How do you read spark plug colors?

How do you read spark plug colors?

1. The first step is removing the spark plug you want to look at.
2. A normal spark plug will have brown or grayish-tan deposits on the side electrode.
3. Black, dry soot on the electrodes and insulator tip indicates a carbon-fouled plug.
4. Black, oily deposits on the electrodes and insulator tip points to an oil-fouled plug.

What color is a good spark on a spark plug?

In general, a light tan/gray color tells you that the spark plug is operating at optimum temperature and that the engine is in good condition.

What color is a weak spark plug?

A black, feathery carbon deposit on your spark plugs can be an indication of a weak spark or an overly rich fuel mixture. Causes may include a stuck choke, misadjusted or heavy carburetor float, a leaky injector or carburetor needle valve, low coil output or high resistance in your spark plug wires.

What are the signs of a bad spark plug?

What are the signs your Spark Plugs are failing?

• Engine has a rough idle. If your Spark Plugs are failing your engine will sound rough and jittery when running at idle.
• Trouble starting. Car won’t start and you’re late for work… Flat battery?
• Engine misfiring.
• Engine surging.
• High fuel consumption.
• Lack of acceleration.

What does orange spark plug mean?

A bright blue spark is best. A yellow/orange spark signifies weak ignition.

Should spark be blue or yellow?

The strength of the spark is revealed in the color. A red or yellow spark is weak and probably will not spark in the cylinder. A blue or white spark is strong and has enough voltage to fight across the spark plug gap even under pressure within the cylinder.

What Colour should a good spark be?

On an automobile ignition system the spark should be bright blue. That’s because the compression ratio is higher than that on an air cooled small engine. An automobile engine operates under a transient condition where the RMP’s change so fuel demand changes.

What does a GREY spark plug mean?

That looks dark grey and can mean you are too rich BUT, that’s a tough one to call because lighter greys and this could be heading there are caused by too much heat from too much timing or too much compression. Too much heat can burn the color right off the plug even if you are jetted about right.

How can you tell if a spark plug is rich or lean?

Rich running conditions: If your engine is running too rich, the spark plug will be black and sooty. Lean running conditions: If your engine is running too lean, the spark plug will be white. If the spark plug is black and oily, they are oil fouled.

What does a fouled spark plug look like?

Oil fouling of a spark plug typically results in a shiny, black appearance. If enough oil is in the combustion chamber, the deposits can build up on the tip, porcelain or shell. If you can’t determine if it is carbon or oil fouling, smell the plug; it will smell like engine oil.

What does a bad spark plug sound like?

When your spark plugs are performing as they should, your engine sounds smooth and steady. A fouled spark plug causes your engine to sound rough while idling. You might also feel the vehicle vibrating.