# CR9EIX NGK Iridium Spark Plug | Genuine NGK Spark Plug

## 🔧 Product Description

**NGK Iridium Spark Plug – Part Number: CR9EIX**

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: 3521
-   Thread: 10 mm
-   Reach: 19 mm (3/4 in)
-   Hex: 16 mm (5/8 in)
-   Seat: Gasket

## 🚘 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.

-   Yamaha 212S (1100 cc, 2010-2008) – Inboard Engine
-   Yamaha 212X (1100 cc, 2010-2008) – Inboard Engine
-   Yamaha 232 LIMITED (1100 cc, 2009-2008) – Inboard Engine
-   Yamaha AR210 (1100 cc, 2010-2006) – Inboard Engine
-   Yamaha AR210 (1049 cc, 2015) – Inboard Engine
-   Yamaha AR230 (1000 cc, 2006-2004) – Inboard Engine
-   Yamaha AR230 HIGH OUTPUT (1100 cc, 2009-2005) – Inboard Engine
-   Yamaha SR210 (1100 cc, 2007-2006) – Inboard Engine
-   Yamaha SR230 (1000 cc, 2005-2003) – Inboard Engine
-   Yamaha SR230 HIGH OUTPUT (1100 cc, 2007) – Inboard Engine
-   Yamaha SX210 (1100 cc, 2010-2007) – Inboard Engine
-   Yamaha SX210 (1049 cc, 2015) – Inboard Engine
-   Yamaha SX230 (1000 cc, 2006-2003) – Inboard Engine
-   Yamaha SX230 HIGH OUTPUT (1100 cc, 2009-2005) – Inboard Engine
-   Kawasaki (Jet-Ski) STX (JT1500D) (1500, 2010-2009) – Personal Watercraft
-   Kawasaki (Jet-Ski) STX-15F (JT1500-A) (1500, 2014-2004) – Personal Watercraft
-   Kawasaki (Jet-Ski) STX-15F (JT1500-C) (1500, 2004) – Personal Watercraft
-   Kawasaki (Jet-Ski) STX-15F (T1500AAF) (1500, 2010) – Personal Watercraft
-   Kawasaki (Jet-Ski) STX-15F (JT1500AFF) (1500, 2016-2015) – Personal Watercraft
-   Kawasaki (Jet-Ski) ULTRA LX (JT1500) (1500, 2014-2007) – Personal Watercraft
-   Kawasaki (Jet-Ski) ULTRA LX (JT1500KFF) (1500, 2016-2015) – Personal Watercraft
-   Kawasaki (Jet-Ski) STX-12F (JT1200-B) (1200, 2007-2003) – Personal Watercraft
-   Yamaha FX160 (1100, 2004) – Personal Watercraft
-   Yamaha FX HO (FX1100) (1100, 2006-2004) – Personal Watercraft
-   Yamaha VX CRUISER, DELUXE, SPORT, R,S (VX1100) (1100, 2015-2005) – Personal Watercraft

That is the 25 most common of 247 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: 3521, 4132, 4191, 5366, 5633, IU27, IU27A, U27ES-N-ZU and 3 more
-   Harley Davidson/Screamin' Eagle: 31600012, 31600085, RG6HCC
-   Champion: RG6HCC
-   Harley-Davidson: 31600085

## 📦 Condition

-   Brand new genuine product
-   Supplied in original packaging

## Details

- **Price:** 41.0 AUD
- **Vendor:** NGK
- **Type:** Ignition & Controls

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 41.00 AUD | In stock |

## Images

- CR9EIX NGK iridium spark plug

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/cr9eix-ngk-iridium-spark-plug-genuine-ngk-spark-plug)
> Updated: 2026-09-03