plugs are plugs when it comes to delivering horsepower. There is not one that will deliver more or less. The questions is how often do you want to change out your plugs. there are 4 plugs for your bike from NGK. CR9EK (standard) change out every oil change-3500miles. CR9KE has 2 prongs so it has another sharp edge to choose from. $.50 -$1.00 more than the standard. Probably go every other oil change-7000miles. The irridium as a pointy sharp electrode and has a consistant contact point. Last long-no adjustments needed-about 8k-10k miles. Platinum-well, basically can hang out for the life of the bike (20k plug). The metal prong is rounded with the electrode (has the same contact distance all the way around the electrode) for a consistant spark travel and last the longest of them all. This info is in the front of the NGK buyers guide.
I'm using the cr9ke in the 9r and irridium in the 6r track bike. Changin plugs is a pain so less changes is good for me!
I used iridium plugs once and immediatly changed them. The bike was less responsive so I reinstalled the stock plugs right away. If anything, install the non-resistor type for more spark or just upgrade to a better set of coils.
From my research on the iridium plugs I've found they are built for higher temperatures to withstand deteriation over time, the material conducts electricity more efficiently which means it take less energy to fire them which is why they are just 4mm in size. The race type installed in cars are 6mm.
I think despite some plugs claiming you don't have to change them as much, you should still change them regardless of the type of electrode you're using.
I heard the bottom threaded portion of the plug actually hangs into the combustion chamber a bit on the ZX9Rs, so it will get carbon build up on it over time. If you wait a long time to change plugs then perhaps a lot of carbon can damage the aluminum threads of your head as you pull the plug out.
ok heres my .02,,, I dont think your gonna realize the 1, maybe 2 horsepower any superdeeduper sparkplug is gonna give you... what are you going for a world title... take the extra money saved and ride the damn bike !!!...or send me the difference for good advice
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