The 89 CR125 blew another head gasket last week so I thought the head might have warped a little from the first overheating, I am fixing it old school.
I could see some discoloring here and this would be the hottest part of the head which is right above the exhaust port.
I colored the head so when "lapping" the head I could see high or low spots.
A piece of glass and some 150 emery for the initial cutting. I know this is not the same as machining but this is vintage racing?
You can see the low spots