Quote:
Originally Posted by rongawer
It appears to be a loaded up valve (carbon and lead combustion byproducts). As others have mentioned, brutally lean the engine on the ground - to the point that it stumbles in ground idle, and then just add a touch of mixture to keep it running. Ground idle is the main culprit in fouling plugs and valves due to the lower temperatures and cylinder combustion pressures.
A couple hours of running at full power should help clear it up, but as long as compressions are good, I wouldn't worry about it. Consider running LOP.
|
Ya just to be clear though the first picture is my valve, not the second one in the thread.
I do run LOP or at peak pretty much exclusively and lean aggressively on the ground. The deposit layer on the valve is insanely thin as my valve is really quite clean with no thick buildup anywhere. I just thought the color was interesting as I haven't seen that yellowish greenish color before.
Linear Mode
