Spark plugs ???

[Moorey]

Denso or NGK  has anyone any preference, if so why.?

[hairygit]

NGK every time for me, as long as they are genuine, a lot of "Fakes" out there now. Have used them since the early 80's when I bought a 750K2 that misfired constantly, in spite of being fitted with very expensive Champion A6G (gold tipped if I remember) After changing the points, condensors and coils/leads (bloody expensive!) and having the carbs apart several times, put a sey of NGK in, and it ran perfectly! Never suspected the plugs as they were brand new super duper Champions! Have used NGK on every vehicle since, and never had a plug fail.

[Nurse Julie]

NGK. The nice Sales Director at NGK sent me a huge bag of nipples FOC when they started supplying them without and I moaned.(Even to this day the  pic on the box still shows a nipple !!!)

[K2-K6]

There's an obvious double entendré going begging there Julie  must resist.

I've not often come across Denso plugs in use but when that's the case no problems encountered so no reason to say anything detrimental.

NGK have generally been more available over the years so most seem to use them. I can't even recall having one failed in normal service conditions, so 100% record in my experience.  As HG,  I run them in cars also,  again with zero issues. They'll easily run to 18,000mls in cars without any problems also. 

Seem exemplary in my view.

[Moorey]

It would seem after digging there is nothing to pick between the two. Even the Honda parts books lists both makes. Its down to personal preference then.

[SteveW]

Cheapest place to get them is Euro Car Parts, I got 4 NGK D7EA for £8.99 last week.

They are showing at the moment at £3.19 each, but with one of their discount codes will be way cheaper.

ECP part number is 408774560

[Laverda Dave]

Hairy, is it easy to spot a fake NGK from the real thing? A lot of stalls at auto jumbles sell NGK's and if fakes are out there it would be good to know how to spot them.

[hairygit]

The biggest giveaway I found was the brand name on the porcelain rubbed off with petrolly hands, knew that was not right. Sent it to NGK's U.K. address, and they confirmed it was one of many fakes coming from China. The core was steel (should be copper) and corrosion was actually causing it to split the porcelain, similar to how rusty reinforcing wires start cracking concrete!

[Laverda Dave]

Thanks Hairy, something to look out for in the jumbles.

[Spitfire]

Fake NGK's could explain a lot, when I got the old 750F1 back on the road I had a lot of problems with plugs fouling, in the olden days I always used NGK D8ES-L, but they don't make them any more so I got D8ES-L R, these did not work very well they fouled up very quickly, so I tried D8EA,s, these were better but still fouled. Then I read a thread on the other site in which Hondaman recommended the ND X-24ES-U and X-22ES-U, I now use these and they appear to be fine. The bikes standard apart from the DS silencer which has a couple of strategically placed holes drilled in the end cap.
Here's an article from the other site with Hondaman's explanation
http://forums.sohc4.net/index.php?topic=77832.msg869100#msg869100

Cheers

Dennis

[Rob62]

Another good way to spot the fakes is the price, especially if you buy them from unknown dealers on ebay. I would say the only way to guarantee genuine is to either buy from a recognised retailer online or buy from Halfords on the high street....... That reminds me, when i went to halfords to buy plugs for my 750 i noticed that they had in stock 1 of each type... so if you ride a single, Halfords may be ok, or alternatively you could make four separate visits with a delay inbetween to give them chance to restock, maybe a week..