Irridium spark plug gap?

[Trey]

I looked around for this, but can't seem to find it. I replaced the kit plug in my 4-stroke with the recommended irridium plug. The gap on these and platinum plugs is usually larger than a standard plug.
Anyone know what it should be?

Thank you for any help.

 

[xseler]

Don't mess with the gap on the iridium's.....they are pre-set and messing with them can flake off the iridium. It's good to go!

Good luck!

 

[KCvale]

Don't mess with the gap on the iridium's.....they are pre-set and messing with them can flake off the iridium. It's good to go!

Good luck!

Exactly correct, that's why they ship with a cardboard tube around the thread end, to protect it. The iridium part is just the little tip at the bottom of the plug not the grounded L arm cathode part but still, they are gaped perfect.

 

[Huffydavidson]

Why didn't you ask this question when you were standing at the parts counter?

 

[KCvale]

Why didn't you ask this question when you were standing at the parts counter?

He most likely got it on-line like I have been doing as local parts stores don't stock them and in some cases can't even find them in the computer to order 'em.

I e-mailed NGK tech support from their web site contact form about how to get them locally and this is the e-mail exchange from the form on, note everything on the form was based on make and model of vehicle not a cross reference:

-----Original Message-----
From: [email protected] [mailto:[email protected]]
Sent: Friday, September 06, 2013 12:07 PM
To: Info
Subject: NGK Form Mail

**** Contact Form & Tech Info Feedback ****

Email From: [email protected]
VehicleType: Motorized Bicycle
Make: na
Model: na
Year: na
Engine Type: 48-66cc Chinese 2-stroke
Comments: Your web site could really use a Search by Part Number ability.

I use BPR7HIX (5944) Iridium spark plugs in my little 2-stroke engines and praise them to no end but not only can my local auto supply house not order them they have no way to even look them up to compare it to your 'everything by machine' system.

Please let me know a cross reference or a supplier in my area.

Thank you,

KC Vale
KC's Kruisers http://KCsBikes.com
Phoenix, AZ 85021
USA

END OF REPORT


-----Original Message-----
From: MacDonald, Robert [mailto:[email protected]]
Sent: Friday, September 06, 2013 9:43 AM
To: [email protected]
Cc: Zdral, Kristopher
Subject: RE: NGK Form Mail

Hello,

There is not an alternative part number for BPR7HIX that would maintain the same attributes and still be an Iridium plug. This part should be available to order from NAPA, Orielly Auto Parts, Advance Auto parts, Autozone, Carquest. Also we have one of our largest distributors on the west coast at www.sparkplugs.com that you can order from.

Thank you,

Rob MacDonald
Technical & Training Specialist
NGK Spark Plugs U.S.A. INC. || http://www.ngksparkplugs.com
46929 Magellan Dr. || Wixom, MI 48393
OFFICE: 248-926-7104

-----Original Message-----
From: KC's Kruisers [mailto:[email protected]]
Sent: Friday, September 06, 2013 1:41 PM
To: MacDonald, Robert
Subject: RE: NGK Form Mail

Thanks Rob, I have a Carquest right around the corner from me and been asking them on occasion for a year to keep them stocked for me and they can't even find them in their system or anywhere else.

CarQuest
Quality Discount Aut6o Parts
1817 W. Peoria Ave.
Phoenix, AZ
602 944-2269

I have no problem paying $7 a plug + sales tax for one but paying shipping and waiting to order on-line seems silly when I have a local parts store right around the corner.

I know what the heat range number is, 7 is good here in Phoenix for the most part but we may need 8's when riding it 110+ degree heat for extended periods and 6's may be better for up in the mountains by Flagstaff in winter.

I think maybe NGK may have underestimated the market for a kick ass plug for these cheap 2-stroke 2-3HP engines is when this one item makes such a huge difference over the stock kit's LD Z4JC or even you own B-6L but nobody can even order them in local auto shops including the autozone right around the corner from me.

I know, it's an obscure item but could you let my local store know how to order them for me?

Thanks,
KC

---

Hello,

For the store to order this part they will have to contact their DC (** KC note, DC is Distribution Center **) with the stock number 5944 and have them ordered, they may be a special order item if they are not stocking them in the DC. Our distributors chose the parts that they stock and carry this is not something we have control over. If they are unable to order the plugs you may try one of the other stores in the Phoenix area.

Thank you,

Rob MacDonald
Technical & Training Specialist
NGK Spark Plugs U.S.A. INC. || http://www.ngksparkplugs.com
46929 Magellan Dr. || Wixom, MI 48393
OFFICE: 248-926-7104

------------

Now you know what I know about how to get these plugs local.
If just need one or two I suggest just going through sickbikeparts.com, especially if ordering other stuff at the same time, but if you are in an motorized bicycle active area or build a bunch it might be handy to get them local.

I have an Autozone, Orielly's, and a Carquest around the corner from me so I think I'll try his advice Monday as I put one in every new build right out of the box, speaking of which I have probably 50 or more new stock 2-stroke kit plugs if anyone wants them for $1 each in 10's or more.

