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Denso spark plug probs

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AndyZ1R
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#31 PostAuthor: AndyZ1R » Tue Jun 09, 2009 6:42 pm

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


Nail on the head.........

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Al
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#32 PostAuthor: Al » Tue Jun 09, 2009 7:30 pm

Had a very very good listen to what someone who knows had to say about this today;

Neither NGK or Denso use porcelain in the tip insulator any longer.
Reason is because of the temperature and running conditions of lean burn modern engines etc.
Problems have been manifest in old style china tip insulators falling off and we all know where that leads.

The new material that they are using (XXXXXXX) what ever its called is very porous indeed un-like the old china were used to.

It has a couple of very interesting properties which relate to bikes with ignition systems like ours. Twin tower coils etc.

Firstly; they will not tolerate any amount of over fueling!
This causes absorbtion in the tip insulator and causes the spark to leak away to earth down the side of the insulator or through its material pores and away to earth rather than jump the gap!

They will not tolerate being used for any length of time and then being stood without use for any length of time. Hand in hand.
ie. laid up over winter with brand new plugs and expect them to work in the spring. Same reason; absorption of fuel oils moisture from atmosphere.

There is no longer any 'surface' to the tip insulator.
Once upon a time you could wire brush them clean even shot blast them at home with one of those K-TEL spark plug cleaners.
No more. Touch them with a brush (even brass) and their dead!

Secondly; and similarly; they will not tolerate any over oiling. Putting oil in the chamber to test for compression, leaking oil control rings very worn inlet valve stem seals etc.

£1.50 for a plug says it all really. Used to be that price 25 years ago so really they are a fraction of the cost they used to be.

Apparently irridium plugs are not any different and are made of the same materials on the nose insulator. They are showing up with the same amount of failures for the same reasons as the standard ones.
Although they have different condutor materials which off sets this to a degree! (Caveat)

The problem shows itself if you view your sparks.
I thought my problems were being caused by a weak ignition system and looking at the plugs i thought i would see a fat spark.
Instead with new leads and new plugs and boosted Dyna S all i get is a multitude of tiny sparks.
Looking at the tip insulators of the new plugs after 50 miles i can see a small pattern of black lines radiating out from the central electrode through the porous 'new' insulator material (one dead plug)
It still sparks but it will break down at various different heat ranges and under various different loads / compression pressures and fueling conditions.
Mine runs very rich at tickover......thats where it wont burn all its fuel so it dumps the sparks to earth through the insulator and this compounds the problem. Full circle as Piggy says.

The key thing is how it relates to our bikes and in particular our ignition systems;
On single tower sytems (coils) (twin cylinder bikes) the spark leaves the coil and returns to the circuit via the head as a form of earth. Fine

On Twin tower coils (four cylinders with two coils using a 'lost' spark arrangement) it leaves the coil travels through the head and travels back up the other spark plug back to the coil apparently.
This was a revelation to me.

The problem appears to be that in one direction the spark appears to want to jump the gap and when it gets to the other plug it may elect to travel preferentially up the inside of the porous nose insulator rather than 'SPARK'

I've been using my inductive pickup timing light to check the timing but also to determine fluctuating timing marks.
I thought i had a problem with a dodgy ignition because on number 1 i can get a stable reading, but on number 4 i get a fluctuating timing mark.

Not possible i thought but when you consider that in one plug the spark is travelling in one direction and in the same coils other plug it is effectively travelling in the other direction,...given that the inductive pickup on strobe is direction sensitive (has arrow on it) you begin to see why.

Answer here is to use the strobe pickup one way on one plug and the other way on the coils other plug!!!

Solutions; I dont have any apart from the above for inductive strobe pickups. Guess we've all made this problem for ourselves and i see no real way to over come it as yet.
My three year old NGK's work better than my brand new NGK's or brand new Denso's now i know why!!! They were made of different material on the nose insulator

Looking at the help section it is dogged by issues like mine where i thought that new plugs equals good sparks.
In my case it might have been true if i had removed all the assembly oil from the rebuilt top end and hadnt run it in by giving it the gun untill it ran nearly red heat from brand new. Its run in very nicely but has caused some big head aches with miss firing and fluffing and running on three etc.

