NGK BP 7ES RIP

Fast Eddie said:

Ash... might be worth trying a new pair of plugs... you may find a performance boost...!

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Nigel the good thing about the Joe Hunt Maggie is the big fat spark and the plugs run so clean even after years of running them, I was doing some maintenance on the Norton today and as usual I pulled the plugs, took one look at them and put them straight back in, there is no wear or anything wrong with the plugs and the bike is performing the same as the first day I put them in, the plugs have about 35k miles on them now.
I think my Norton is a freak as its always been reliable and has always been good with plugs in over 44 years I have owned it, my Norton just don't like other brand plugs and has always ran better with the Champions.

Ashley

I hear you Ash... but for the £4 it‘d cost, it might be worth a try.

Even when dynoing race bikes it’s kinda well known that you’ll get the best figure with fresh plugs. Even if the ‘old’ ones were new at the start of the day.

At 35,000 miles, you just don’t know how much gradual performance loss they may have accumulated.

In a feeble attempt to steer this thread away from certain disaster in Jerry’s absence, I like the BP7ES because it works in my airhead and Guzzi. It’s nice to just stock one plug. Silly reason, but it’s true.

Political posts have been deleted.
No more, please.

There are a lot of counterfeits out there, especially NGK Iridiums. The only benefit from Iridiums are a longer life. Best spark is from a bog standard copper cored spark plug.

That’s not my understanding....

Iridium plugs have tiny electrodes that require less voltage to provide a given spark. OR create a stronger spark with a given voltage.

That said, my T140 does seem to run better on standard plugs, so maybe it’s all bollox ?!

I thought with a wasted spark ignition, iridium plugs are best as the spark alternates from firing centre electrode to earth arm...then earth arm to centre electrode

I don’t always believe what I read. Just did a quick Google and this came up. I think there is more stuff out there if one is interested. I think it all academic as they all work. Just I am suspicious of marketing as a means of prising my hard earned!

Sorry, read that and have to wonder who it's aimed at? 'Forced to make a 'difficult' decision....' Really??
'The metal should also not get too hot' It's in a combustion chamber, ffs... what else can it do?
Yes, there's a debate but that shoots itself in the foot IMHO....

Are BP7EY still available. Only difference is the groove in the centre electrode.

olympus said:

I thought with a wasted spark ignition, iridium plugs are best as the spark alternates from firing centre electrode to earth arm...then earth arm to centre electrode

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No, that sounds wrong.

With a dual output coil, one of the plugs sparks from centre to earth; the other plug sparks from earth to centre. That doesn’t alternate, or change until you swap the HT leads or plugs over.

The point I was trying to make is that with one of the plugs firing from the earth arm to the centre electrode iridium plugs are best as both components are made of this material

RoadScholar said:

I went to my local NAPA to get a box of BP 7ES, amongst other items. I got the box I was looking for, but the manager told me that these had been superseded by BPR 7ES. Those of you who run with EIs may want to consider Denso, Champion or Bosch replacements, or swap out your 5K caps for zero K caps.

Best.

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FWIW, NGK BP 7ES, or 1034's -- rockauto still lists them. I put 10 in my cart, and it took the quantity, so i'm assuming they have plenty in stock. $1.87 each + S&H

I just picked up 4 from where I used to work, £0.96 each plus tax. It’s handy being able to buy at cost still.

Fast Eddie said:

If the Denso’s work for you then keep using ‘em!

However, at the risk of being a nerd here, it’s not really relevant to compare performance of standard plugs of one make to iridium plugs of another make.

FWIW I’m a fan of iridium plugs too and am also currently running Denso IW’s in my Commando, but I also use NGK Iridiums and cannot tell any difference.

Interestingly though, I have a T140 that I am convinced runs better with standard plugs !

Is anyone aware of any logical reason for this? Or am I just kidding / confusing myself (again) ?

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I race with the Denso IW27 and I will stick with them. But I am equally sure another plug of the same heat range would work.

Using a standard plug does have 2 strands of logic behind it, one, you simply don't need them unless you want to leave them in for 100K miles.

For normal use you should expect no benefit from precious metals other than potential longevity! But....if you are using a redundant spark EI, and most of us are, the spark discharge is a different polarity on each plug and precious metal erosion from the small centre electrode on the one plug may eventually cause a problem! Jim Comstock explained this a lot better some time back!

I also used N4G years ago on the recommenation of Champion, they were great for a race bike too and avoided the cold fouling that was always an issue with race plugs in those days.

Scout63 said:

In a feeble attempt to steer this thread away from certain disaster in Jerry’s absence, I like the BP7ES because it works in my airhead and Guzzi. It’s nice to just stock one plug. Silly reason, but it’s true.

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It isn't a silly reason, it allows you to keep a better stock for when you need them.....

Champion N4G for me in all my britbikes

EstuaryBoy said:

Sorry, read that and have to wonder who it's aimed at? 'Forced to make a 'difficult' decision....' Really??
'The metal should also not get too hot' It's in a combustion chamber, ffs... what else can it do?
Yes, there's a debate but that shoots itself in the foot IMHO....

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There is a great deal of difference between hot and too hot.....which is why plugs come in different heat ranges!, use a plug that is 'too hot' in a race engine and you will regret it big time......use a plug that is 'too cool' in a road bike and it will foul up!

The metals may differ but the main difference in a hot or cold plug is the insulator shape, the intent is to allow more heat to dissipate to make the plug itself run cooler or hotter depending on application. Too much heat......and you willl get the electrodes overheating.....

SteveA said:

There is a great deal of difference between hot and too hot.....which is why plugs come in different heat ranges!, use a plug that is 'too hot' in a race engine and you will regret it big time......use a plug that is 'too cool' in a road bike and it will foul up!

The metals may differ but the main difference in a hot or cold plug is the insulator shape, the intent is to allow more heat to dissipate to make the plug itself run cooler or hotter depending on application. Too much heat......and you willl get the electrodes overheating.....

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I hear you but we're talking differing 'heat' ranges.. yes a plug may be 'cooler' than another, but it's really 'not as hot as'... no? To me that article seemed a bit patronising.... perhaps it's lockdown getting to me

With a dual output (dual tower) single coil, one spark fires from ground electrode to centre electrode, and the other spark fires the other way from centre electrode to ground electrode.

So for these coils, the precious metal tip on only one surface will only be beneficial on one side of the bike.

I like Densos, as I have a concern for the NGKs and Champions being counterfeit.

The VW22 has an iridium centre electrode and platinum ground electrode, so to me is a good candidate for dual output single coils.

The IW22 has an iridium centre electrode and nickel plated ground electrode (same as plug housing) so is ideal if you are running two coils. Perfectly fine for a standard two coil setup.

The other solution would be to swap plugs from left to right whenever you take them out for cleaning or inspection.


Denso have started doing a twin tipped iridium plug (they call it the TT) but it is not yet available in our heat range.

I also checked NGK a while back - looking at their double platinum and the new ruthenium plugs, and they didn’t have a suitable plug for our bikes at the time.


This is not a major problem, it’s purely sweating the small stuff.
But I do think it’s good for people to understand how their ignitions work and that if you have selected and paid extra for precious metal plugs (like iridium or platinum) believing there is a benefit of longer service life and slower electrode erosion, you are made aware of how a dual tower single coil works and that you may be foregoing any benefit.

I know several very reputable companies that ship the NGK ‘R’ plugs as part of their single coil packages.



This has nothing to do with wasted spark ignition, where you get a firing plug on both sides whether you are on the combustion stroke or not.
That’s just the behaviour of most electronic ignitions versus standard points where you only get a spark on the cylinder that is on the combustion stroke.