Denso spark plug probs

[chrisNI]

It's probably the world we live in. I have a feeling that the previous NGK problems were down to the plugs no longer being made in Japan, probably Denso have gone down that route too. Globalisation eh? Same as Yuasa batteries - up until recently a byword for bulletproof but I have a feeling recent ones are not as strong as they once were and have my suspicions about these as well. No proof for any of this, but usually if stuff is farmed out to cheaper sources of manufacture it suffers and from the number of posts there have been about this with Denso looks like that's where we're headed.

All I know is that about year 2000 I started find NGKs to be shite whereas Densos at the same time were excellent and solved a lot of problems, but I haven't bought any in a few years as I haven't needed to. Maybe, especially with the downturn in the Japanese car industry, and the car industry globally, they've recently decided to cut costs by moving production elsewhere while in the meantime NGKs offshore plants have got the hang of making plugs.

This seems not just to be a discussion limited to NGK and Denso - check out this forum post on a classic car site about Autolite plugs for old cars and and Autolite spokesman's reply.

http://www.jalopyjournal.com/forum/showthread.php?t=358823&page=5

So - if your bike's hard to start chances are it will eat it's plugs whatever they are. Making it virtually impossible to start. Keep plenty of plugs in stock at least they're cheap if you buy boxes of 12 from sparkplugs.co.uk. Having said that if they weren't made so cheap they might last longer.

[toycollector10]

I spent $120 NZD on those damn iridium plugs. The gap is so small on them that if you are running a bit rich, and only a little bit rich, the effers foul and stop sparking when you are starting from cold and have to be on the choke.

Even when I was warmed up and running I felt they weren't as good as the NGK's. No bottom end torque, sluggish acceleration etc.

They failed me at the worst time. I put my NGK's back in and now I'm back in business, baby!

Having said that, iridium plugs, if they are working for you, will last for 100,000 kilometers. I run them in my rotten old Mitsubishi Galant and they are great for that purpose.

[chrisNI]

I just looked at the last box of Densos I bought which have been 100% it says Made In Japan on the box and Denso Japan on the plug body. What do anybody else's say to see if this theory flies?

I bought a couple of Yuasas for other bikes a few weeks ago to see if they're better han a couple of budget batteries in them which have gone tits up fairly quickly, I'm hoping they will be - it doesn't say on them anywhere where they are made though.

[mick znone]

bought two sets a 3 months back, made in japan on the box. the web site is still in japan.

[mick znone]

Cornish battery company told me yuasa batteries are now made in Wales, don't know if that was sales gumph or not.

[mick znone]

bought two sets a 3 months back, made in japan on the box. the web site is still in japan.

just looked at the website, its japan for sure, unless Ive suddenly become very dislecsick

[Al]

I sent a link to this thread to Denso and got this reply today.
I have cut and pasted the reply exactly as i received it so will leave you to pick the bones out of it.

Dear Sir.
We have cpoied and read all contents thak KAWASAKI users' spark plug opinion.
Some says DENSO is better. Some says NGK is better. We agree this kind of opnion varies
depend on waht they feel
spark plugs. Rob's case, his W24ES-U was fouled but his old NGK worked fine.
New spark plug may be fouled during repairing such as highrev without any load, piston
wshing with gasoline or any liquid.
As Rob did not mention it, it is hard or us to decide this failure happened one reason.
We sometimes send another set of W24ES-U in this case for customer satisfaction.

WEBMASTER@notes.denso.co.jp


AL

[mikey]

I get the impression densos are heading down the same path as ngks, as just recentley had a couple densos go down and stuck some realy old ngks back in and it ran ok, had a quote for some iridium plugs at about £40.00 would it be worth laying out this kind of money?

[Skunkwurcx]

I put a set of Densos in the Z a month or so ago. Since then it has run on three more than a few times and it has always been cyl #1 causing the grief. I put an old NGK in that cylinder and have had no troubles since, at least not with the spark plugs. It was always #4 that gave me grief when the NGK's were in.

[floydsz1]

Hi Skunk,
out off intrest try what i said before, when it wont run on a particular cylinder try pulling the cap of gently and just rest it on the plug , do this while the engine is running and see if it fires up. dont be afraid off getting an electric shock

[zed1015]

Never tried Denso's. Always used NGK's in all my bikes and never had a problem.

[Taffus]

Never tried Denso's. Always used NGK's in all my bikes and never had a problem.

time for an oil debate?

[Taffus]

using iridiums in the 1100 good plugs
ngk's in the 650 seem to work ok..... so buggered if Iknow whats best

[Steve Cooke]

NGK or Denso there both good plugs when they're working and they're both shit when there not, hope that helps.

[Taffus]

NGK or Denso there both good plugs when they're working and they're both shit when there not, hope that helps.

Hmmmm working plugs......sounds good