NGK B6HS Spark Plug – Stock No. 4510
The NGK B6HS is a reliable, short-reach spark plug for many classic and small-capacity engines, including popular two-stroke motorcycles, scooters, and small air-cooled engines. It delivers a consistent spark for clean combustion, easier starting, and smooth idle.
Its medium heat range helps prevent fouling in stop-start use while protecting against overheating in sustained runs. The short 12.7 mm reach suits cylinder heads designed for half-inch threads. This plug is non-resistor, giving a strong signal but potentially more electrical noise than resistor types.
- Strong, reliable ignition for everyday use and light performance tuning
- Short-reach design for classic heads and small engines
- Durable nickel alloy with copper core for stable heat control
Check fitment: Suits many classic two-stroke motorcycles and small engines that use a 14 mm, short-reach, non-resistor plug. Use the vehicle lookup to confirm, or see the Vehicle Fitment tab for full details.
| Specification | Detail |
|---|---|
| Part Number | B6HS |
| NGK Stock Number | 4510 |
| GTIN | 087295145104 |
| Category | 686 – Spark Plug |
| Thread Diameter | 14 mm |
| Thread Pitch | 1.25 |
| Seat Type | Flat seat with gasket |
| Reach (thread length) | 12.7 mm (1/2 inch) |
| Hex Size | 20.8 mm (13/16 inch) |
| Heat Range | 6 (medium) |
| Resistor | No (non-resistor) |
| Center Electrode | Copper core, nickel alloy |
| Ground Electrode | Standard J-type |
| Projection | Non-projected tip |
| Terminal Type | Solid terminal |
| Factory Gap | 0.7 mm (0.028 inch) |
| Service Note | Adjust gap to the engine maker’s spec |
Helpful notes
– If you experience radio interference or use sensitive electronics, consider an NGK resistor equivalent (e.g. BR6HS) if suitable for your engine.
– Always match reach, thread, and heat range to your engine to avoid damage.
The price displayed is for a single plug, please add the desired amount to your basket.


