User 41221

Hey Mike... I wasn't able to view your pictures, but I think you are just dealing with combustion burn residue. I haven't had the head off my 968, but on the 944S that I am working on at my house for a friend, the valves were not coated. I don't believe that the 968 valves were different. The part number for the exhaust valve on a 944S is 928 105 642 05 and the exhaust valve part number on a 968 is 928 105 642 06, so I doubt there is a lot of difference.

Regards,

RajDatta

No coating on the pistons.