NGK CR9EIA-9 Iridium Spark Plug – Stock No. 6289
The NGK CR9EIA-9 is a high-quality iridium spark plug built for reliable ignition under hard use. It delivers a strong, stable spark for cleaner combustion, smoother running and better cold starts. Ideal for performance-focused motorcycles that run hot and rev high.
It uses a fine-wire iridium centre electrode that needs less voltage to spark. This helps reduce misfires at high RPM and under load. It is also more durable than standard copper plugs, so change intervals are typically longer. Expect better throttle response and consistency, not a big power gain.
Technical specifications
| Part number | CR9EIA-9 |
| NGK stock number | 6289 |
| GTIN | 087295162897 |
| Category | 686 – Spark Plug |
| Thread diameter | 10 mm |
| Thread reach | 19 mm |
| Hex size | 16 mm |
| Seat type | Flat seat – gasket |
| Heat range | 9 (NGK scale – colder plug) |
| Resistor | Yes |
| Centre electrode | Fine-wire iridium |
| Ground electrode | Nickel alloy |
| Spark gap | 0.9 mm (factory set) |
- Stronger, more consistent spark at high RPM.
- Improved starting and smoother idle.
- Better knock resistance under load due to stable ignition.
- Longer service life than standard copper plugs.
Fitment guidance
Widely used in many high-revving Japanese 600-1000 cc sport bikes that specify NGK CR9E-type plugs (Yamaha, Suzuki, Kawasaki and others). Always confirm with our vehicle lookup or check the Vehicle Fitment tab before ordering.
Important: The gap is set to 0.9 mm from NGK. Check your vehicle’s spec. If adjustment is required, do so carefully to avoid damaging the fine iridium tip. Install only into a cool engine and torque to the manufacturer’s setting.
The price displayed is for a single plug, please add the desired amount to your basket.


