Copper v. Platinum v. Iridium

The resistor plug shows a large area of ceramic conductor/resistor (5K Ohms) on their web page. I'll see if I can find a picture of the non-resistor plug to see if it shows how the two parts join.


This one has suppression, rather than being a resistor plug. It has a paste joining the two parts of the electrode:


And this site seems to have the best technical information, but looking at the cross section of the standard plug, it looks as if it might have been simplified as there are steps in the insulation which refelct nothing in the electrode.

http://www.ngkspark.co.nz/sparkplug_tech.php#

[EDIT - more info]
I found an online patent which explains more about the construction of a plug at
Patents Online
which refers to :
"The resistor is made of a glass mixed with a conductive material (such as carbon black, metal and the like), where blending (proportion) of the metal is not considerably high. Thus, joining the resistor directly to the metals {that is, the center electrode and the terminal metal fitting} is very often of difficulty. Therefore, a conductive glass seal layer which is made of a mixture of metal (in plenty) and glass is conventionally interposed between the resistor and the center electrode, and between the resistor and the terminal metal fitting, for improving joint strength."

This picture shows a solid copper plug with the join much higher in the plug.

I'm not sure if this has added much to the discussion, but at least we have more pictures...

 

"The resistor is made of a glass mixed with a conductive material (such as carbon black, metal and the like), where blending (proportion) of the metal is not considerably high."

Hmmmm...sounds similar to the way the old style non-metallic core spark plug wires were made. And they wore out (conductively) over time. And, of course, the resistors in spark plug caps wear out as well.

 

I put iridium in my 1986 Maxim X... It starts first time no choke... I can feel more power maybe since they are new plugs? ... I am not an electrician but I had great results...



Denso IX24 NGK DR8EIX: http://www.maxim-x.com/sparkplugs.html

 

Do you possibly know which ones you put in? I was going to get some but the guy at the auto parts store didn't know which ones I'd need... I'm curious to see if they make any difference...

 

Seriously? Were you able to start without choke before this plug change? Did you change anything else at the same time you changed your plugs. Not to sound like a naysayer, but it seems to me to go completely against many laws of physics for a simple spark plug change to affect your cold starting ability and give you any noticeable power gains. The only thing a better plug could do is improve the timing and burn rate of your fuel, which could net you maybe a horsepower or two, but would more likely improve fuel economy in a more noticeable way than HP.

That is, unless you had some plugs that weren't firing properly before the change. In which case, you didn't see a performance "gain," you just got things back to where they should have been, anyway.

Not sure about your bike, but I thought all of these used the NGK BP7ES. Whatever your bike uses, Advance, O'Reilly, Autozone, any of those places should be able to cross-reference your stock part number to other manufacturers and style of plugs that meet the same spec. Just make sure you gap correctly!

 

Mine uses Dr8es-L, i asked the guy at orielys and he said the computer didn't show any iridium replacements, he was probably being lazy and didn't want to cross reference...

 

Yeah... they do that. When I find a guy like that I make it a point to tell him I'm waiting for someone else to help me. I don't even fuss with them. They aren't worth the time or the extra air-breathing required. That's just pathetic. Probably ignorant to the ability to do that and too lazy to care.

 

The Denso Iridium IX24 will fix you right up.

 

Thanks for the info!

 

Glad to help. BTW, don't try to gap them. The center electrodes are fragile and DON'T need to be regapped to the original specs anyway.

 

I can confirm that the DENSO W22EP Platinum plug I use has a DC resistance of 1.7 ohm; pretty conductive and straight-thru to me.

According to my a$$, my bike idles and runs smoother with these plugs.

 

Same here for everything I've run them in. In my own bikes and customers' as well.

 

Forgot to mention that I also installed a performance K&N filter when I installed the plugs... My oversight.. http://www.amazon.com/YA-7080-Yamaha-Pe ... 797&sr=1-1


http://www.maxim-x.com/sparkplugs.html
Denso IX24 NGK DR8EIX
http://www.amazon.com/NGK-DR8EIX-Iridiu ... 450&sr=1-1

 

THAT would be your performance difference. Even the few anecdotal cases I've read don't really lend much credence to the idea that plugs actually help. A) If you replace bad plugs with any goods, you should see *an* improvement. B) I'd like to see someone who had a bike for years, used regular plugs time and again, then suddenly changed to something else and noticed (or, more preferably) *measured* a performance improvement. C) There are as many, if not more, anecdotal cases that there was no change. At all.

 

All plugs vary. Some plugs have an intentional amount of resistance, often called "suppression" by marketing geniuses. While that term is indeed accurate (for once for marketing folks) it comes with a caveat: you lose energy in the suppression that will never get to your spark. Law of conservation of energy and all. If you want suppression, shielded cables and ground isolation for sensitive components is the correct way to do it.

Also, if the plugs are old, the resistance could change. It could go up or down. Depends on how they are aging and/or what style they were to begin with.

 

Question Gentlemen. I have been reading in this forum about NGKBP7ES and NGKBPR7ES. It seems that the "R" resistor plugs should not be used in the XJ's. To be honest I'm not sure what I am running. My bike starts and runs. Ok to the question, I have a Yamaha manual for my 1983 XJ750K Maxim. (here in Canada) and it says to use "BPR7ES NGK or W22EPR-U ND." Which should I be using? The PO had the plug caps and the ignition coils replaced, the shop also installed NGKBPR7ES. I have owned the bike for 10 years now and I normally get what the manual told me to. How can I tell if the cap is a resistor cap or not.
Thanks for any input.

 

The standard caps that are installed on the83 XJ750K Maxim are resistor caps. That is why the bike uses NON resistive plugs. If using resistive plugs change your caps. Len, chacal, has them. I'm running E3's in my bike and they do what I want! the ideal plugs would be the same type used in marine and small aircraft applications. They have no ground strap to wear out. They fire to the outer ring. I have some for my boat will post picture of one later.

 

Thanks for the reply, Ground-Hugger. Does that mean the Yamaha manual is incorrect by recommending the resistor, BPR7ES plugs?

 

Yes it is because it doubles the resistance from 5 ohms to 10 ohms which cuts down the strength of the spark. Since the spark is not that strong in the first place it could cause a problem with fouling easier. So in order to maintain the 5 ohm resistance required for optimum operation you need to switch to a NON resistive cap.
Since the BP7ES are no longer available in Canada I have opted to go with the more expensive E3 plug. I am very happy with them as I do not need to use as much choke when starting and in most cases, warmer weather, do not need any choke.

 

So I just pulled my plugs. I had bought Champion RN9YC last time. Bike works good. They are over a year old, so I am getting new ones this week. Question: Who makes the "E3" plug? How much effect will the wrong (resistor plug) have on the running of the bike? Are there any visible ways to tell if there are resistor caps on the bike?
Thanks