Now who's going to be first to say "i dont have any of these problems" because i think that this is not going to cure itself any time soon.


Sorry for the rant.



AL

P.S I thought the most revealing thing he said was; this is not something which afflicts the young. Meaning we come from a generation where we would tinker with things to get them to work.
Kids just lob it in the bin and go get new stuff!!!! Very revealing i thought.

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#33 PostAuthor: mikey » Tue Jun 09, 2009 9:06 pm

Very informative Al thanks for posting that certainly explains a lot of things so in your view would it be worth the extra money for iridium plugs? just this morning fired my Z up and no 2 wasnt firing pulled the plug out gave it a wipe (wet plug) put it back in and all was well again, but probably same thing happen to another plug tomorrow.
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#34 PostAuthor: Ginger Bear » Tue Jun 09, 2009 9:10 pm

As Mikey says, very 'enlightening'...... Thanks Al.

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Al
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#35 PostAuthor: Al » Tue Jun 09, 2009 9:35 pm

would it be worth the extra money for iridium plugs?


In truth i dont know.

Ive heard people say "i think irridiums are good for 50,000 or 100,000 miles". That may be true but has anyone done 50,000 miles in the last two years on a Z with a 'modern' irridium plug.

£40 is a lot of money. All i can say is that it would appear that if what was told to me bears any resemblence to the truth then its a mistake to put expensive plugs in a bike which is not in perfect (100%) working order or when running in etc etc.
Precisely the time you or I might consider putting expensive plugs in a bike, is when we feel it might cure something.

Hope that makes sense.
Sort of counter-intuitive if you see what im getting at.

The only moral i got from this was 'hold onto your old plugs' cos you may find they come in handy.
Personally; based on what has been said i will modify my habits slightly and change plugs more often and not be so suspicious of my electrical system when something goes wrong with it. Oh Oh needs some more disposable plugs.
I wouldnt want to put £40 irridiums in only to find that they dont like rich running or lay up over winter or multiple short journeys with lots of choke.


AL

P.S. could be a load of old b*77*c%s but Fatty Z1R is about to come on and tell us how it really works. I think that will be fascinating.

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#36 PostAuthor: Steve R » Tue Jun 09, 2009 9:39 pm

Thanks for that.
Sounds like the only answer is to change the plugs often then, at £1.50 each I think I will just throw a new set in every 1000 miles or so.

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#37 PostAuthor: mikey » Tue Jun 09, 2009 9:42 pm

Thanks Al im very reluctant to splash out that kinda cash on plugs only to find its no better think its time to stop fiddling with carbs and ignitions and take it on the chin when a plug goes down and just clean it and pop it back in thats what im gonna do anyway. :??
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#38 PostAuthor: AndyZ1R » Tue Jun 09, 2009 10:14 pm

I was talking to the guy at Les Smith where i get all my top of the range Harry Moss products, and he says you are ''talking bollocks'' and that ''all you need mate is a good spark plug cleaner made by Ronco, that will sort you out.'' You can get one of their Fuzz-aways to tidy up your tank top and corduroys at the same time (or just borrow mine). I wonder if Ronco do a carb balancer?
There is some pretty good plug info on here by the way, worth a look: http://www.gsparkplug.com/
it may be worth giving them a call to see what they have to say? Apart from ''f**k off Al and stop wasting my time!''

