Iridium spark plugs?

[Soujyu]

I'm in the process of assembling some parts to do the valve adjustment (I'm just shy of 6000 miles and the way I ride could probably hit 7500 next month). Obviously, I'm going to pick up some spark plugs, and I know I could probably use the ones recommended in the service manual. However, I know several people have successfully used iridium spark plugs, and I was keeping this option open, based on whether I can get them easily and whether it's worth it.

For those people who switched to iridium plugs, is it worth the extra price, and where did you guys get them?

[HKr1]

CR8EK FTW

^ Auto parts store can get them, and the iridiums if you choose to go with them instead.

[Snake]

I switched to iridium plugs and have not noticed any difference performance wise. I pull my spark plugs at every oil change and have noted that they stay clean but the stock plugs may stay clean as well. I don't know?

Is it worth the extra expense? - From my experience I would say no. They didn't help anything but did not hurt anything either so I guess it boils down to preference.

[WindMeUp]

Just an FYI, the NGK CR8E is the OEM plug for the Ninja with a Heat Range of 8
The Iridium equivalent is an NGK CR8EIX with the Heat Range of 8

[HorizonXP]

Originally Posted by WindMeUp

Just an FYI, the NGK CR8E is the OEM plug for the Ninja with a Heat Range of 8
The Iridium equivalent is an NGK CR8EIX with the Heat Range of 8

I appreciate this. Bought new plugs for mine a few weeks back, just got around to putting them in. Pulled out the old ones, and they were much shorter, and were marked as CR8HSA. The new ones I had were CR8E.

I used the service manual and your post to verify that I had the right ones, and that the previous owner put the wrong ones in. Here's hoping it improves things!

[Snake]

Good luck to ya. Let us know how it goes.

[bob706]

Originally Posted by HorizonXP

the previous owner put the wrong ones in. Here's hoping it improves things!

Did the bike run like crud?

[HorizonXP]

Originally Posted by bob706

Did the bike run like crud?

Not exactly. TBH, I've ran the bike for about 10,000 km on those plugs, and it hasn't seemed like an issue. But remember, I never knew how it ran before, and this is my first bike, so I just might not have known any better. I will admit that at times, my exhaust smelled like there was gas in it, like it wasn't fully burned. Also, my fuel economy has been decreasing. I'm hoping this week, I will see a difference.

[kkim]

can you post up some pics of the plugs you just took out?

[Audioguy21]

iridium plugs like the NGK CR8EIX or the DENSO IU24 have a much smaller electrodes to produce the spark. the smaller the electrode the less voltage it takes to produce the spark. so in theory this should help with throttle response. but due to the high compression and rpms of the 250s motor at high speed and rpms there are inaudible engine misfires. usually being late. i noticed my air fuel ratio start tweaking out between 8500 and 11000 rpm. ( i installed a 4wire universal 02 sensor where my headers join and mounted a digital afr guage above my cluster... didnt want to take dynojets word on what to set everything at and i wanted to be sure). i installed the new denso plugs (IU24) that i got for around 10 dollars each and the afr readings smoothed out. i would reccomend iridium plugs everytime not so much saying it gave me more ower but jsut made my bike run more efficiently. also an article i found online helps explain things a little better

http://www.automedia.com/Iridium_Spa...ht20010101ds/1

[aloh]

I put in CR8EIX plugs into my ninja when I re-did the jetting and whatnot. I dont think it made a huge difference...

[DaBlue1]

The tips of the Iridium plug are harder than other plugs, so they last a little longer and require lower voltage to ignite the air/fuel mixture. Iridium plugs also fire better with the right performance ignition coil and can increase performance better on bikes with an EFI System or High performance upgrades (pistons, carbs, cams etc..). Without a better ignition coil on the stock carbed version of the Ninja 250, you will still get about the same quality spark as from a standard tip plug. You won't even notice the difference.

[Soujyu]

Just as a update.... I ended up installing Denso IU24 plugs during my 7500 mile maintenance. I did not notice anything different performance that could have also been caused by my valve job at that time.

However, it certainly did not ruin my engine, that's for sure! Hey, maybe the iridium plugs are helping me somewhere; I just don't know about it!

[jarquin305]

when you change the spark plugs, did you change the wires??

[DaBlue1]

Originally Posted by jarquin305

when you change the spark plugs, did you change the wires??

Not sure about anyone else, but I didn't.

[Hero Danny]

I just ordered the "CR8EIX" NGK iridium plugs I was wondering if they were gapped for the ninja 250 (2012)?

The gap on them is .028

[nbleak21]

Originally Posted by Hero Danny

I just ordered the "CR8EIX" NGK iridium plugs I was wondering if they were gapped for the ninja 250 (2012)?

The gap on them is .028

According to the 2008 Maintenance Schedule: .028 - .032, so you should be all set ;-)

(I'm ordering a few today, myself.)

