Champion N21 long reach spark plugs for the well known Petter A1, A2, W1 and W2 petrol engines. For series 2 engines produced 1951 onwards.
A direct equivalent of the Lodge BL14 or NGK B4ES plugs used in these engines.
| Manufacturer | Champion |
| Part Number | N21 |
| Diameter | 14mm |
| Reach | 19mm (3/4") |
| Hex Size | 20.8mm (13/16") |
| Seal Type | Gasket Seat |
| Resistor | No |
| Terminal Type | M4 Thread |
| Electrode Material | Standard Nickel |
| Projection Type | Non Projected |
| Tip Configuration | Single Electrode |