dirty piston tops

[harold j]

I have a 1962 5.5 evinrude which runs great. I was winterizing it looked in spark plug port and seen what appeared to dirty or burned piston heads is this normal for a motor this old.

 

[Walker]

Re: dirty piston tops

Carbon buildup on the pistons is just the nature of the beast. Too much is bad though as it traps heat.