urem37by plugs

Ron Babos · Post by **Ron Babos** » Tue Oct 17, 2006 22:35

Checked my 37by plugs the other day and they don't really show much brown on them. Practically none. The strange part is the old Champions were brown when I took them out and replaced them. The Unisons look almost like fresh out of the package with a slight lead grey tinge . I'm running 100LL and MMO. I'm not experiencing any simptoms of being too lean and there is some carbon on the piston tops which is grey colour also. If I was too lean the carbon would have vaporized showing a clean piston top.
Could I be a touch on the lean side or is it just the nature of these plugs to remain exceptionally clean?
My shutdowns are with fuel off at 1200 rpms until fuel is exhausted to burn any excess lead off the electrodes . Since I only have and use one impulse to start this helps to stop the lower plugs from fowling for the next startup. Could this be giving me the false plug colour?
Ron

Nathan K. Hammond · Post by **Nathan K. Hammond** » Tue Oct 17, 2006 23:42

It's just the nature of the plug. After 105 hours on mine, they look brand new! Wish I had changed to them a Long time ago. Remember, grey is good.

nkh

Ron Babos · Post by **Ron Babos** » Wed Oct 18, 2006 15:32

Nathan: The grey actually scared the crap out of me

figuring on a piston melt down or something. From what you say I'll consider it as normal.
Ron