[steve89zx-6r]

My c2 model takes one of two plugs, (as the clymer manuel says) the first is for standard and high speed riding: D9EA The secon is for low speed riding: D8EA

The plugs are both the same size of course. I can not figure out why they are different. Is it no more than the temp rating? I do not understand why the 9 would not work at lower speeds, it being the same price as the 8 there is more to it than the quality of the plug.

Any thoughts?:buzzsaw:

 

[pyros46290]

it has to do with how much porcelin is around the center electrode to dissipate the heat of the plug to the rest of the engine. the hotter plug is needed to burn off excess crapp from the electrodes if the motor isnt being run hard. if the plug is too cold it wont clean itself and stuff will start to build up and eventually bridge the gap and no longer fire

 

[steve89zx-6r]

ngk plugs

mid atlantic cycles says ngk plugs get hotter as they go down in number found out today

 

[pyros46290]

exactly. get the 9ea and ride it hard