K Spark Plugs

[119240]

Traditional spark plugs, Premium, Super, Regular, High Perfermance, Splitfire, Platinum, Iridium.

"These are one step colder" colder then THAT MEAN WHAT ?

"These are for track use or high output motors" - Is that high reves. ?

I have used Bosch and NGK for years now. I do a cross reference for X5DC and get - Denso,Splitfire,Autolite,Champion,NGK,Sino.

If one spark is good, why do I need two to three sparks. Or even Iridium ?

:banghead

[Eric1514]

Spark plugs are rather boring and if one company wants their plugs to stand out from their competitors or if they want to brand their plugs as "new and improved", there really isn't much they can do except change what they are made of or the shape of the spark and then try to convince you it's better. YMMV but I think plain old spark plugs work best.

Colder or hotter refers to the distance the center electrode extends into the combustion chamber. If you have a "normal plug", a hotter one will extend deeper into the combustion chamber and a colder one will protrude less in to the chamber. Use the plug or the equivalant suggested in your manual.

Eric

[Kayseventyfive]

Colder or hotter refers to the distance the center electrode extends into the combustion chamber. If you have a "normal plug", a hotter one will extend deeper into the combustion chamber and a colder one will protrude less in to the chamber. Use the plug or the equivalant suggested in your manual.

Eric

I believe you are describing the difference between extended tip plugs and others. An extended tip plug may well be hotter, but hotter and colder usually refers to the ability of the center electrode and its insulator to carry away heat to the shell and the cylinder head.

[TOM1911]

I believe you are describing the difference between extended tip plugs and others. An extended tip plug may well be hotter, but hotter and colder usually refers to the ability of the center electrode and its insulator to carry away heat to the shell and the cylinder head.

That's true but the heat range is also the plug's ability to self clean the carbon deposits that would build up if the range was too cold as well as the electrode would burn up and cause preignition if it was too hot

[Kayseventyfive]

the heat range is also the plug's ability to self clean the carbon deposits that would build up if the range was too cold as well as the electrode would burn up and cause preignition if it was too hot

Yup. In addition, the projected tip design stays cleaner, too, because it is out in the open. I have had engines run cleaner when I went to a projected tip design with the same heat range from the same brand. Piston clearance can become an issue, though. On engine, in particular, became a little rough running around town, and needed a little time to clear out on the highway. With the projected tip plugs, town running was smoother, and the engine cleared out much sooner on the highway.

I should also add that exotic metal plugs sometimes foul less in slow driving. I have one engine that needs Bosch Platinum plugs to pass smog.

[tandmsimmons]

I put NKG Iridium plugs in and saw a pick up from 38 to 44 mpg. The Iridium plugs seem to help the bike run smoother and they are supposed to last longer. The fuel ecomomy justifies the change even if everything else is in my head.