Understanding the NGK Spark plug codes:

The combination of letters and numbers assigned for every NGK spark plug is not only the type designation, it is a logical formula which contains the important details for the function of the spark plug.

With this spark plug formula NGK has standardised its entire assortment and made the specific characteristics of the respective spark plug clearly recognisable.

The typical NGK designation is as follows:

  • The first group of letters (either 1,2,3 or 4) before the heat rating number indicates the thread diameter, the spanner size needed for the hexagon nut and the design. (resistor, projected tip etc)
  • The first number in the sequence indicates the heat rating. (eg BKR5EIX is a 5 heat range plug. High numbers are progressively COLDER, lower numbers are progressively HOTTER)
  • The next letter identifies the thread length. (eg BKR5EIX)
  • The following letter contains data about special spark plug construction features. (eg BKR5EIX means the plug is an Iridium type)
  • And a possible final number may codify special electrode distances. (eg BKR5EIX-11 means the plug is gapped to 1.1mm out of the box)


  • This is a great link to a lot more info from NGK about their plugs LINK



Bultaco - NGK B5HS

Beta Rev3 and EVO (2 strokes): BP7RES

Gas Gas JT/JTR/JTX/Contact/Pro/Racing/Raga/Factory 95-17, Ossa 11-15, Scorpa ST/Twenty 11-17, Sherco 99-17 - BPR5ES or BKR5E

Montesa 4RT -  CR6EH-9

Montesa 314-315 94-04  -  BR6ES

Jotagas 12-17, - BPMR6A

Vertigo Combat 16-22, - BPMR6A

TRS 16-22 - BPRMR4A and BPMR6A (6 heat range is standard, 4 is a slightly hotter plug that works well with some low quality fuels)

1999 - 2017 Sherco - BPR5ES

2017 Sherco ST Factory, Scorpa Factory and all 2018 Sherco and Scorpa until present: BPR5HS

25 Products Found