Spark plug question...

Ok, I searched high and low for answers on this one, but I ended up more confused I think. LOL

I know the recommended plug is the NGK IMR9B9H. However, I know the Denso IUH27 is also an option.
When I was looking at spark plug cross references, the Denso had a lot more cross references than the NGK. In particular was this one: NGK CR9EHIX9
It is an iriduim plug, and lists the Denso IUH27 as a cross reference.
Does anyone know for sure if this will work? I only ask because I've found sets of this NGK for as little as $30 shipped, versus $40+ for the IMR's.

 

According to this NGK decode page NGK sparkplug symbol code decode it should be fine, all important dimensions are correct.

An Iridium tipped plug should last the life of the engine. If you don't suffer from misfires or ignition related issues, whip them out at the prescribed interval, inspect the ends & gap, inspect the bent prod carefully, as these have been known to seperate through poor welding.
If all is OK, then clean the threads, lube with copper grease & put them back in. Job done.

2-stroke used to degrade their plugs, but 4-stroke with unleaded don't so long as the A/F ratio has been within normal tolerances.

You can always take a plug out & check it against a new one, if your not absolutely sure.

 

IMO cheaper is not always better... Iridium tips from Autoparts store(i.e. O'Riley's, Advanced, Napa, or Auto Zone) are about $10.00 to $15.00 each, also if here is a problem you can return to them (usually no quesions asked) and get a different one. I would let my fingers do the walking and call all within about 20 mins of the house and ask how much and if they have on one and then make an educated decision as to what to pick.

I replaced mine a few weeks ago and found that the Honda dealer was by for the most expensive at just under 20.00 per plug. I ended up going to advanced and paying $8.00 each for the NGK IMR9B9H. (I had to order and wait about 3 days to get them) I also get them at dealer cost and work at a moorcycle shop on my days off from my day job.

 

If you want to know about sparkplugs, go over to Home to the learning center. There is also cross reference charts and anything you want to know about plugs. Great site for plugs and learning.

Platinum plugs have basically been replaced with Iridium. A fine wire plug will/should work better for startup, idle and instant response if everything else is adjusted/mapped on your bike engine wise. If the cross reference shows the Denso IUH27 as a replacement it should be fine. Once you learn about the numbering system of plugs(different between USA & Europe) you can buy what ever you want/need.

 

I believe if you use copper-slip (grease) on a two stroke, you affect the heat range on the firing plug. That being said, I believe it would affect a "plug-chop" thus rendering being able to read the plug, "useless."

I stopped greasing spark plug threads years ago, talking to people in the aviation biz, is another story. They still do...Think about it, does the manual say, "grease the threads?" Dont belive it does...

 

I put a bit of Anti-seize on the threads of spark plugs. It goes in & comes out much easier. I also use this stuff on axles. This allows them to thread and slip on and off easier, and keeps minor rust from building up.

 

I use dialectic grease on spark plug leeds though. Use anti-sleeze on axles too, in addition to grease.

If you grease the threads on a spark plug, think about this; its going to change the torque spec on it, not that I rely on a measuring tool to fire them plugs in there, just my trusted calibrated elbow.

 

Well the standard way to fit new plugs is hand tight plus 1/8 turn with spanner/socket !

 

Was in the pits and was watching a TZ125 racing fellow fit a new plug in his bike. He had a torque wrench dial up and used it to install the new plug. Later that day I told an employer that I was working for at the time, he said it was good because "that fellow had no feel."

There is a crush washer built into most plugs, you can "feel" when it kind of smears the washer at that point, I may give it an extra cunts hair ie 1/8 of a turn, ts a feel thing, nothing but a "g" thang baby...:afro: :drinkers: cheers mate

 

Yep spot on, the crush washer is the reason for the 1/8 & most will give you 4 tightening a before that washer is fully crushed ! :smile:

 

Thanks to all for the input. I was mostly curious about the plug itself though. LOL
I've been wrenching on cars since I was 10, and motorcycles for the past 6 years. So changing and tightening the plugs is not an issue.

And while cheaper is not always better, it's not always sub-par. that was my main concern with the CR9 plug. It is an iridium plug, meets all the dimensions, and is made by NGK. I just couldn't really see the difference between the two, other than the cost and part number. If I've found another alternative plug that works, I can't really see the downside.

 

I'll probably end up trying the CR9's, at least, to see how they do.
Also, regarding plug life, I haven't had an opportunity to change everything on the bike that I've wanted to, yet. Usually when I get a new car/bike, I do a complete tune-up, regardless of what the previous owner says was done recently. Just something my dad taught me.

 

A little more digging on the CR9's and I FINALLY found something related to the VFR. LOL
Found this review for them on Amazon:
NGK is a great brand and I use their spark plugs in all my vehicles. I recently replaced my spark plugs in my 2001 Honda VFR 800FI. This is a good solid replacement plug. I am wondering about the longevity but I know the Iridium plugs in my car will last at least 40k. My manual states to replace the plugs after every 12k but the originals were standard Denso plugs. These are much better.

 

Ok... I'm going to keep researching this stuff, and hopefully figure this out for sure. LOL
Found a huge cross reference chart, and this is what I found:

Denso VNH27Z --> NGK IMR9B9H

Denso IUH27 --> NGK IMR9A9H --> NGK CR9EHIX9

And from everything I've deciphered on the NGK numbering system, the A, B, etc... just refers to some firing end construction. Per NGK "Special Code".
So, based on that information, it just looks like the firing end might be a little different? All iridium plugs, otherwise.

Sorry for all the posts, but I like to have as much information as possible, if a disagreement came up. :crazy:

 

And let's beat this down a little more... otstir:

I found some actual pics of the different types of NGK I listed. I really can't see much of a difference here. About the only thing I can spot is the terminal, and even that varied between pictures.

 

Oh forgot to mention that NGK CR9EHIX-9 is what I use in my 5th Gen, so its fine the heads are the same !

 

Seriously? You just NOW chime in? Where the F were you this morning?!:chaingun:

:wink:

 

yeah well I was having a brain out moment, yesterday & checked what I'd installed in mine lastnight :smile:

 

LOL, fair enough. I seem to have those moments every day.

It's just odd that they don't cross reference though.

Actually, scratch that. It makes perfect sense from a marketing stand point.

 

Just bought a set of the CR9's off flea-bay for $26.26 shipped.
Yeah, I'll take that over the $45 from my local parts store anyday.