NGK 5666 CR8EH-9 Standard Spark Plug for Honda Scooters & Bikes

Vehicle Fitment

• 2003-2020 Honda NPS50 Ruckus (49 cc single)
• 2004-2009 Honda NPS50S Ruckus (49 cc single)
• 2007-2019 Honda CRF150R (149 cc off-road)
• 2007-2017 Honda CRF150R Expert (149 cc off-road)
• 2010 Honda SH150i (150 cc scooter)
• 2015 Honda PCX150 (150 cc scooter)

Features

• Standard NGK replacement spark plug (CR8EH-9) for small engines
• Solid copper core for excellent heat dissipation
• Nickel alloy electrode for reliable ignition performance
• Resistor design helps reduce electrical interference
• Trivalent metal plating resists corrosion and seizing
• Triple gasket sealing minimizes combustion gas leakage
• Cold-rolled threads help prevent cross-threading
• Universal fit across multiple Honda small-displacement motorcycles/scooters

Specifications

• Brand: NGK
• Part Number: 5666 (CR8EH-9)
• Thread Size: 10 mm
• Reach: 19 mm (¾")
• Hex Size: 16 mm (5/8")
• Heat Range: 8
• Seat Type: Flat/gasket
• Spark Gap (pre-gapped): ≈ 0.9 mm
• Resistance: Yes (≈ 5 kΩ resistor)

Included Components

• 1x NGK 5666 (CR8EH-9) Standard Spark Plug

Product Description

The NGK 5666 (service code CR8EH-9) is a high-quality replacement spark plug engineered for reliable ignition performance in a range of small-displacement Honda motorcycles and scooters. Built with a solid copper core and a nickel alloy electrode, this plug promotes efficient combustion and dependable starts across daily riding, off-road use, and light touring. Its resistor design helps reduce electrical interference with modern ignition systems, while the trivalent plating resists corrosion and seizing for easy removal at service intervals.

With cold-rolled threads to minimize cross-threading and triple gasket seals to help prevent combustion gas leakage, the NGK 5666 delivers lasting performance and peace of mind. Compatible with popular models such as the Honda NPS50 Ruckus, CRF150R, SH150i, and PCX150, this spark plug is an ideal choice for routine maintenance or tune-ups on Honda scooters and dirt bikes. Easy to install using a standard 16 mm socket, it offers long-lasting, dependable ignition life across a variety of small engines.