Home > VansAirForceForums

-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

Old 04-21-2022, 09:34 AM
jcarne's Avatar
jcarne jcarne is offline
Join Date: Jul 2016
Location: Worland, Wyoming
Posts: 2,231

Originally Posted by rongawer View Post
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.
Jereme Carne
RV-7A Flying as of 03/2021
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 11:12 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.