Eddie 70

What causes or caused this to happen? Is this normal?

carlmb

Lean fuel mixture.

topless68

:yesnod: :yesnod: :yesnod:

Pete79L82

What you see is normal. When you look at the picture you will see that the two center exhaust valves (Smaller ones) are whiter than the two exhaust valves on the ends of the head. This is because there is no watter jacket between the two center valves causing them to be hotter and burn off any deposits that may form on them. The two outer exhaust valves are more grey colored because they are next to a water jacket and run a little cooler. The intake valves are darker yet because there is a water jacket between them. Also the incoming fuel helps to keep them cooler. Looking closer you can see that that all the intake valves are lighter near the exhaust valve where the run hotter and darker near the outside of the bore where they run cooler, allowing some deposits to build up.

KenSny

Yes, it may be running a little lean, but they are not that bad looking. If you remove the valves and clean them up you should be able to see lots of discoloration on the valve face and way up the stem if it is really too lean.

Eddie 70

Hey thanks for the great replies. I was kind of thinking it was too lean just wanted to get confirmation. I like the great explanaitions given.