NGK Spark Plug - CR9EK - (10)

The NGK CR9EK is a standard nickel resistor spark plug built for high-revving motorcycle engines that call for a colder heat range. Its 10mm thread, projected tip and 19mm reach make it a direct replacement part for a range of road, sport and off-road machines that specify this plug from the factory.

It uses NGK's twin ground electrode design, which spreads spark erosion across two electrodes rather than one, along with a copper-cored nickel centre electrode for efficient heat transfer and dependable starting. Plugs arrive gapped to 0.7mm, so it's a straightforward service item for riders doing their own maintenance.

Always check your owner's manual or NGK's application guide to confirm this plug is specified for your model before fitting.

• Twin ground electrode design spreads spark wear across two electrodes for longer service life
• Nickel centre electrode with 98% pure copper core for improved heat dissipation
• Projected 2.5mm centre electrode tip
• Built-in 5k ohm resistor to suppress ignition interference
• Pure alumina silicate ceramic insulator for strength and heat transfer
• Corrugated insulator ribs reduce the risk of flashover
• Trivalent metal plating resists corrosion and seizing, so no anti-seize compound is needed
• Cold-rolled threads help prevent cross-threading and cylinder head damage
• Triple seals guard against combustion gas leakage
• Supplied pre-gapped at 0.7mm (0.028")
• Heat range 9 — a colder plug suited to high-output, hard-working engines

Confirm the CR9EK is the plug specified for your machine using your owner's manual or NGK's application guide before fitting — heat range and reach must match the engine.
Fit to a cool engine only; removing plugs from a hot aluminium head risks damaging the threads.
Blow or brush away dirt from around the plug well before removal so debris can't drop into the cylinder.
Plugs are supplied pre-gapped at 0.7mm. Because this is a twin ground electrode design, the electrodes are not intended to be bent or re-gapped — check the gap gently if you wish, but do not lever the ground electrodes.
No anti-seize compound is needed; the trivalent plated shell is designed to resist seizing, and added compound can cause over-tightening.
Start the plug by hand to avoid cross-threading, then torque to your vehicle manufacturer's specification with a plug socket and torque wrench.
Replace at the service interval in your owner's manual rather than waiting for a misfire; nickel plugs wear gradually and performance drops off before failure.
Keep spare plugs in their original box until fitting, and store them somewhere dry — a dropped plug can crack the ceramic insulator internally even if it looks fine.
Read a removed plug before discarding it: heavy black soot, oily deposits or a melted electrode point to a fuelling, oil or tuning issue worth investigating.
Don't clean the firing end with a wire brush or abrasive blaster on a plug you intend to reuse; it can damage the insulator and leave conductive residue.