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#39 PostAuthor: floydsz1 » Tue Jun 09, 2009 10:25 pm

mikey wrote:Very informative Al thanks for posting that certainly explains a lot of things so in your view would it be worth the extra money for iridium plugs? just this morning fired my Z up and no 2 wasnt firing pulled the plug out gave it a wipe (wet plug) put it back in and all was well again, but probably same thing happen to another plug tomorrow.


mikey,
if it happens again, before you remove the plug just pull the cap off the plug slightly and leave it just resting on the plug tip. see if it starts to fire, after about 30 secs push it back on. If your scared off getting a shock use some pliers, i just get hold off the plug cap if it happens on mine,

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#40 PostAuthor: Al » Tue Jun 09, 2009 10:38 pm

AndyZ1R
PostPosted: Tue Jun 09, 2009 10:14 pm Post subject:
I was talking to the guy at Les Smith where i get all my top of the range Harry Moss products, and he says you are ''talking bollocks'' and that ''all you need mate is a good spark plug cleaner made by Ronco, that will sort you out.'' You can get one of their Fuzz-aways to tidy up your tank top and corduroys at the same time (or just borrow mine). I wonder if Ronco do a carb balancer?
There is some pretty good plug info on here by the way, worth a look: http://www.gsparkplug.com/
it may be worth giving them a call to see what they have to say? Apart from ''fuck off Al and stop wasting my time!''


Fatty Z1R dont waste your paper round money on the Ronco carb balancer, iv'e got four lolly sticks just put them in the carb openings and twist the throttle.

Can you take the FUZZ AWAY to Avon Park on Saturday as i'd hate to be seen in the pits looking like the pits.

Did you dig out those blakeys for me too. The platforms are starting to wear down and look a bit like brothel creepers. Dont want anyone laughing at me, got a reputation to think of.

Chin Chin


AL

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#41 PostAuthor: Garn 1 » Wed Jun 10, 2009 12:09 am

Zorded, I've read a lot about plugs and your observations are definitely worth considering. About a year ago NGK plugs were being "put down" by all and sundry from this forum and Denso plug were the plug of the month.

I had noticed that many new plugs foul early and following the forum , changed to Denso's. However, after installing DynaS and Dyna Coils, I still noticed the failing of plugs. I think you may be onto the real reason for these failures "porous insulation tip"

I'm thinking the biggest mistake I may have made, after starting an engine after overhaul, is to give each cylinder a squirt of oil to ensure good compression on first start and thus saturating that spark-plug insulation.

I am also interested to note that you cannot use a bead-blaster to bring these plugs back to life.
RegardZ.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

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#42 PostAuthor: Steve S » Wed Jun 10, 2009 9:18 am

How long before a set of 'Classic NOS Porcelain insulator NGK spark plugs' come up on Flea-bay for megga bucks!! :D

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#43 PostAuthor: mick znone » Wed Jun 10, 2009 10:53 am

ive still got an old set of bh8's in my toolbox, came out of my lada :D
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#44 PostAuthor: kev edwards » Wed Jun 10, 2009 12:46 pm

That firing on three used to happen all the time on mine , new dyna and coils , denso's ngk's wiring all off checked cleaned , earth straps renewed , still the same , replaced carbs with standard ones and keyster kits , a whole lot better just got to replace needle jets now , got a set , winter job, also a freebreathing exhaust , sod the harris , starts on the button most times and goes like stink . ngks in it now i also cut a v groove in them like the denso's no probs with them now . Still it's all part of the fun of owning the King of bikes (more like bitch of bikes)

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#45 PostAuthor: mikey » Wed Jun 10, 2009 4:19 pm

floydsz1 wrote:
mikey wrote:Very informative Al thanks for posting that certainly explains a lot of things so in your view would it be worth the extra money for iridium plugs? just this morning fired my Z up and no 2 wasnt firing pulled the plug out gave it a wipe (wet plug) put it back in and all was well again, but probably same thing happen to another plug tomorrow.


mikey,
if it happens again, before you remove the plug just pull the cap off the plug slightly and leave it just resting on the plug tip. see if it starts to fire, after about 30 secs push it back on. If your scared off getting a shock use some pliers, i just get hold off the plug cap if it happens on mine,


Started it up today and all was well, but when it happens again ill try your tip thanks for that
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