and not the larger square surface of the head where the head gasket rests upon. I thought that the seal is made by the entire gasket flange, but it looks like the raised ring of the head indents and pushes down upon just a tiny bit of the head gasket, only around the inner circumference of it, and pushes it down into the cylinder bore, instead of pushing down upon a flat surface. Wouldn't it be better to remove this raised ring and then lap the head so that the square surface that makes most of the contact with the head gasket is the part that is being lapped and flattened? More gasket surface area that is flat makes a better seal, no?