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ET: Engine (Twin) Spark Plugs


Well Known and Active Website User
VOC Member
I think you've hit the nail on the head. Investment to start production. That assumes that you make that investment in equipment and materials. Yes plugs are simple in design and relatively cheap to purchase. That is why they are attractive to counterfeit. You go to a retail outlet and purchase a couple of plugs that are counterfeit and duds. You try and return them to the store, but as they are used electrical items mostly likely you aren't going to get them exchanged or your money refunded. So you go to another store, because you're angry at the first store for not refunding your money and buy a different brand of plugs because you've decided the first brand, rightly or wrongly, is rubbish. So you're out you're money. The retailer isn't out money, because he didn't give you a second set to try or refund your money. The retailer is only out a customer, for now. The distributor isn't out any money as the retailer didn't complain to him about the plugs and want a replacement set or a refund. The genuine manufacturer is out on their reputation and some money do to diminished sales, but not money for replacing the bad plugs. Even if the complaint had made it that far, the genuine manufacturer would eventually realize the plugs were counterfeit and most likely not replace or refund. The counterfeiter isn't out anything, he has your money.
When it becomes obvious that brand A is suspect and everyone is dubious of buying them, the counterfeiters move on to brand B. The cycle repeating itself till they run through all available brands, returning to brand A once that brand has restored its reputation. Because plugs are inexpensive we just replace them and don't complain to the manufacturers when retailers don't replace bad ones we have purchased. So the makers are not aware they have a counterfeit issue until sales drop off.
Let's be honest, most counterfeit products originate in countries that do not honor trademark, patent, and copyrights.
Eventually I'm sure the counterfeiters will realize the vast untapped market of counterfeiting New Old Stock, if they haven't already.

Nigel Spaxman

Well Known and Active Website User
VOC Member
Steven, thanks for sharing your troubles with NGK plugs in the forum. Seems fakes are a real factor with famous brands but I would not have believed that modest price items like spark plugs were attractive for fakers. When fabricating fake plugs there are quite some costs of investments to start production so one could produce working spares as well with no practical extra costs - or so I´d think. I have always had Bosch plugs since I was a boy as they have the nickel plated steel sections for nice shiny durable finish. With good luck Bosch seem unattractive for fakers as I never had defects as described. Basically a spark plug is no complicated item so should be reliable in operation. Some or most types have an inbuilt resistor for less radio emittance or limiting current from coils. I seem to remember that resistor plugs were not recommended for magneto ignition with poor mag types . A faulty resistor may be tested with a multimeter and in doubt the plug be scrapped. Anybody with a fake NGK for testing this ?? To be honest, I am now curious to get a fake for looking inside to learn what can be wrong with these. In most cases I only had fouled plugs in need for cleaning due to wrong grade choice.

View attachment 32901
I really like those cylinder head brackets, where can you get those?


Well Known and Active Website User
VOC Member
Hi Nigel,
not for sale anywhere, I made just 4 for our two B-Rapide specials. Could not succeed with deep finned alu sand casts at home. So I did very laborious milling jobs on my manual mill with a clever DRO - and a little help from a CAD program I found on the net for getting positions of intersections of all radii to feed the DRO . No CNC near, all radii milled in small steps, my old company with CNC is 3 km away and only after work for my actions accessible so I preferred my own machinery. Well, several weeks of milling and finishing with abrasives before bead blasting. My idea was to get a more rugged engine/UFM/head lug unit because the 12 nuts plus steel bracket original design looked very amateurish to me. Well, it´s cool to be different . . . .