Iridium spark plug are NOT forever..

[TownsendsFJR1300]

So....what spark plugs should I replace my OEM ones with?

Either.. This thread was to point out that Iridiums do NOT last forever, which was most (I believe/read) thought.

I'll probably go back to the stockers in another 10,000 miles..

 

[Cali rider]

There was one thread in which the Iridium plugs caused poor MPG. That was the only negative thing I've heard about them until this post. I know I got over 20k miles on my OEM stock plugs, and same thing, only changed them not because they failed, but because I wanted too. I think the manual says every 8000 miles.

Kenny, that was me about 4 years ago. Funny as the failure is similar in that it happened quickly with a spark plug that is supposed to last quite a while.

Here is the thread: http://www.600riders.com/forum/fz6-technical/44482-poor-mpg-things-not-always-they-appear.html

 

[IanHoots]

So....what spark plugs should I replace my OEM ones with?

I would recommend any plug that is installed and maintained properly. Choice of brand is a personal preference thing, but motorcycle plugs generally narrow our choices down a bit.

In my earlier post I forgot to mention what I believed was the root cause premature spark plug failure in the Subaru. Upon close inspection the plugs appeared to have a conductive track across the insulator. Fuel quality is a significant problem in my part of the world, quite a lot of Jap and Euro engineered engines struggle with tuning in Australia. It has been common practice for an AU engine management package to try and deal with the fillers contained in fuel and stale unleaded. This doesn't seem to be as bigger issue in other countries.

Yes, I agree with FinalImpact, regular inspections of plugs is a good indicator of engine tune. All the talk about sandblasting and re-gapping only really becomes an issue with an engine that is run outside of a good air/fuel ratio. That's not normally a drama for an FZ6 engine thats well looked after and given a spanking every now and then to clean out the carbon.

I chucked iridium NGK in my FZ6 because I'm lazy and don't want to change them too often

 

[TownsendsFJR1300]

Funny as the failure is similar in that it happened quickly with a spark plug that is supposed to last quite a while.

Here is the thread: http://www.600riders.com/forum/fz6-technical/44482-poor-mpg-things-not-always-they-appear.html

I remember reading that thread way back. Thanks for the link and reminder.

That just re-affirms what'l go back in my bike when due..

 

[FinalImpact]

I would recommend any plug that is installed and maintained properly. Choice of brand is a personal preference thing, but motorcycle plugs generally narrow our choices down a bit.

In my earlier post I forgot to mention what I believed was the root cause premature spark plug failure in the Subaru. Upon close inspection the plugs appeared to have a conductive track across the insulator. Fuel quality is a significant problem in my part of the world, quite a lot of Jap and Euro engineered engines struggle with tuning in Australia. It has been common practice for an AU engine management package to try and deal with the fillers contained in fuel and stale unleaded. This doesn't seem to be as bigger issue in other countries.

Yes, I agree with FinalImpact, regular inspections of plugs is a good indicator of engine tune. All the talk about sandblasting and re-gapping only really becomes an issue with an engine that is run outside of a good air/fuel ratio. That's not normally a drama for an FZ6 engine thats well looked after and given a spanking every now and then to clean out the carbon.

I chucked iridium NGK in my FZ6 because I'm lazy and don't want to change them too often

Thanks for sharing and well said. These are deturned race engines and they want what they want to be happy. Yes, they will run on whatever cr@p you pour in the tank but they run better on some blends than others...

These are scary clean even to me as there is nothing to read at 3000mi. They are burning clean even with the AFR of 13.0:1. Bike runs great and performs well. It is breathing much better than it did stock. Open 2 Bro and catless....

CR10E @3000 mi after S1 header, ignition advance, Bazzaz ZFI tuner....

This engine stays clean inside in part to how its operated, the tune, and fuel quality. As stated increased velocity from reving it helps this. That doesn't mean I ring its neck tho.

 

[TownsendsFJR1300]

Now why do you like the single ground more than the stock dual ground? (I'm sure you posted it somewhere).

 

[FinalImpact]

Gap is more stable over time. Duals wear on the side quickly changing the gap....

 

[TownsendsFJR1300]

While on a Yamaha OB engine forum I frequent, the topic of spark plugs came up and this link was posted.

Link from NGK: https://www.ngk.com/glossary/8/spark-plug/M

Specifically:

"Caution should be made in selecting a "high performance" plug. If your car came OE with a multi-ground plug, your engine will likely wear through single electrode plugs, especially Fine Wire plugs, at a rapid rate."


IE, exactly what I experienced....

 

[FinalImpact]

Nice post. That supports what both of us have seen in the real world.

Keeping in mind that the waste spark ignition system on these bikes is firing 2X per power stroke hence the increased wear rates compared to say an R6 with individual COPs...

FWIW The nose length is not an issue using none "K" plug. Also the FZ6R went to the CR9E plug IIRC. Potentially due to the increased gap early on which equates to increased emissions.