Spark Plugs

[Deegz]

Just out of curiousity….. do you folks run non resistor plugs in your vintage bikes or would any type of spark plug be suitable. I’ve got a ‘78 GS1000 and run B8ES, would it be better to run iridium plugs (BR8EIX)?

Thank!

[zed1015]

No need for anything fancy.
Plain non resistor is fine especially if you have resistor leads or caps.
Never run more than one source of resistance if any..

[KiwiAlfa156]

As above, stock was resistors in the caps, none in the plugs. The exotic electrode plugs are more resistant to spark erosion, so wear slower and keep their sharp electrode edges longer. They don't add power, just deteriorate a slower rate. Makes sense for long service interval cars. Worth the extra money in a GS? Probably not.

[Nessism]

The resistor can be removed from the plug caps, and replaced with a chunk of solid core copper wire. That will allow running resistor spark plugs. Just an option...

[bwringer]

NGK discontinued B8ES (2411) plugs a few years back. They'll sell you the BR8ES (5422) resistor plugs as the replacement. These are externally identical and will screw in and work, but they are resistor plugs, not the correct non-resistor plugs.

The listings for the B8ES on scAmazon and fleaBay are for counterfeits; spark plugs are some of the most widely counterfeited items on the planet. Only order and install spark plugs from reputable automotive suppliers. Napa and a few other places list the NGK 2411 as available to order, but they will substitute the BR8ES/5422.


The Denso (ND) W24ES-U (4030) was also factory correct on the same GS models and seems to be available off and on. Right now they're on RockAuto for $1.42 each, so you might want to grab a few sets.


As Ed states, one resistor in the ignition at a time is enough. If you need to use resistor plugs, then use non-resistor wires and caps, or convert your caps.

[zed1015]

The listings for the B8ES on scAmazon and fleaBay are for counterfeits; spark plugs are some of the most widely counterfeited items on the planet. Only order and install spark plugs from reputable automotive suppliers. Napa and a few other places list the NGK 2411 as available to order, but they will substitute the BR8ES/5422.


.

Supplies of nos B8ES are plentiful and there are loads of genuine NGK B8ES on ebay but i'd steer clear of Amazon..
I buy them in boxes of 10.
Very easy to spot a fake and ebay always sides with the buyer if you happen to receive any and returns are free if the item is not as described so no big risk buying from there.
Lack of the part number on the hex flat and loose sealing washers are the main giveaway for NGK fakes but i've never had any yet.....

[Deegz]

Lots of good info!! I’ll look into the Denso’s just to have some spares. The B8ES plugs are a little hard to find but I have seen those 10 pack boxes around.

[Rob S.]

While we're on the topic, can someone give me a quick primer on resistor plugs? I was under the impression that they were conceived to give cleaner reception to car radios way back. Am I revealing my age?

[rphillips]

That's what I've always heard Rob. Wish somebody would verify for sure the reasoning.

[zed1015]

While we're on the topic, can someone give me a quick primer on resistor plugs? I was under the impression that they were conceived to give cleaner reception to car radios way back. Am I revealing my age?

Yes! They were initially developed to reduce interference ( static) with radios and tv's .
On newer vehicles they are also specified to prevent malfunctions with the onboard electronic ignition systems and ecu's etc which can affect running.
If the vehicle wasn't originally specified resistor plugs for it's own functional reliability it doesn't need really them.

[Gorminrider]

well, no, not the only reason. The resistance of the OEM spec plugs,caps, coils and BlackBox (or points if you have them instead) is calculated to "shape" the spark so it's just right at the right place in combustion. There's no doubt experts that change everything for better performance etc etc but randomly changing from the manual's specs as a personal theory isn't likely to help the bike IMO. even if it's not noticeably hurting it either.