What spark plug is everyone using 08 crf250r?

[Tim Allen Elvington]

What spark plug is everyone using in their 2008 and up CRF250R? I just purchased one that has a CR7EIX in it. Anyone using this plug with any luck?? It isnt what is recommended, according to service manual.

[Hudson Charlton]

Don't run it. For all we know some goofball but a spare plug in. Stick to what your service manual said. Good for you, for checking the manual.

[mlatour]

Parts Pit Stop microfiche lists either an NGK 8 or 9 heat range plugs for that application,

the CR7 is one heat range hotter than recommended. (NGK codes = the higher the number, the cooler the heat range)

 

Inspect it closely with a magnifying glass under a light for signs of pre-ignition,

like 'fusion' between the center electrode and insulator and/or tiny shiny metallic specks embedded in the surfaces.

 

Using that #7 plug under heavy engine load, running bad fuel (low octane) or with lean carb settings, could be very problematic.

Edited November 13, 2017 by mlatour