[Hero Danny]

Originally Posted by nbleak21

According to the 2008 Maintenance Schedule: .028 - .032, so you should be all set ;-)

(I'm ordering a few today, myself.)

Thank you

[fast1075]

To clear the air. Iridium plugs are more durable, and more resistant to erosion.

All plugs erode. That is why the gaps get wider as they age.

If changing plugs gives you a performance increase, it is because either the old plugs had a problem, or you inadvertently fixed another problem when you changed the plugs.

In some cases an incorrect plug choice will cause performance issues, that can be corrected by a correct choice. You could see measurable gains then, but not an increase, simply a restoration to "standard" performance.

Engine/tuning modifications may require different plugs. Case in point: changing cams from stock to cams with a lot of overlap cause increase in fuel/air mix richness at low rpm. If you operate the engine at low rpm, the plugs may foul. You then go up a step in heat range to help keep them clean. But if you run the engine at sustained high RPM, you may damage the plugs or engine from the plugs overheating, which causes a host of deadly engine problems.

I ran standard $2.95 each NGK plugs in my nitrous drag bikes, with no ignition issues. I am approaching 125K miles on iridium plugs in my truck with no issues. My 250 has NGK iridium simply because I know they will last virtually forever in it. (and it will happily run to the rev limiter with a sweet happy scream ride after ride).

Choose the appropriate plugs, gap and install them properly, enjoy.

[Hero Danny]

Eh, I don't mind spending the extra $$, when we are talking about a $5 increase in price, only the best for my Amy <3

I've heard mixed reviews for the iridium, I understand that they probably won't increase performance (maybe restore, as you suggested) But just knowing that these plugs will last like 5 times as long as copper, makes me feel like using them more anyway.

[nbleak21]

Originally Posted by Hero Danny

But just knowing that these plugs will last like 5 times as long as copper, makes me feel like using them more anyway.

Yep, just from a maintenance standpoint alone, it makes sense to me. Just remember to use a dab of anti-seize

[Lemonfresh]

I have read the Iridium plugs do not produce as strong of a spark as the copper core plugs. The Iridiums were introduced to fill the 100k service requirement. They will last longer than a copper core and will keep the correct gap longer. However, because Iridium has a higher resistance, they do not spark as strong as copper core.

[SV Racing Parts]

I've run both Irridium and standard NGK on a number of bikes and personally I liked the standard NGK the best, YEMV

I haven't any benefit in the Irridium to justify the extra cost to date,

Enjoy the ride, and best regards,
Blair

[InvisiBill]

Originally Posted by FOG

The ease in which the electrons are knocked off the electrode is improved by the sharpness of the edges. As each electrons leave the electrode to journey across the gap, it takes a bit of the electrode with it (like packing a sandwich for a trip). As the edges of the electrode become rounded, the force necessary to cause a spark to jump the gap is greatly increased. Couple this activity with the heat thing, and you have the reason for the exotic metal. The hotter the electrode is made to run, the less likely it is to foul. So when you look at your plugs, don’t worry too much about the color, but look very hard at the sharpness of the edges of the center electrode. When you can see a rounded shape, discard that plug.

The tiny size of the electrode is also not to conserve expensive metal, but to reduce the size of the electrode to provide a small an “Edge” for the electrons to pile up against. This is the primary reason the plug resists thermal breakdown longer. This, and unleaded gas, is why you have plugs that last 100 K miles.

This FOG quote is how I understood the Iridiums to work. They have a much smaller electrode for making a better, more consistent spark. The exotic metals are used to give that tiny electrode more strength. The plain copper ones have a bigger electrode (which is less than optimal) because it wears away more quickly.

I recently replaced my stock/dealer plugs with Iridiums, and it does seem to run a bit more smoothly now. However, it may have run just as well with brand new standard plugs as well. I'm used to the Syclone and having to buy one-off parts or buying parts kits for V8s and using only 3/4 of it, so $8 extra on a plug change doesn't even faze me.

[SV Racing Parts]

Are CR8E are the correct OEM Plugs?

[alex.s]

yes

[Asspire]

Originally Posted by nbleak21

Yep, just from a maintenance standpoint alone, it makes sense to me. Just remember to use a dab of anti-seize

actually, do not use anti-seize, these plugs come with a coating on the threads already, using anti-seize can cause damage to the head

[jkv45]

Originally Posted by Asspire

actually, do not use anti-seize, these plugs come with a coating on the threads already, using anti-seize can cause damage to the head

Yup - that's NGK's recommendation.

NGK plugs (and all plugs with a silver finish) have a layer of plating on them to resist corrosion between the steel plug and aluminum head. A black-colored plug does not, and would require anti-seize.

Plugs with a crush-washer aren't good candidates for tightening with a torque wrench, and adding anti-seize can make over-tightening and damage more likely. With a crush washer you need to snug it down - but it doesn't stop dead like a taper-seat plug. I never use a torque wrench on a plug with a crush washer.

A plug that seals with a taper (no gasket/washer) is much easier to torque to spec.