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[Yorkie]

Hi Scalyback, AC45XL is the equiv.

Hope this helps

[Scalyback]

That helps, thanks!


there only seems to be one heat setting's difference between Tornado, my 500 military bullet and Kevin, the Meteor Minor.



So If I want to use non resistor plugs, I can just use resistor caps? Or does nobody listen to long wave anymore?

[ric]

You only need 5KΩ of resistance to protect your electronics from stray RFI.

If you don't have any electronics on your bike in need of such protection then go for it and play havoc with those longer waves


I often heard it said (when they were current and popular) that if you ran without resistor plugs and plug caps on an the Yamaha RD350 Powervalve the stray RFI would cause the valves to fluctuate causing erratic high speed performance; although I never once suffered with it on mine.

[ric]

The majority of good plug caps actually have 5KΩ worth of resistance and spark plugs are meant to have the same amount although NGK are the only company as far as I'm aware to guarantee that amount and then it's only in their more exotic plugs like the IX range.
Other NGK 'R' plugs can vary from 3.5KΩ to 5KΩ which is probably why they also supply a 1KΩ suppressed plug cap. Pick and mix at its best

[Scalyback]

Having now had a hunt around, would Tornado be ok with the following older plugs?



NGK B8ES Recommended


Lodge 3HLN

KLG FE100

AC 42XL

Champion NA10

[nigelphoto]

Now here's an interesting thing, Sir Oliver Lodge, born in the Potteries was the inventor of the spark plug - just thought you'd all like to know. However, our esteemed hosts suggest that the only correct plug for the EFI engine is the Bosch "Technical Notes -- EFI 500 There seems to be some confusion over the special spark plugs fitted as standard to EFI 500 engines. The standard plug is an Indian made 'Bosch' item (WR7DDC4) with two side electrodes and a unique heat range. There are websites that suggest equivalents as replacements for the standard item. Having made detailed enquires with the world's leading spark plug manufactures we have been told there are no equivalents currently available. Our own tests confirm this, with alternative plugs producing poor performance - or worse! We stock the standard plugs, part number 572025 price £5.34 (plus postage and VAT)." I'll go along with that - certainly much better than the NGK BPR6EIX which sooted up after just a few miles in my Classic 500.

[Vikinglynn]

For you history buffs: a black american, Edmond Bergeris credited with inventing the sparkplug in 1839, but without a patent. He was followed by Belgian Etienne Lenoir's contribution in 1860. N. Tesla, Richard Simms and Bosch patented their plugs in 1898, with Bosch's engineer Gottlob Honold, Wiki tells us, designing the first viable spark plug in 1902. Thereafter, improvements were made by Albert Champion, the above named Lodge brothers, and Kenneth Guiness, yep, the brewing family developed the KLG spark plug brand. Who said motorcycles and beer don't belong together?

[jefrs]

The NGK "IX" is the iridium plug which apparently doesn't fare too well in our motors.



Both the Bosch-India WQR8DC and the WR7DDC are Q for quick-heat, R for resistor, second D for Dual electrode (impossible to clean or set) both are shown as heat equivalent to a NGK "6", neither are mainline Bosch plugs, India only. However the NGK "5" is given as equivalent to the Bosch "8" heat range. Go figure.



Further digging revealed the BP6ES/BPR6ES is sold as a lawnmower plug and it looks it compared to the car-specific BPR5ES for the Vauxhall Nova and a few others. Probably a lower tolerance spec. Anyway the BPR5ES nose burns a better colour than the the BPR6ES which also misses occasionally, on my bike which is slightly tuned up a bit (NB). I think I've tested every plug available for this motor now, it's all nice and clean again and staying clean, the BPR5ES is doing good, NB again, in my motor.

The NGK R is resistor plug, no suppressor cap required, which is to say it has the correct resistance for itself, which a generic suppressor cap may not.