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1985 VN-700
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Discussion Starter #1
I put in new NGK plgs and seafoam. Boy it starts real easy now. Over night it turned over maybe 3 times and fired up with the choke. Now if it will only do on a cold morning. I think I had bad plugs, and I think it was pulling the battery down when starting. It hardly drops now, but the it starts right up in a turn or two. :smiley_th
 

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ok I know alot of you guys run the iridium plugs ........ why it is not a good conductor for electricity first is Silver you can get those from nology and the second best is copper. regular spark-plugs which last for 3-6k miles are some of yall that lazy you cant change 4 plugs for 5$ at that interval? dont waste your money on iridium.............. and platinum is hard on ignition coils so stay away from that crap to.


platinum and iridium plugs are crap the ONLY reason they made them was to live up to car warranty's of 50,000 miles and 100,000 miles THAT IS IT! they do not fire better don't waste your money on 13$ spark plugs thats crazy:wow:


I did run the silver plugs in my daytona 675 they ran good but it only had 1 electrode and the stock style is a dual electrode which i believe gives a more even burn in the cylinder, the way they are positioned so I went back to copper on the daytona aswell, you can play with heat ranges depending on your mods you may try a step or 2 colder if you have a full flow exhaust
 

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ok I know alot of you guys run the iridium plugs ........ why it is not a good conductor for electricity first is Silver you can get those from nology and the second best is copper. regular spark-plugs which last for 3-6k miles are some of yall that lazy you cant change 4 plugs for 5$ at that interval? dont waste your money on iridium.............. and platinum is hard on ignition coils so stay away from that crap to.


platinum and iridium plugs are crap the ONLY reason they made them was to live up to car warranty's of 50,000 miles and 100,000 miles THAT IS IT! they do not fire better don't waste your money on 13$ spark plugs thats crazy:wow:


I did run the silver plugs in my daytona 675 they ran good but it only had 1 electrode and the stock style is a dual electrode which i believe gives a more even burn in the cylinder, the way they are positioned so I went back to copper on the daytona aswell, you can play with heat ranges depending on your mods you may try a step or 2 colder if you have a full flow exhaust

Well qweesy I`m no expert on the subject, but your opinions seem to leave you swimming upstream against the mainstream experience here. Some of what you say may have merit, but all I see are opinions. Do you have any references or links you can post to back up your claims? I`m open minded to reading any factual evidence you can supply, but this is the first time I have heard that platinum or iridium tipped spark plug electrodes create more electrical resistance and are hard on ignition coils.:confused:

I have NGK Platinum plugs in my 1992, 3.8 L Olds Delta 88 with 40-50 K miles on them. They show no wear on the electrodes and it runs and pulls just as strong now as it did when they were new. Iridium is even harder than platinum, and logically more resistant to electrical spark erosion.
 

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iridium plugs use less "juice" from the electrical system, thus making it easier to start....they last forever.......also, the smaller tip means less of the energy produced is absorbed by the plug, therefore more of the energy developed is actually delivered in the spark.
 

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no iridium's require more juice than copper or silver because its not as good of a conductor of electricity, the other thing I see is alot of people just buy plugs and pop them in thinking they are pre-gapped.......wrong gap your plugs

(Nology)
Why not Iridium Spark Plugs? Iridium is a super dense material and therefore extremely resistant to wear. That's it! It is a terrible thermal conductor and a bad electrical conductor, so why would anyone use it to make a spark plug center electrode? Since car manufacturers have to guaranty that their engines stay in-tune for up to 100,000 miles, they can only achieve this with ultra dense Iridium or Platinum.


Silver is the best thermal (heat) conductor of all metals

- Allows for a wide spark plug heat range
- Excellent heat dissipation under max. power
- Excellent resistance to fouling under light load operation
Silver is the best electrical conductor of all metals

- Most free electrons
- Best power delivery
- Most powerfull spark


Best Materials for spark plugs by rank
1.Silver( Change every 4-6K) Not so Cheap Though at 8- 10$ a plug take out and view if good keep on going
2. Copper( change every 4-6K) CHEAP
3. Gold (haven't seen too many of these) but champion makes them and champion plugs are known foulers
the two below are used for the LONGEVITY FACTOR that's it! so don't buy into the hype!

4.Platinum (Hard on Ignition coils though) good for 50k miles
5.Iridium ( good for 100k Miles)




(NGK)
Heat range

The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.

The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.

An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.

The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.

Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
 

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You nailed it qweesy. I'm lazy and the iridiums are staying in there.
 

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That's some good theoretical info, however, you can't base real world performance on that info because of a few key elements...

For one thing, the whole spark path through the spark plug is not made of Iridium or Platinum. On most platinum plugs the center electrode is only coated in platinum, it's still copper under the coating, so you can't expect a high drop in conductivity.

Also, you're not taking into account the design of the plugs. The plugs would have to be made exactly the same, but using completely different metal (not a combination of copper and another metal) to find extreme differences.

The Iridium plugs have a very very fine tip, which is what is claimed to make the spark jump a lot easier than regular copper plugs. I can't truly back this up with any real testing, but this is the reason that they are supposed to use less voltage to make the spark jump through the gap. In any case, the fact that they have a different design means you can't compare them only with the metals' conductivity numbers.

Finally, here's some REAL WORLD measurements...

http://forums.modulardepot.com/showthread.php?t=62402

this guy took a bunch of used copper plugs, new copper plugs, used platinum plugs and new platinum plugs, and measured their resistance... if what your info says were true, there would be a HUGE difference in electrical resistance measurements. There isn't.

He also points out how, if the platinum's resistance was 10 times higher than the copper plugs, assuming 35 000 V from the coil, there would be a loss of about 120V... 120V from 35000V... not a big deal if you ask me, and this is IF the resistance was actually greater, but it's not.

With the Iridium tips you can argue that the tip itself is actually made of Iridium and not a copper core coated with Iridium... I still doubt it would make that much of a difference, however, there is still the matter of the design to be taken into account. You just can't compare only conductivity numbers with two different designs.

I don't have data to support the claim that the spark jump takes a lot less voltage to accomplish with a thinner tip, but I do believe it. Why? Because I know how my bike reacted to the Iridium plugs.

When I first got my bike it was too hard to start and the battery would drain trying to start it. I got an MF battery and it was still a bit hard to start but the battery could take it. Then I got a new set of copper spark plugs... now I had good battery and new cooper plugs... it would crank for 2-3 seconds and start right up. I considered this to be good starting. I changed the still new copper plugs (doubt they had even 100 miles on them) for Iridium plugs and tested the starting... it started as soon as I pressed the start button, not a second of cranking. This is real world experience right here, which is what really counts in this matter. I don't think there's anything that could have been done better to ensure a good comparison of spark plugs than what I did... both the copper plugs and iridium plugs were new, there was a new battery installed before any of the spark plug changes and nothing else was changed. It was even done on the same tank of fuel. So I say the design actually does what it claims to do :)
 

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I have cheapo plugs and it starts and runs everytime. lol!
 

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I have cheapo plugs and it starts and runs everytime. lol!
lol yea, mine started with the cheap plugs as well... it was just better with the Iridium ones :)

What about your bike's starting though, does it have to crank a little or does it start immediately after you press the button?

I considered mine to start well with the copper ones, but it did take a little cranking, not much, just like 2-3 seconds of cranking and it fired up. With the Iridium ones though it fired up immediately, no noticeable cranking.

Just trying to see if it's the same with other bikes or just mine.
 

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That's some good theoretical info, however, you can't base real world performance on that info because of a few key elements...
This is real world brother and the fact is whether you like it or not platinum's and iridium's are not better conductors than cheapy coppers. Period the end Ive seen many spark plug demos come in to NAPA and try to sell us their type of spark plug and the biggest and strongest spark comes from silver plugs 2nd is coppers, spark plug technology has not changed much since the 1940's so don't buy into the hype its a gimmick and they ONLY reason platinum's and iridium's plugs were introduced were for factory warranty claims saying no service to the the ignition system until 50k-100k miles, they don't make more power and they don't give better fuel economy or whatever you like to believe, whether you like it or not that's FACT!

Not trying to be an @$$hole just tryin to save you guys some money from experience and seeing demos of just about all types of spark plugs, resistor plugs and those new E3 plugs<<< these are really crap and they are like $20 a plug:wow:. But if you want to justify your purchase of 4 plugs for 50$ by seat in pants then by all means go ahead its your bike you do what you want but ill stick to my $5 for 4 plugs and ill use the other $45 for more Guinness at the bar:smiley_th
 

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I never argued that they were better conductors. Just that they don't make enough of a difference in conductivity. You're still saying the same thing and not even mentioning what I think is the biggest difference between the spark plugs, which is the thinner tip.

