Iridium Spark plugs

Reunited Chris

Reunited Chris

Senior member
Location
Sydney
This subject may have come up before, apologies if it has.
Since NGK no longer produce BP8ES plugs I wondered if switching over to Iridium plugs would be the go, I know they're more expensive etc.
I have them in my Benelli's and they work and last fine, 80,000 klm.
Would they have any adverse effect on the Ignitech ignition?
The particular Iridium replacement for the BP8ES is Denso IW24.
 
Reunited Chris said:
This subject may have come up before, apologies if it has.
Since NGK no longer produce BP8ES plugs I wondered if switching over to Iridium plugs would be the go, I know they're more expensive etc.
I have them in my Benelli's and they work and last fine, 80,000 klm.
Would they have any adverse effect on the Ignitech ignition?
The particular Iridium replacement for the BP8ES is Denso IW24.
Click to expand...
A quick search here will answer your question
https://laverdaforum.com/search/26029/?q=Iridium&o=date
 
Reckon that they should have left that Dam iridium buried but then again what would I know right
I mean everyone who has even a minute level of intelligence would understand.. god dam it so why reinvent the wheel… just quietly Tom’s mate tried it and they failed miserably.
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when I first modified the motor on my RGS Executive to overbored 1200 cylinder barrel, high comp J&E pistons, Carillo rods, etc. I used a local dyno to dial in ignition curve and the carb jetting of the Mikuni 36 mm flat slides. I had fitted Iridium plugs as part of the modifications.

when we hit the max result on the dyno after quite a bit of fiddling, the dyno operator suggested I try replacing the Iridium plugs with good old basic NGK. I had a couple of sets of NGK B8ES, I burnt my hands swapping out the plugs with the bike was still strapped to the dyno, then the bike was run again. Only change was the swap back from Iridium plugs to NGK B8ES. The bike picked up TEN horsepower (actually about 9.6 but close enough) with the plug change. I saw it with my own eyes. No idea why, but my personal experience on a modified Laverda triple motor.

I didn't know that NGK no longer supplies the NGK B8ES as indicated in the earlier post on this thread. What about the resistor version, or is it gone as well?
 
Resistor version of the B8ES is still available. I have been told but have not tried it yet, that you can unscrew the top of a resistor plug and the resistor will drop out. You then need to replace the resistor with a piece of metal rod.

I don't have any resistor NGK plugs to see if this is true.
 
Iridium plugs are designed for longterm usage and the iridium tip is hard wearing to maintain a consistent gap over high mileages. However, the downside of that is that the spark isn't as strong as a copper electrode plug, so will not be as efficient HP wise with a high compression engine. The most efficient plug type is the silver electrode, which gives a stronger spark than copper.
 
Using BR9ES in Oz - easy to find. Just went from resistor caps and 9ES to non-resistor caps and the Rs, so not sure I need to think about changing to anything else.
 
I rode 10K kilometers with NGK Iridium plugs on my formula 650. Never one stroke wrong.
Next year I try them on my Harris 600 racebike in 10mm modification.
 
Otto said:
I rode 10K kilometers with NGK Iridium plugs on my formula 650. Never one stroke wrong.
Next year I try them on my Harris 600 racebike in 10mm modification.
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I would use either copper core or silver core ( better) for racing. The Iridium core plugs produce a weaker spark than the other two, and will produce poorer combustion; okay for road use, but not for track.
 
I've tried Iridium plugs in my 'modern' Triumph (which is not known for weak ignition), big misfires at low rpm, turned back to normal plugs and all went back to normal. I have not made any more investigation but normal plugs are fine to me.
 
Paul LeClair said:
so anyone know what "silver" plug may be available and equivalent to NGK B8ES?
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Bosch W3CS; it's an old model, but it is still available.
Brisk LR14S, LR12SL for the SFC1000
Nology L4YS or L0S for the SFC1000

According to NGK : All motorcycle manufacturers now comply with current legislation which demands a standard of noise suppression on every vehicle. This is achieved usually by fitting NGK resistor covers though in many cases a combination of NGK resistor covers and NGK resistor spark plugs (R type) is necessary to satisfy the ministry tests. It is emphasized that despite the use of both resistor covers and spark plugs in such engines, due to the unique and superior construction of NGK branded products there is no loss of performance or shortening of service life.

