BP7ES spark plugs

I s anyone else having trouble finding NGK BP7ES plugs?

 

https://www.ebay.com/itm/BP7ES-NGK-...p2349624.m46890.l6249&mkrid=711-127632-2357-0

Best price I’ve found, I bought 8!

 

The only issue with that version of the BP7ES plug (the #2412 version) is that they have a fixed (non-removable) terminal nut, which will not fit inside the NGK plug caps. The original BP7ES ---- with the removable cap nut ---- caries a different NGK part number. Believe it or not, NGK has many different part number "versions" of many of their spark plugs, all with minor (or meaningful) differences from each other. Why this is done is beyond me, but I'm sure there's a legitimate reason for doing so.....

 

All these ones remove easily!
@chacal

 

Thanks, I ordered some. I'll see if they will work. It says fixed top nut in the description but they may be different.
I think NGK might have discontinued the ones we usually use in our bikes. I think a certain country was making fake NGK's but they may work fine.
edit- Okay I looked at the NGK website and they say use they BPR7ES. I am getting in touch with them to see about the fact that these are resistor plugs' I'll get back ASAP with what they have to say

 

Noahsxj.....well that it odd, the 2412's should have the fixed cap (that's straight from NGK themselves) but who knows what's really going on. Thanks for the update!

wkxj: the "replacement" BPR7ES plugs are resistive (5K ohms) so it present an issue with using the original (ore replacement) resistive plug caps, as it doubles the specified resistance specs for many of the bikes; however, it may (or may not) really make much of a difference in performance.

 

Maybe specs have changed over time, and certainly manufacturing costs would be lower for non screw cap items.
I wouldn't use resistor plugs with resistor caps, simply because higher resistance will cause the ht voltage to get higher before the spark jumps. This could break down the tci output stage. I stress "could", but of course we have loads of cheap, spare tci's around - don't we?

 

I did visually compare the 22+ year old plug that came out of my virago with the one I ordered from this eBay seller

they seemed identical, although I did not check resistance or ohms

I still have them, I’ll test them both when I get home work

if they are fake, and from this certain country you’re pertaining to, then I must say they are of very high quality!

 

I've been using NGK BP7ES plugs on a 82 Yamaha 650 Seca. I noticed these plugs are being discontinued and replaced with BPR7ES that I believe are a resistor type plug? My concern is that the plug wires caps are also a resistor type and might effect the control unit or the performance of the bike.
Thanks Will


Hello,

Thank you for your inquiry. If your bike has electronic ignition and not points and condenser using magneto system, the resistor plugs will be fine with no issues. The only other option would be a non-resistor racing series plug, R5671A-7. The difference is the hex is smaller (13/16” down to 5/8”) and the center electrode projection (center electrode depth into the combustion chamber) is shorter. BP7ES is 3mm and racing plug is 1mm.


So here's what I asked and their response.

 

According to NGK's cross reference material, there are several possible replacements for BP7ES from other manufacturers:
https://ngksparkplugs.com/wp-content/uploads/2020/10/Spark-Plug-Cross-Reference_2019.pdf

In my opinion, it is probably a better idea to convert to resistor plugs and a non-resistive cap (so just a boot, in that case?).

Therefore, the challenge is going to be finding a cap/boot that looks "correct" and will swap out without having to splice plug wires or replace the entire coil or anything drastic like that.

Does anybody have some good ideas for non-resistive replacement caps/boots that will work? @chacal ?

 

Also, I may be crazy, but I seem to remember somebody talking about removing the resistors from the caps? Maybe it was on the "what did you do to your Yamaha today" thread??

Seems like some pretty major surgery considering the caps seem to be a pretty solid molded piece of plastic. I would like to see a how-to if somebody has done it.

I may have a bad cap I could experiment with also. If I get anywhere I will share the results.

 

The longer (inner) caps on the XJ750 Seca had replaceable / removable resistors. The outer caps did not

 

OK, I see. I did cut open an NGK cap that tested bad and found the resistor in there. Definitely not going to be doing that to remove the resistor in any feasible way.

 

My caps just need a flat head screwdriver to unscrew the sparkplug gripper/resister stopper. Be careful to not lose the little flat disk.

 

Rooster, is there a technical name for that style fuse?

 

Resistor, special

 

The original caps had replaceable resistors. They can be removed and brass rod (cut to the proper length) used. Alternatively NGK sells non-resistor caps.

 

A look on the NGK website shows that the BK7ES is in process of being superseded. That means there will be a new plug with the required non-resistance spec under a new part number.

A look on Amazon returns this
https://www.amazon.com/NGK-BPR7ES-SOLID-Standard-Spark/dp/B01DMFHL5Q/ref=sr_1_1?crid=3EC9H9RVQR10V&keywords=NGK+BP7es&qid=1640730977&sprefix=ngk+bp7es,aps,83&sr=8-1

What seems to be a like-spec plug with modern features.
I'll do some more digging to confirm that when I have time.

Whatever you do, don't pay scalper prices for a BP7ES. There are a lot of profiteers out there who want to make us panic-buy when there is no need to.

 

It's just a normal carbon resistor without any wire embedded into it. I seem to recall that you had some in stock. I doubt that anyone is making them anymore.

 

On a completely unrelated subject, who needs some toilet paper?

 

)

 

I'm moving over to all resistor plugs on all my bikes, with NGK caps to suit (no resistors). NGK sell them with and without.
Means I get a new resistor every plug change.

 

I use Autolite 63 these are a listed as equivalent and are not too much .

 

Hey guys, I got my plugs in today. They are the 2412's . the end can be screwed off but they are made in Thailand as opposed to being made in Japan.
I have to say they look well made. I wont be able to try them out for awhile. The bike is going to take awhile longer to be ready to start up.
I might have to try out the Autolites as well

 

I like the Autolite plugs , when I had a Virago 750 this was the preferred plug on the forum and seemed to most to perform as well if not better than the NGK .

 

@wkxj NGK does manufacture authentic plugs in Thailand

 

Any chance you could link the NGK caps? I put my model in on their website and none show up. Only plugs. Thanks

 

Here's an example of the short right-angle non-resistor one, but it's out of stock.
https://www.gsparkplug.com/1x-ngk-none-resistor-spark-plug-cap-lzfh-black-8710.html

Looks like they no longer stock the longer ones.
I'll have to find some for myself, too.
At the moment it's not a problem and I can simply remove the resistors from resistor caps.
This is their entire list of non-resistor caps...
https://ie.gsparkplug.com/ignition/spark-plug-caps/none-resisted-caps