NGK Iridium spark plugs

[Jack Klarich]

Check out #2 on this list Many confuse this as rust

5 Things You Should Know About Spark Plugs

1. Anti-seize

NGK spark plugs feature what is known as trivalent plating. This silver- or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.

2. Corona stain

Corona stain is observed as a light brown or tan discoloration above the hex (located on the ceramic body of the spark plug). Corona stain is created by oil or dirt particles surrounding the spark plug. Spark plugs create a high amount of static electricity as they fire, attracting these particles to the exposed ceramic between the plug boot and the hex. Corona stain is completely normal and should not be mistaken for exhaust gas blow-by or broken seals inside the spark plug.

3. Gapping fine-wire spark plugs

In the late 1980s, when fine-wire spark plugs first appeared, installers used incorrect gap tools and procedures resulting in bent or broken-off firing electrodes. As a result, many people assumed that one cannot adjust the gap on a precious metal plug. While most NGK spark plugs are pre-gapped, there are instances where the gap requires modification. NGK recommends a wire-style or feeler gage gap tool, which can adjust the gap without prying against the center electrode. NGK also recommends adjusting the gap no more than +/- 0.008” from the preset gap.

4. Torque

Torque is critical in the plug’s ability to dissipate heat and perform properly. Always follow the manufacturer’s recommended torque specification. An under-torqued spark plug can lead to excessive vibration and improper heat dissipation, causing spark plug and/or engine damage. An over-torqued spark plug may cause thread damage or breakage, or compromise internal seals within the spark plug, leading to improper heat dissipation or exhaust gas blow-by.

5.“Copper spark plugs”

“Copper spark plugs” is a term mistakenly used for a standard material spark plug. A standard material spark plug traditionally uses a nickel-alloy outer material fused to a copper core. Almost all spark plugs use a copper core center to conduct the electricity, jump the gap, and promote heat dissipation. However, as an outer electrode material, copper would not be a good choice, as it is soft and has a low melting point (resulting in a plug that would last minutes, not miles). Nearly all NGK spark plugs, including precious metals iridium and platinum, have a copper core. When one talks in terms of nickel alloys, platinum and iridium, one is referring to its durability, or how long a spark plug will last before it needs to be replaced. However, when one talks about copper, he or she is referring to its ability to conduct electricity that is needed to fire across the gap and ignite the air-fuel mixture.

[prariepilot]

Check out #2 on this list Many confuse this as rust

5 Things You Should Know About Spark Plugs

1. Anti-seize

NGK spark plugs feature what is known as trivalent plating. This silver- or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.

2. Corona stain

Corona stain is observed as a light brown or tan discoloration above the hex (located on the ceramic body of the spark plug). Corona stain is created by oil or dirt particles surrounding the spark plug. Spark plugs create a high amount of static electricity as they fire, attracting these particles to the exposed ceramic between the plug boot and the hex. Corona stain is completely normal and should not be mistaken for exhaust gas blow-by or broken seals inside the spark plug.

3. Gapping fine-wire spark plugs

In the late 1980s, when fine-wire spark plugs first appeared, installers used incorrect gap tools and procedures resulting in bent or broken-off firing electrodes. As a result, many people assumed that one cannot adjust the gap on a precious metal plug. While most NGK spark plugs are pre-gapped, there are instances where the gap requires modification. NGK recommends a wire-style or feeler gage gap tool, which can adjust the gap without prying against the center electrode. NGK also recommends adjusting the gap no more than +/- 0.008” from the preset gap.

4. Torque

Torque is critical in the plug’s ability to dissipate heat and perform properly. Always follow the manufacturer’s recommended torque specification. An under-torqued spark plug can lead to excessive vibration and improper heat dissipation, causing spark plug and/or engine damage. An over-torqued spark plug may cause thread damage or breakage, or compromise internal seals within the spark plug, leading to improper heat dissipation or exhaust gas blow-by.

5.“Copper spark plugs”

“Copper spark plugs” is a term mistakenly used for a standard material spark plug. A standard material spark plug traditionally uses a nickel-alloy outer material fused to a copper core. Almost all spark plugs use a copper core center to conduct the electricity, jump the gap, and promote heat dissipation. However, as an outer electrode material, copper would not be a good choice, as it is soft and has a low melting point (resulting in a plug that would last minutes, not miles). Nearly all NGK spark plugs, including precious metals iridium and platinum, have a copper core. When one talks in terms of nickel alloys, platinum and iridium, one is referring to its durability, or how long a spark plug will last before it needs to be replaced. However, when one talks about copper, he or she is referring to its ability to conduct electricity that is needed to fire across the gap and ignite the air-fuel mixture.

Jack, It is definitely corrosion and not the "Corona" mentioned in #2. Even the Hex area is corroded. I ride in thunderstorms, rainshowers, and salt air six months out of the year on the east central coast of FL. I put this set in about a year and a half ago, so the elements have taken their toll.

I'm much more familiar with the workings of automotive applications. Ran and wrenched a B/Gas rail and a '47 Anglia Fuel/Altered in PDRA in the late '60's. I've only started working on my motorcycles since 2001.

[Jack Klarich]

Jack, It is definitely corrosion and not the "Corona" mentioned in #2. Even the Hex area is corroded. I ride in thunderstorms, rainshowers, and salt air six months out of the year on the east central coast of FL. I put this set in about a year and a half ago, so the elements have taken their toll.

I'm much more familiar with the workings of automotive applications. Ran and wrenched a B/Gas rail and a '47 Anglia Fuel/Altered in PDRA in the late '60's. I've only started working on my motorcycles since 2001.

Yeah, I see the rust in your pictures now

My 97 FLHT did that after 1 year here in Florida

Good on you for doing your own wrenching

I am a retired wrench, have turned wrenches all my life