What color should spark be on spark plug?

If the firing end of a spark plug is brown or light gray, the condition can be judged to be good and the spark plug is functioning optimally.

What does a good spark on a spark plug look like?

A normal spark plug will have brown or grayish-tan deposits on the side electrode. Everything is just fine with your spark plug; you can reinstall the spark plug.

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.

How do I know if my spark plug is lean or rich?

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.

Why are my spark plugs yellow?

Caution: Running the engine with a lean fuel mixture will cause the engine to overheat and burn the electrode of the spark plugs. Pay close attention to the High-speed Needle adjustment. Running the engine with the proper fuel mixture will make the spark plugs appear yellow at the ignition point.

How To Diagnose and Read the Color of Your Spark Plug

What do spark plug colors mean?

By examining the insulator firing nose color, an experienced engine tuner can determine a great deal about the engine's overall operating condition. 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 does Blue spark mean?

Just before a plug touches an outlet, when the two are very close to each other, an electrical current from the circuit will reach across the tiny gap and create a spark. This small, blue spark is normal.

Should spark plug spark be blue or orange?

Orange sparks are like slow sparks that miss fire and creates other problems, so blue is more effective and that's how ignitions are designed to properly be efficient. Orange sparks could mean ignition problem in the coil, a bad ground or too much resistance.

What does a white spark plug mean?

If your spark plug is white in color or appears blistered, that means something is making the plug run too hot. Check for problems in your engine's cooling, a lean fuel mixture or incorrect ignition timing.

What do black spark plugs mean?

Black spark plugs are a sign of a weak spark or too much fuel in the air-fuel mixture.

How do I know if my spark is strong enough?

The proper method to check for spark is with a spark tester. It resembles a spark plug but has a sunken center electrode that simulates a load on the coil. Holding the plug wire and seeing if a spark jumps to ground is inconclusive. The spark is arcing in atmospheric pressure.

What does a weak spark look like?

A good spark will be blue-white and will be plainly visible in daylight. If a good spark is present, the problem is probably not in the ignition system. Check the fuel system and/or stark timing. Weak sparks are orange or red and may be hard to see in daylight.

What are the symptoms of a bad spark plug?

What causes weak spark?

A weak spark, or no-spark, problem may originate within one or more common ignition system components: Worn or damaged spark plug wire insulation. At high temperature, this problem can produce bucking or misfires. Dirty or worn spark plug.

How do you fix carbon fouling?

What does a bad ignition coil look like?

Once the engine is cranked, you should look for blue sparks along the spark plug gap. If you can see blue sparks, this proves your ignition coil is working correctly. If you don't see blue sparks or you see orange sparks, this is a sign that there's a problem with your ignition coil.