 

[Trey]

Don't mess with the gap on the iridium's.....they are pre-set and messing with them can flake off the iridium. It's good to go!

Good luck!

Gapped it twice, finally to 55- did flake a bit, but works great.

 

[Trey]

Exactly correct, that's why they ship with a cardboard tube around the thread end, to protect it. The iridium part is just the little tip at the bottom of the plug not the grounded L arm cathode part but still, they are gaped perfect.

Mine came gapped at 35- no good, ran like an old sick dog. Went to 45- better, ended up at 55- runs great.

 

[Trey]

Why didn't you ask this question when you were standing at the parts counter?

I'm real surprised to hear you ask that man. How many times have you tried to explain what you're using after market parts for, to the confused salesperson? I don't have 20 minutes to spare every time I go in to get something. I finally ran out of patients. Even though that can be a good way to get a GasBike conversation started

 

[Trey]

Now you know what I know about how to get these plugs local.
If just need one or two I suggest just going through sickbikeparts.com, especially if ordering other stuff at the same time, but if you are in an motorized bicycle active area or build a bunch it might be handy to get them local.

I have an Autozone, Orielly's, and a Carquest around the corner from me so I think I'll try his advice Monday as I put one in every new build right out of the box, speaking of which I have probably 50 or more new stock 2-stroke kit plugs if anyone wants them for $1 each in 10's or more.

That's helpful info KC.
My local O'riellys carries them, but had to get one from across town.

 

[Trey]

It is a common misconception that; "Spark plugs come with the proper gap." This is untrue, and common sense dictates it so.
While you often can open em, verify the gap, and put em in, this is not always the case. Each spark plug usually has many applications, and the factory gap is not appropriate for every application.
Just a simple word of warning.

I thank you all for the replies

Have any of you installed an irridium plug in a 4 stroke Chinese kit engine? What gap did you use? What were your results?

 

[GearNut]

I have a CR7HIX in my EZM and I never gapped it. I was taught by my mentors as well as at MMI to never, ever gap an Iridium plug.
My EZM runs awesome too.

Hey, it's your spark plug. Do to it whatever you want to.
It's still a free world right?

 

[Trey]

GearNut- What's an EZM? You've given me lot's of good advice since I've been here and I thank you for it. I think you misunderstand me my friend. I do not know what to do with this plug- that's why I ask. My last post was just a quick word of warning, and correct- for standard plugs. But...
I'm sure that I've screwed up this plug (at least shortened it's life) by gapping it. The difference in the way the engine runs is night and day. The factory gap ran, but barely. I opened it up and now it runs better than the original plug. While I can see this type of plug shouldn't be gapped (flaking etc), I'm still interested in figuring out what's going on.
I don't have it in front of me, but I got the plug that is regularly recommended here (I may have even heard it from you- can't remember). I was expecting some sort of improvement, but got the opposite. Since I had to make a change to the gap to get performance, could this mean that my engine needs a valve job or something?

 

[KCvale]

I have a CR7HIX in my EZM and I never gapped it. I was taught by my mentors as well as at MMI to never, ever gap an Iridium plug.
My EZM runs awesome too.

If you feel you must tinker with the gap on an Iridium at least use the proper tool.

(from NGK's web site)

This is plug I use in the 48 and 66cc 2-strokes and never have to gap them and they have always made a performance boost.
http://www.ngk.com/product.aspx?zpid=9496

 

[Trey]

Thanks for the link KC.

 

[GearNut]

GearNut- What's an EZM?

Link to EZM: http://ezmotorbike.com/

I doubt that your valves need adjusting, but they are so easy to check and adjust that if you suspect that they need it, check them.

 

[Trey]

Thanks for that link GearNut. Now I see... nice. They seem to have pretty good prices too.
That mounting plate in the parts section reminds me of a design I have for a home made mobile 12v power station. Uses a horizontal shaft engine and an automotive alternator.
I will follow your advice and at least check those valves, it's about time I learned anyhow. Thanks.

 

[Trey]

Update. This plug has given good service.
Contrary to good advise given me, I changed to factory gap from -35 to -55. The pic isn't great. The plug is black/ brown, but tan/ brown on the core insulator, and white-ish on the electrode tip.

 

[KCvale]

Update. This plug has given good service.
Contrary to good advise given me, I changed to factory gap from -35 to -55. The pic isn't great. The plug is black/ brown, but tan/ brown on the core insulator, and white-ish on the electrode tip.

A year and a half and still sparking good, I love these Iridium's but WARNING!

DO NOT USE WITH HIGH COMPRESSION HEADS!

The NGK plugs are a tad longer than stock plugs.

This is great for a stock head, you get a bit higher compression as a bonus, but high compression heads already do that so the piston hits the anode at TDC.

It don't spark well with a 0 gap ;-}

I still use them in everything (with stock head) including the 49cc HS 142F 4-strokes now.
NGK 7544 (CR7HIX) Iridium
It wakes them up too with a bit more compression and better spark.

 

[Trey]

Thanks KC, you've added alot to this thread.