How do you read spark plugs?

[BikeSAG]

Ok.....here is what I know to be correct when reading spark plugs:

Gray (or grey) to light brown is good.
White represents a condition that is too lean.
Black represets a condition that is too rich.

Attached are the plugs just changed from my 2007 Heritage with 35000+ miles. I have never run a fueler.

I like that they look the same for each cylinder.

Agree?? I'm interested in you opinion.

 

[SledDog]

They look ok to me...

 

[aron50]

Sounds like everything I ave read but I have no first hand experience.

 

[Hoople]

Reading plugs with a closed loop fuel injected system is almost meaningless, especially with ethanol fuels . It tells you nothing about the air/fuel ratio at WOT & steady cruise speeds which is so important. Fuel ratio's are not blends like they are with a carb. They are sharp cut off points.

 

[glider]

Ok.....here is what I know to be correct when reading spark plugs:

Gray (or grey) to light brown is good.
White represents a condition that is too lean.
Black represets a condition that is too rich.

Attached are the plugs just changed from my 2007 Heritage with 35000+ miles. I have never run a fueler.

I like that they look the same for each cylinder.

Agree?? I'm interested in you opinion.

Spark plug reading isn't what it use to be since the lead was removed from fuels. Most of the plugs pulled in modern day engines will be white and any color that is found is due to fuel additives and not a mixture reading. Quite often a change in fuel brands will yield a different color on the plug.

 

[NEWHD74FAN]

The plugs look fine, but as others have said, you can't "fine tune" fuel like the "good ol' days" on street machines using modern fuels.

That is why there is a whole industry built around dynos and computerized telemetry type dynamic fuel metering/exhaust monitoring the GP bikes in racing circles these days.

 

[Jack Klarich]

Reading plugs with a closed loop fuel injected system is almost meaningless, especially with ethanol fuels . It tells you nothing about the air/fuel ratio at WOT & steady cruise speeds which is so important. Fuel ratio's are not blends like they are with a carb. They are sharp cut off points.

For every day riders I agree it is almost impossible now to read plugs unless you have sophisticated tools and know how, this may shed more light on how racers read plugs Reading Spark Plugs Correctly

 

[speedyron]

get a dobeck TFI and see how much better your bike runs. Then you will be able to adjust fuel.