A further bit of information from further internet sleuthing: Silver is the best conductor of any metal! It conducts 560% more electricity & 481% more heat than Platinum, and 276% more electricity & 177% more heat than Iridium.
 
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RGS1000RGS said:
Bosch W3CS; it's an old model, but it is still available.
Brisk LR14S, LR12SL for the SFC1000
Nology L4YS or L0S for the SFC1000

According to NGK : All motorcycle manufacturers now comply with current legislation which demands a standard of noise suppression on every vehicle. This is achieved usually by fitting NGK resistor covers though in many cases a combination of NGK resistor covers and NGK resistor spark plugs (R type) is necessary to satisfy the ministry tests. It is emphasized that despite the use of both resistor covers and spark plugs in such engines, due to the unique and superior construction of NGK branded products there is no loss of performance or shortening of service life.

A further bit of information from further internet sleuthing: Silver is the best conductor of any metal! It conducts 560% more electricity & 481% more heat than Platinum, and 276% more electricity & 177% more heat than Iridium.
Click to expand...
Maybe, but that's not the point. Using both resistor-type plugs and caps can seriously bugger up some aftermarket ignition systems. Seems nobody wants to RTFM anymore. Maybe the modern vehicle electrical systems that seem to produce more current than the power station down the road can cope with resistors in both components. Ask NGK what they're doing for our old bangers, which do not belong to the category "comply to current legislation".

The precious metals are not about conduction, it's mostly about wear. Healthy ignition systems of any type should work quite satisfactorily with run-of-the-mill copper core plugs, they generally generate more than enough oomph for a nice fat spark at the plug. Tired, old, magneto systems with points could well benefit from the superior conductivity of silver core plugs. Iridium plugs generally have a 100000km change interval in modern engines, something not even silver or gold-palladium plugs could achieve, mine all reached the end of their useful life around the 40000km mark.

Champion N2G and N3G gold-palladium plugs are still available here and there.

Although NGK B8ES and Champion N3C pop up next to another on comparison charts world-wide, they are not the same. Much the same with NGK 9 and N2. Close... but no cigar. The NGK 8s generally require rejetting from factory specs because they run a fair bit hotter, which is then falsley blamed on "modern fuels". With the 9s, it's the other way round, they are considerably colder than the Champs. Imho, a stock Laverda will run happily on modern fuels with factory spec jetting and correct plugs, which don't even need to be Champions!

Never seen anything about NGK products that would make them "unique and superior". Only thing going for them is that there's a rack of them in every second corner-shop...

piet
 
Not used iridium plugs in any Laverda motor i have worked on or re-built, cannot comment.

Users here have and report varying outcomes, noted. NGK were notable for stating in the plug charts that the outer two plugs on series 1 and series 2 180 motors had reduced plug gaps to compensate for the series plug firing, credit to the folk at NGK responsible.

Notable aspect of Breganze motors, let you know when something is not working, broad variances of installed parts, not of the factory era. Whatever the discussion on what is going out of production, so are we, our days are not forever ( happy thought..mmmm ). Seems there is a good remaining stock of BxES plugs around the globe, buy up big while you can, not dissimilar to the mountain of "spare" Laverda parts here.. bought while i could, plugs are exactly the same. Not sure endless discussion is a replacement for "buy up big"... factor to consider in looking to what you ride and for how long. HTH j.
 
All I can say Piet is that machines that ran fine a few years back now need leaning out and all that on the same plugs.
Apart from wear and tear, more so on some bikes than others, the only other variable is fuel.
Paul
 
iis_iis said:
Users here have and report varying outcomes, noted. NGK were notable for stating in the plug charts that the outer two plugs on series 1 and series 2 180 motors had reduced plug gaps to compensate for the series plug firing, credit to the folk at NGK responsible.
Click to expand...
Well I’ve never heard of this one,why didn’t anybody tell me!…..🧐😁
 
Should the modern ( 1995 onwards ) era replacement ignition be properly designed and manufactured, there is no need to alter the plug gap on the outer cylinders of the 180 motors, i do not alter the gap, plenty of energy to bridge a doubled gap, especially for cold crank starts. HTH j.
 
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