Before you go and disassemble the whole engine it would be a good idea to first look at the spark plug. This can give you important clues about what is going on in there. The one spark plug condition that was not mentioned on the chart is the meltdown. The sparkplug will have melted metal around the gap, and is not typical but can be caused by a lack of good oil in your engine(CHANGE YOUR OIL). As long as I am talking about spark plugs I should also mention that if your spark plug gets striped you will need to buy something called a heli coli, which will patch the damage.