NGK Spark Plug DPR8EA-9 4929

Product Information

Copper is generally seen as being the best metal to use in terms of conductivity but iridium plugs are seen as premium as they last longer than standard plugs and can be built with smaller tolerances. Iridium spark plugs also have lower voltage requirements, meaning they perform better when starting and idling and some manufacturers also claim they offer a better throttle response. The metal in a spark plug has a single purpose: to channel the electrical energy through the spark plug. Iridium is far harder than copper and this allows the spark plug manufacturers to create a plug with a sharper ‘tip’ which better focuses the spark around the centre electrode without compromising its service life.

The NGK Standard Spark Plug is constructed from durable material that is corrosion and abrasion resistant. The spark plug insulators are made of 99 percent pure alumina silicate, allowing for longer insulator noses for reduced fouling. This spark plug features a triple gasket sealing process that eliminates fuel leakage. It also includes a solid copper core that provides superior heat dissipation and conductivity. This spark plug has resistor that is produced with a glass and carbon mixture, which is fired to ensure superior performance and durability. It has corrugated ribs that prevent flashover and cold rolled threads to inhibit damage to the cylinder head. Note the image may not be exactly as item received and any slight difference will not be inferior or effect performance

Iridium Spark Plug vs Standard

If you’ve not changed your plugs before, give yourself a couple of hours to complete the task. Here are the essentials you need for smooth re-plugging: This nifty little tool only costs a few quid and will help you set the correct gap for your spark plug. However, modern plugs are almost all motorcycle-specific fit and so they come ‘pre-gapped’ and you won’t need to touch them. If you’re running a classic bike, you’ll probably need to set your gap and if your bike’s not running right, a gap tool can help you rule out a potential incorrect gap issue. Most parts are pattern or aftermarket although some will be genuine but are not always stated as being so.

If the plug is brown or light grey your can assume your engine is in good condition and the spark plug is functioning well. Even when a plug is in good condition small deposits will accumulate. This is normal. Rich If the engine is running dangerously lean the whole plug tip will be grey or white. If the temperature is over 850-degrees, pre-ignition may occur. Engine power will be reduced and you risk piston damage.

A typical copper spark plug will last around 20,000 miles and most get changed at a major service (usually around 16,000 miles) but an iridium spark plug will be good for around 50,000 miles and you do see people running them to 100,000 miles with no issues. Install each spark plug by hand until you have wound the thread a couple of turns. This reduces the chances of you cross-threading the plug.