The NGK 6668 V-Power Nickel spark plug is a replacement plug for 2008-2025 Yamaha models. It has M14-1.25 threads, a 1.043 in. reach, a 5/8 in. (16 mm) hex and a heat range of 6. A V-groove cut in the nickel alloy center electrode improves ignitability over a flat-tip nickel plug.

NGK 6668 V-Power Nickel Spark Plug Features:

• Fits 2008-2025 Yamaha models; see Fitment tab for all applications
• M14-1.25 metric thread with 1.043 in. reach
• 5/8 in. (16 mm) hex
• Flat seat with crush washer installed
• Heat range 6
• 0.036 in. factory pre-gap
• Nickel center electrode tip with nickel ground electrode tip
• Resistor type (5000 ohm) for ignition noise suppression
• Non-removable nut terminal
• 1.990 in. insulator height
• V-groove cut in the nickel alloy center electrode improves ignitability over a flat-tip nickel plug
• Copper core center electrode draws heat away from the firing end
• Alumina silicate ceramic insulator for high dielectric strength
• Trivalent metal plating resists corrosion and thread seizing
• Intended for engines that originally used nickel alloy plugs, not as a replacement for factory precious metal plugs
• Sold individually