I might even be agreeing with you if I hadn't tested both spark plug types on my bike and seen a big difference in starting. However, I can't just dismiss what I saw on my own bike.

Also, you might save a few bucks on the copper ones initially, but I'll probably only need to buy this one set of Iridium plugs for the entire life of the motorcycle, so they'll end up being cheaper in the long run... and they're not that expensive anyway, I got them for like $8 each plug I think.
 

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I have to go with Ceal here... they last longer and give me a hotter spark on hot restarts...it was a good switch!
 

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1985 VN-700
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Discussion Starter #14
Mine had Champions in it that were probably in there a very long time, and bad for a very long time. I had no problems until last year. Had a bad battery, ran like a beast backfiring and farting the 12 miles home. I think I may have ruined them then. I know I never ran Chumpians in any Japanese bike I have ever owned. I tried Iridiums in my old Honda CR-250 Elsinore and it used to eat them like candy every time I rode. So for after wasting 5 bucks a plug per ride I went to the standard NGK. I bet the iridiums would work better in the 4 stroke vulcan, maybe next time.
 

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Sorry qweesy....but you are wrong on a few ponts here. I admire your conviction but as they say, a little knowledge can be a dangerous thing..;)

If all a spark plug had to do was just be made with the best electical conductor you could find....your arguement would have merit. But there is more to making a spark plug than just picking a good electrical conductor.

First off Ceal..yes it does take less voltage to jump a tiny wire.

Iridium is not as good as a conductor as silver. But it is hard and dense...(the 2nd most dense element on the planet) It also has a real high melting point, around 4400 F. And is does not rust or corrode.

Normal spark plugs have thick electrodes....that due to the metal used, over time they errode, the end rounds off and they produce a weaker spark compared to the iridium plug. Sparks like jumping from nice clean sharp edges...so when you put in a new set of regular plugs...the center electrode is nice and square. Over time however it rounds off, and the electrons find it harder to find a nice pointy departure spot.

Iridiums on the other hand do not errode as quickly..and because iridium is so hard and melts at such a high tempature...they can make the center electrode alot thinner. This provides those electrons a constant fine edge to leap from. So a set of plugs will still spark with the same verve they did when they were new for a much longer time. They provide a consistancy you can not get in regular spark plugs. And yes due to this they provide a hotter spark...over time.

A new set of normal plugs actually begin to deterioate from day one. If nothing is wrong with the fuel mix..they will just slowly wear out.

Iridium plugs do last a very long time...but that is not the selling point...that you never ever replace them ...but that because they do last...they simply provide a more consistant spark way past the life of a normal spark plug.

Anything can be used to conduct electricity...the key is finding something that does not burn itself up. I can run accross the carpet in my socks and provide a pretty good spark when I touch the door handle...My finger would make a lousy spark plug however because it would not last in the enviroment.

Silver is a great conductor...but it is soft, has a low melting point, and it corrodes, the oxide that can coat is actually acts as an insulator.

Yes it works fine for awhile..but slowly degrades...and usualy just slow enough you likely can't see the difference until it gets bad. So you replace them...no big deal. Agreed there, but why buy a 3 dollor plug you will have to replace a few times when you can buy a 7 dollar plug that you likely never will?

You can't hurt your coils with any spark plug unless it has shorted out somehow. Ignition coils put out 20-40 thousand volts... you can make a spark plug out of pretty much any conductive metal and you are going to get a spark.

There are gimicky plugs on the market that make alot of claims. As far as I know I have not seen any advertised hype on the iridium plugs....because they don't need it...they sell because they work, and everyone here who has switched to them can tell you they do.

So if you like changing plugs...and don't want to spend the money...no problem. I on the other hand would rather be riding than wrenching.


KM
 

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My bike just starts right up no cranking or anything even in this cold wisconsin weather.
 

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KM that was exactly the point I wanted to make but didn't have any data to back it up, other than how I think it works lol. You seem to have done a much better job at explaining it than I could have :D
 

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yeah well you lose power with iridium's so enjoy:smiley_th ill be back with a big ass post g2g right now
I suppose their power robbing characteristics is why all the new,high compression,close to 200 horsepower super bikes come from the factory with Iridiums ,You kind have backed yourself into corner on this one.I gotta go with the majority on this one,and maybe you should "man up" and consider everybody else may not be out of step on this one,Just coming back with a longer post doesn't do anything to help your case if you can't cite relevant materials to reference to.
 
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