Not clear to me. Is the head off the bike?
If so, remove the valves. You can make a valve spring compressor with a C clamp and a piece of pipe or PVC. Remove the valves and look at the wear pattern on the faces. Then use some light lapping compound, and lap the valves. Look again. Take a black Sharpie and ink up the contact areas of the valve and seat faces. Using a small amount of light compound, lap the valves again.
At that point, it makes sense to post some pics of the were patterns on the valve and seat faces.
One of my rules in life is that if it takes longer to talk about something than to do it, you should probably just do it.
Practice and exercise called the "Two Handed Push", whereby you push away the keyboard and actually some work