Iridium IX Spark plugs 449-511

ive used iridium plugs in my two strokes for years,as a matter of fact nealy everyone who races over here that i know uses them. just make sure the heat range is correct.

Hey! Do you believe Amazon or me!!??!

Lol. I posted it too soon. I think I'll house keep that post.

Haha, I have info like that on my info tab in my profile.

I have the iridium plug, not noticeable difference vs the stocker. Maybe it helps but who knows really.
But i had the cover off so why not upgrade?

Think of them as a higher quality spark plug. They give you a consistently stronger spark over a long period of time. It's like adding a standard plug in every time you ride. More hp, no, but smoother idle and easier starts, yes.

Have used the NGK Iridium IX for years in all my 2 strokes.
Never ever fouled a plug, they keep working for a very very very long time.
Actually never had a problem whatsoever with them, Can recommend to anyone.

Should be better for 2T as they've gone to a lot of trouble to reduce carbon build up on the insulator.

Hey, you are right. My bike ran real smooth with iridium. Cosmo approves of this spark plug.

Love NGK products!!
In over 30 years working with all sorts of mechanical things, I have only ever had 1 dead plug out of a box.
Can't say the same for any other brand I've dealt with.

Okay so I am changing my factory plug of my te449 out to an Iridium plug ( I seen a CR9EIX on the shelf in a part store and mad an impulse buy). I noticed that the plug that came out of it (CR9EKB) is a dual prong plug and the CR9EIX is a single prong. Does this have any effect? Why is the iridium a single prong?

I would think the twin earth standard plug has two prongs to extend the life of the plug.

Electricity is lazy, it will travel the path of least resistance.
When one electrode wears a little, the spark will shift to the other closer electrode until it too wears.
The spark will shift back and forth until the plug is worn out & replaced. (They don't fire both at the same time)
The Iridium plugs have long life electrodes, so a single set should outlast a conventional plug with twin electrodes.

That's how I see it anyhow.

Okay so I changed the plug out to the CR9EIX. The first thing I noticed was that the plug never seems to tighten? The plug screws in to the point where it feels like the gasket has bottomed out ( and should get another 1/4 turn). Unfortunately the plug seems to keep turning after this point and never snugs up.

After farting around with threading the plug in I tried starting the bike. It seems to run okay but almost sound like a tractor. Kind of a strange pounding/knocking noise. Throttle response was a little funny to. I swapped the plug back out to the factory one and it ran normal again. Also the factory plugs just feels much better when tightening it.

I tried this experiment once more and got the same results. I am a little leery to try threading the iridium plug back in as I do not want to mess up any threads.

Doesn't sound like it was all the way home then....

Looks like you have the right numbers....

Isn't the part of the iridium plug that your socket fits onto slightly thinner (top to bottom) than the factory one? I think I read in another thread that some guys were having problems getting their sockets all the way into and past the gasket in the valve cover. You may be running out of socket before the new plug is tight. See if you can borrow a thinner, or spark plug specific, socket. My harbor freight color coded deep well sockets fit just fine. I'm running the iridium plug.

Good catch, I've had that same problem before.

Looked on zip-ty web site. Cant find it. Do you sell these?

Okay slightly silly question but could I simply install the spark plug with the valve cover off? I have to remove it to put the Zip-Ty Oil Recirculation system on anyways.

We do, sold one today.

Yes.