Thanks for the input/assistance.

Correct me if I am wrong; don't our bikes (well at least my F4i) come with iridium plugs already? I was just looking at the service manual and it listed two replacement part numbers (NGK IMR9A-9H and Denso IUH27D) and they're both iridium plugs. So what's with the "standard nickel" plug you mentioned? Why would I want to put 4 of those in? Just to save a few bucks?

Finally, once I put my Power Commander in this spring - would it be beneficial to change the plugs? I currently have about 13,000 miles on the bike/plugs so I don't think there would be a problem leaving them in there (unless they're NOT iridium).

Thanks again,
Joe

 

If your bike comes with iridium plugs OE, that's great, that means the manufacturer is giving you the best plugs you can get. Standard nickel plugs (also incorrectly referred to as "copper" plugs) are your basic $.99-$2 spark plugs you can pick up at your local autozone - it is what most vehicle manufacturers install OE because they are least expensive. Iridium's are the high performance plugs, only some manufacturers install these OE, but usually, you'd install them aftermarket if you want optimum performance.

Standard nickel plugs will last, on average, around 30k miles. Iridiums should last between 60k-80k on an unaltered motor. You'll want to take the plugs out about every 30k miles or so, check the gap, regap if necesary, and make sure everything is running ok. Otherwise, you've got quite a ways to go before your plugs should need to be changed.

 

I've bought from you guys a couple times in the past.....you have an excellent site and I felt the turn around on orders was quick.

It likely varies with engine/combustion chamberdesigns, but on CR9E equiped bikes (my assorted Kawi's), I've found measurable gains from CR9EK's (1-2hp, as measured against a fresh CR9E). Yamaha switched to this plug in the early 2000's. Another forum I am on, a guy is going to throw IX's into the mix and test.

 

That's interesting...How long are the CR9EK's lasting you in comparison to the CR9E?

 

If I keep a bike long enough I'll let you know.....

I change plugs with every valve adjustment as it such a pain to do them at a different interval...so 5-7K...Can't say as I've ever "worn out" a plug in a bike to the point of re-gappingor replacement yet...probably just what you like to hear....HA.

Ever have problems substituting a denso plug in something that was NGK from the factory?In my experience, anything that came from the factory with NGK won't run right on anything else....from my weed-eater to my sleds/bikes/cars. Denso is no small company, so I am sure they make quality stuff as well.

 

Reason I asked is the technical thread I directed everyone to talks about multi-ground plugs. In summary, multi-ground plugs were designed for a specific engine type that requires the electrodes to be placed off to the side. because the ground strap is so short, they have to create multiple grounds because just having one would wear the plug out too fast. There's many gimics out there and plug manufacturers that push and promote multi ground plugs for all vehicles, whether the engine was created for their use or not, and their marketing even stretches so far at times as to make you think that multi ground=multi spark, which is false. Multiground plugs aren't meant to be run in engines not created for thier use. In some engines, they will run fine, but won't increase plug life by any means. In other engines, they'll run horribly.

So your talking about changing over to the CR9EK peaked my curiosity and I wondered how long the plugs were lasting as compared to the single ground. Sounds like you may have figured out that that engine runs better with a multi ground before Honda did.

Denso does make high quality products. From a technical aspect, their iridium plugs are the most technoligically advanced in the industry. But when it comes to the standard plugs, if you find a brand that works better than others in an application, stick to it - whether it happens to be the factory plug or not.

 

I have two guesses:
1. that it gets the point of ignition deeper into the chamber...so some how improving the flame frontpropagation.
2. Having two electrodes lets the spark "choose" the best place to jump...again, helping ignition of the mixture.

In any case, I love your site, and will be back to purchase more....right now I am stocked up...but in a couple months will need more for various vehicles.

Any kind of a coupon code for your new friends here at CBRforum to enter??

John

 

I will be hitting you up within the next month.

 

uhh, bringing back an old post, but are you guys gonna run any other specials on spark plugs?

 

I want some Denso iridiums for my 06 f4i how do I order for a great deal? =)