How to Read Spark Plugs for Tuning

To read spark plugs for tuning, you do not require any professional degree in mechanics. It is also not too effortless either as there are many sections of the plugs included for reading.

How To Read Spark Plugs For Tuning

Therefore, to read them out, you need to have a basic knowledge of particular issues and their indications. To get a brief understanding, keep reading below!

So, How to read spark plugs for tuning?

Spark plug reading in motorcycle

Spark plug diagram

You can easily read and diagnose your motorcycle’s spark plugs in their running condition in an instant! Some of the basics are:

  • If you see the spark plugs black and oily at the valves or pistons, then know they got oil-fouled.
  • Black and sooty spark plugs denote rich engine running condition
  • Too lean spark plugs will show white or no color on them

Spark plug reading 101

Spark Plug Reading 101

Before the spark plugs die, they give you some valid warnings along with some physical deteriorations of themselves. To read them, you need to know what sign is a specific outlook if giving.

Such as, rusty deposits on them denote head-gasket leak or crack block.

A broken electrode/ tip can sign the worst physical friction with the piston or any concrete debris. Lastly, burnt spark plugs denote overheating or worn rings.



How do you read a lean or rich spark plug?

Too rich spark plugs will look dark brown or black. It reads, the longer your car has been used, the darker it got. It shows your vehicle’s engine is running too rich. In contrast, too lean spark plugs look the opposite of too rich. So, the spark plugs will look whitish or have no color at all.

How do you read a spark plug timing?

You can read the changing metal color on the spark plugs to know about their timing. The ignition timing is readable towards the top tip of the plug, and the end tip indicates maximum timing.

What do the numbers mean on NGK Spark Plugs?

The numbers on NGK spark plugs are the heat rating numbers. The higher the number is, the heat dissipation is lesser. A lower number indicates more heat dissipation and indicates much heat. The spark plugs use a certain amount of thermal heat to work.

What Colour should spark plugs be?

A good mixture spark plug that works perfectly fine should appear to be lightly tanned brown. Generally, it is the color that every well-performing spark plug should have. If the too black or too white color is acquired, it means the spark plugs are troubleshooting in some form.

What a good spark plug looks like?

A fresh spark plug working with optimum temperature and functioning has a slightly tan-brown color on them. These colored plugs show your vehicle’s engine is running smoothly and perfectly without any issue. The tanned brown color appears as the spark plugs start to lose their original color with time without hampering their efficiency

How do I know if my spark plug is misfiring?

When the spark plugs misfire, you will face a shaky start of the engine with rough idling. The engine will also eliminate double the exhaustion gas with misfired spark plugs and much slower, jerky acceleration. Lastly, the engine will start eliminating weird rattling noises, too, indicating things are getting worse.