Is there harm being done?

[Jack Klarich]

I agree it is interesting info. I may be wrong, but I think it would only apply to none closed loop O2 ECM systems. Just can't see ever getting colors and rings like that with A/F ratios and 10% alky gas of today using O2 feedback systems. But I still agree that it is very interesting.

Old very old tuners trick learning to read the heat rings on the threads and the spark lines on the insulators, Jack

 

[VanIsland]

I pulled the plugs - they were light grey - running lean
I checked for an intake leak (thanks TQuentin1) but not the way your link described - my buddy had a way of doing it, with a small propane torch, unlit, leaking propane near intake manifold and the bike running if there is a leak it would suck in the propane and you would hear a change in sound.

I don't have a manifold leak - I'm going to try and not worry about it too much and have my bike tuned on the 21st. Thanks to everyone who responded, I learned something from all!

 

[VanIsland]

Please do not go by the way the plugs look. you can tell little if any thing from plugs on moderen engines and fuel additives.
In the days before EPA it was a good tool to start with but not today.
If you use plugs in this way you will just end up worring over nothing, chasing ghost and wasting a lot of time and money.
yes if you pull them and they are all black and soot covered you can bet it is rich or if you pull them and ends are burnt off you can say it is lean the area in between is effected way to much by 02 sensors ECM and Fuel additives.

Thanks Smitty, that makes sense to me - using the condition of the plugs as a starting point only, not a diagnosis.

 

[Thorns]

In todays twin cams I have seen slight gray is better than "White". You'll never know until you get an A/F read out. You could be fat in one rpm, but lean above or below it. Plus the right way to read your plugs (old style) is to run the bike down the road, at a specific rpm, and shut it off, coast to the side of the road and remove them for a read. I think if you are seeing slight gray you are good to go until you see the tuner. YMMV.

Thorns

 

[Jack Klarich]

Dont dismiss reading spark plugs. If you understand how to do it it is not so scary. They will tell you what you need to know about the heat and firing line on each cylinder. This is what makes you faster on race day, and todays gas does make it harder to read them but not impossible, ask any racer they will tell you this info is correct, Jack