# BR9EIX NGK Iridium Spark Plug | Genuine NGK Spark Plug

## 🔧 Product Description

**NGK Iridium Spark Plug – Part Number: BR9EIX**

Iridium NGK spark plugs offer a longer service life than a standard nickel-tipped spark plug: while nickel-alloy plugs offer a service life of roughly 20,000-40,000km, NGK Iridium IX spark plugs offer a service life of up to 60,000km, so fewer replacements are needed over time despite the higher initial cost.

Precious-metal spark plugs like the NGK Iridium IX also offer higher ignitability, achieved with an exposed fine-tip centre electrode that promotes superior flame growth compared with a standard spark plug. Iridium has a much higher melting point (2410°C) than nickel (1453°C), allowing the centre electrode diameter to be reduced from 2.5mm to 0.6mm – a smaller electrode mass that reduces the impedance to flame progress, helping acceleration, fuel consumption and idle quality.

## ⚙️ Key Features

-   Fine iridium-tipped centre electrode for a slow wear rate and stable idle
-   Longer service life than standard nickel plugs
-   Trivalent metal plating provides superior anti-corrosion and anti-seizing properties
-   Corrugated ribs reduce the risk of flashover
-   Pure alumina silicate ceramic insulator, providing superior strength and better heat transfer
-   Copper core aids in heat removal
-   Triple seals prevent leakage

## 📏 Specifications

-   NGK stock number: 3981
-   Thread: 14 mm
-   Reach: 19 mm (3/4 in)
-   Hex: 20.8 mm (13/16 in)
-   Seat: Gasket
-   Type: 14mm Spark Plugs cont'd

## 🚘 Application

Listed in NGK's application charts for marine, motorcycle, ATV and snowmobile equipment. The gap is not the same on all of them – the chart lists between 0.5 mm and 1.0 mm depending on the engine, so check the line for yours.

-   Aprilia AS 125 R (125) – Motorcycle
-   Aprilia ETX 125 (125, 1998-1984) – Motorcycle
-   Aprilia ST 125 (125, 1998-1982) – Motorcycle
-   Aprilia STX 125 (125, 1998-1982) – Motorcycle
-   Aprilia TUAREG (125, 1998-1986) – Motorcycle
-   Aprilia TUAREG WIND 125 (I) (125) – Motorcycle
-   Aprilia AF1 50 (50, 1998-1986) – Motorcycle
-   Aprilia ET 50 AE (50, 1998-1987) – Motorcycle
-   Aprilia ET 50 FIRE (50, 1998-1987) – Motorcycle
-   Aprilia GL 50 (50, 1998-1993) – Motorcycle
-   Aprilia LX 50 (50, 1998-1993) – Motorcycle
-   Aprilia MX 50 (50, 2004-2002) – Motorcycle
-   Aprilia RED ROSE 50 (50, 1998-1987) – Motorcycle
-   Aprilia RS 50 (50, 2005-2002) – Motorcycle
-   Aprilia RS 50 REPLICA (50, 2004-2000) – Motorcycle
-   Aprilia RS 50 TUONO (50, 2004-2003) – Motorcycle
-   Aprilia RX 50 (50, 2004-2001) – Motorcycle
-   Aprilia RX 50 (50, 1998-1990) – Motorcycle
-   Aprilia RX 50 RACING (50, 2004-2003) – Motorcycle
-   Aprilia TUAREG 50 (50, 1998-1987) – Motorcycle
-   Aprilia TUONO 50 (50, 2005-2004) – Motorcycle
-   Beta REV 80 (80, 2008) – Motorcycle
-   Beta REV 80 (80, 2004-2003) – Motorcycle
-   Beta REV50 (50, 2004-2002) – Motorcycle
-   Beta RR 50 MOTARD (50, 2012-2008) – Motorcycle

That is the 25 most common of 438 applications NGK's charts list for this plug – ask us to check yours.

## 🔄 Supersession & Cross Reference

NGK's cross-reference tables list this plug against these part numbers.

-   DENSO: 3981, 4048, 4166, 5317, 6901, IW27, W27EPT, W27ES-GU and 2 more
-   Bosch: W3CP, W3CS, WR3CP, WR3CS
-   Motorcraft: AG603, AG603C, AG701X, AGR701X
-   Champion: N86G, QN2G, RN2G
-   Autolite: XS4062, XS4062DP
-   Brisk: L12W
-   Magneti Marelli: CWP10L

## 📦 Condition

-   Brand new genuine product
-   Supplied in original packaging

## Details

- **Price:** 30.0 AUD
- **Vendor:** NGK
- **Type:** Ignition & Controls

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 30.00 AUD | In stock |

## Images

- BR9EIX NGK iridium spark plug
- BR9EIX NGK iridium spark plug firing end

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/br9eix-ngk-iridium-spark-plug-genuine-ngk-spark-plug)
> Updated: 2026-09-03