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Just curious, wondering what the piston top on a decent running two stroke is supposed to look like. Looking down in my blower and the piston is light brown and dry. I get a small chunk of light colored carbon in the plug gap now and then too. Seems like that piston should be some oily? Should I add some more oil in the mix? I use Stihl oil. Little motor is five or six years old and get used quite bit blowing and sucking/bagging leaves.

No the piston should not be oily. Coffee colored residue is good but black isn't bad. Just depends how much black buildup. If using Stihl Ultra mix at 50:1 any heavier and if carbons up exhaust screens. You are probably good.

Think about this. I have one spark plug that is light brown after running for 25 hrs. I have another plug that is black after running for 25 hrs. Which engine would you say is running properly?

The light brown

Same with cylinder appearance. Always taught my students that the spark plug will tell you a lot about what is happening ing the cylinder.

Rivets said:

Same with cylinder appearance. Always taught my students that the spark plug will tell you a lot about what is happening ing the cylinder.

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Absolutely

Thanks for the info. I guess I was living in the past when two strokes were real oil burners.