Originally Posted by wayne z
I was always taught that you read the plug that way for the right fuel/air ratio, not fuel/oil ratio. Brown is good, lighter is too lean, and dark is too rich
That could be it; I can't remember, just remembered the colours.
I just thought it was fuel and oil under the presumption of bad or good mixes, whereas air played more of carrying the fuel and oil into the chamber to burn.
But fuel to air makes sense too, but if that's the case, how would you check how well your mixes are?