Hey everyone! Quick question: I replaced my spark plugs recently with new Iridium ones. It's the correct model, but I decided to go new and fancy for the metal rather than standard copper. But lately I've been doing some reading and found out that different metals have different burn temperatures and this can impact the bike.
So, can it really make a big difference? What plugs do you run? Should I go back to copper?
if it works, use it. :)
Next time you need plugs, go back to copper. Cheaper and work just as well.
The higher $$$ plugs clean themselves better and last longer, like 100K miles.
You replace them in 3-4K then stay cheaper ones.
Cool.
Buddha.
While iridium plugs are measurably better (stronger, hotter spark, better longevity, etc), it probably isn't really worth it on a bike like the GS. It's not going to gain you any horsepower, and if your bike is running correctly, the longevity difference becomes negligible. Different story if you were talking about a late model fuel-injected bike, but on a carburetted bike using 80's tech it just amounts to farkle.
Quote from: mr72 on May 18, 2018, 10:22:54 AM
if it works, use it. :)
Next time you need plugs, go back to copper. Cheaper and work just as well.
Not true, Iridium plugs will fire with less voltage than conventional plugs and one set will outlast the bike, add the value of yer time replacing the cheaper plugs?
Do it once, do it right....never look back
I agree, iridium plugs remain reliable and last far longer than traditional plugs. The question has to be however are they justifiable in a dinosaur like the GS5 given the increased costs and the fact the GS5 was designed to run with, and does quite happily on the old school ones.
Iridium plugs used to have a problem with the insulator snapping and falling over the gap a few years ago, but this seems to have been fixed. A fine wire will require less voltage to fire and fire more consistantly. It is also less likely to track if dirty. Iridium and my favourite gold/palladium plugs tend to last a huge amount longer as well. For a bike that uses a very old spark plug like this one you can possibly still get gold/palladium plugs.
They will NOT give you more HP, except when conventional plugs are at a stage where they are starting to iffy. At that stage they will give you more consistant spark and have more HP, but only by keeping the HP they should have
It's just a myth that they perform better, :bs: mostly put about by outfits who want your money!
They last longer, that's why they make 'em. If you need 50,000 ks out of your plugs, go for it.
buy the cheap ones, the bike's just gonna spit oil on them anyway. :laugh:
Plugs are a wear item. Regular Autolite, or NGK (whichever is on sale) work fine and are inexpensive.
Well thanks for he info everyone! My concern was more so with their burn heat and whether they'd be igniting enough to properly burn all the fuel. Copper plugs burn hotter and the bike is tuned for that - but I don't know if it's REALLY that big of a difference.
But hey, if you guys run iridium and don't see any issues, then it's probably fine!
Hi AstroP,
I don't think that copper plugs "burn hotter".
Plugs supply the spark only. They have heat ratings which indicate how much heat they can conduct away from the combustion chamber, a hot plug conducts less heat and is used in a case where an engine might be less of a performance engine and you need to keep the plug clean by burning off the gunk, a cooler plug conducts more heat and ensures a plug does not get too hot and cause preignition in highly tuned engines while still burning off the gunk.
Copper, iridium, etc all come in different temperature grades, so you can choose the same grade for the same application.
I've tried the fancier plugs and also found that they are not worth it on a bike that one tinkers on. Fine for set and forget situations. Remember, you drop a plug on the ground once and you should toss it. I found I had ot put in new ones long before the "due" date.
My 2p's worth:
Accidentally bought DPR9EA-9 instead of recommended DPR8EA-9 from fleabay (cheaper for box of 4). The 9 version runs slightly hotter and made a dramatic difference to cold starting over the winter here in UK - much easier & very rarely needed choke at all to start even at -5°.
This is at odds with the Haynes manual but hey, can only speak from my experience, case of serendipitous mistake. Have yet to see how they perform during prolonged hot weather - but that's a little unlikely in UK.
:cool:
Last year I replaced my plugs with Iridium after reading the wiki link about plugs.
http://wiki.gstwins.com/index.php?n=Upgrades.SparkPlugs
I too have the plugs with the 9 in the part number. I remember reading something in the Owner's Manual about the 3 different kinds of plugs available...
"DPR7EA-9 If the standard plug is apt to get wet, replace with this plug.
DPR8EA-9 Standard
DPR9EA-9 If the standard plug is apt to overheat, replace with this plug."
...and also when I pulled out the old ones that my bike came with from the PO, they were the 9 ones too.
Quote from: gruntle on May 22, 2018, 04:15:19 AM
The 9 version runs slightly hotter
Hi Gruntle, in fact, the "9' is cooler than an "8" and will conduct more heat away from the motor. Interesting that it should make a difference to starting as this effect is only evident when the engine is hot.
Did you have many miles on the old plugs?
Reality is at odds with all the Haynes manuals I've ever read...
<quote>
Step 1: remove the gubbins
Step 2: before you do step 1, do this other, vaguely detailed, vital step or you've broken your machine and now its scrap.
</quote>