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NGK iridium plugs run 1 tank of gas so far. Noticeably smoother off throttle and thru the rev range. DP air lid, K&N filter, Fatduc, G2 tube, stock pipes. DCPR9EIX $10.00, gapped @ 30 thousandths. One heat range colder than stock, no 10's in the catalog. NGK goes colder on higher #'s, opposite of all others ex. Champion, Autolite. Article in May '09 Thunderpress "Motorhead Memo" on iridium plugs.
 

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I just bought two online. Thanks for the motivation, as I have been pondering these for a while.
 

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Over at the Multistrada forum, a lot of us switched to iridium plugs... it made a HUGE difference in the smoothness of my 620. Instead of chattering down below 4,000 rpm, I could putt-putt in town down closer to 3,000 with the iridium plugs. Better gas mileage, too.

An iridium plug even made a difference in my wife's 50cc 2-stroke scooter! Way smoother and a little peppier.

It's on my list of upgrades for the Hyper once it's had the 600 mile service.

And, yes - you'll need FOUR plugs for the Hyper!! :)
 

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0.030-in is too small

Regarding the use of platinum and iridium spark plugs in a Ducati:

Both NGK and Denso pre-gap their Ducati application specialty plugs to 0.035 in. This should be considered a MINIMUM gap for this kind of plug.

When it comes to spark plug gaps, bigger IS better. The larger the spark kernel that is generated by a spark jumping the electrode gap, the more likely and complete the fuel burn will be, and the smoother the engine will run. That is, the larger the spark gap that’s exposed to the air/fuel mixture, the easier it is to initiate combustion. This translates directly into improved throttle response.

The transition between throttle positions involves a wide range of fuel/air mixtures and the ability to fire these less-than-ideal mixtures with a minumum of misfires is what throttle response is all about.

Platinum or iridium plugs will give you worse performance than a conventional plug unless you use a larger gap than is recommended for the steel electrode plug equivalent. One by-product (and benefit) to having platinum or iridium as an electrode material is that the harder material erodes more slowly and consequently allows you to reduce the size of the center electrode and still have a long-lifetime plug. Re-gapping is infrequent or eliminated. In fact, the initial reason this type of plug was developed was an attempt to meet the 100,000-mile durability/maintenance requirement mandated by the US EPA for exhaust emissions, not because they offered any improved performance over conventional electrodes.

A smaller electrode, however, will arc at a lower voltage. This is good because the lower arc-over voltage is not as demanding on your less-than-new ignition coils and wires so the firing is more reliable. But this is also bad because a lower arc-over voltage presents a weaker spark kernel (lower arc current and duration) that is less likely to light off the air/fuel mixture.
 

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It is good to see you back Shazaam!!!!

Regarding the use of platinum and iridium spark plugs in a Ducati:

Both NGK and Denso pre-gap their Ducati application specialty plugs to 0.035 in. This should be considered a MINIMUM gap for this kind of plug.

When it comes to spark plug gaps, bigger IS better. The larger the spark kernel that is generated by a spark jumping the electrode gap, the more likely and complete the fuel burn will be, and the smoother the engine will run. That is, the larger the spark gap that’s exposed to the air/fuel mixture, the easier it is to initiate combustion. This translates directly into improved throttle response.

The transition between throttle positions involves a wide range of fuel/air mixtures and the ability to fire these less-than-ideal mixtures with a minumum of misfires is what throttle response is all about.

Platinum or iridium plugs will give you worse performance than a conventional plug unless you use a larger gap than is recommended for the steel electrode plug equivalent. One by-product (and benefit) to having platinum or iridium as an electrode material is that the harder material erodes more slowly and consequently allows you to reduce the size of the center electrode and still have a long-lifetime plug. Re-gapping is infrequent or eliminated. In fact, the initial reason this type of plug was developed was an attempt to meet the 100,000-mile durability/maintenance requirement mandated by the US EPA for exhaust emissions, not because they offered any improved performance over conventional electrodes.

A smaller electrode, however, will arc at a lower voltage. This is good because the lower arc-over voltage is not as demanding on your less-than-new ignition coils and wires so the firing is more reliable. But this is also bad because a lower arc-over voltage presents a weaker spark kernel (lower arc current and duration) that is less likely to light off the air/fuel mixture.
 

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I have run these in all my bikes in the last several years. I have been meaning to drop a couple in the Hyper, but haven't gotten it done. I always gap to the upper end of the recommendation, but not over.

I can't say I have seen a noticeable performance gain, but they have been reliable. Plus it is fun to say iridium.

Out!
 

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NGK iridium plugs run 1 tank of gas so far. Noticeably smoother off throttle and thru the rev range. DP air lid, K&N filter, Fatduc, G2 tube, stock pipes. DCPR9EIX $10.00, gapped @ 30 thousandths. One heat range colder than stock, no 10's in the catalog. NGK goes colder on higher #'s, opposite of all others ex. Champion, Autolite. Article in May '09 Thunderpress "Motorhead Memo" on iridium plugs.
Michael, I hate to tell you this but, go back to the #8 heat range (hotter), I just finished my motor mods, I went big bore, HC pistons, cams, bigger valves, porting, ceramic coated pistons tops & combustion chambers, with the Febur oil cooler, and I also put in the NGK DCPR9EIX gapped to 27 thou, to make sure that my bike would not run too hot, the bike ran great, but it ran cool, cooler than the other Hypers that I compared my bike to.

After I had a conversation with the guy who did my engine coatings, he said that for best performance that I should be running 1 to 2 range hotter than stock! & that the coatings would protect my engine, so when I was doing my dyno runs I ran the #9 (cooler) plugs and than switched to the hotter DCPR8EIX (stock heat range) also gapped to 27 thou, and guess what? I picked up 1HP on the dyno with just the plugs. My bike is now making a little over 102HP, but I still need to do some more testing/tweaking. The bike runs great! I gapped the plugs to the Ducati manual specs, 0.6 to 0.7mm (27 thou) What I just read from Shazzam's post, I did not know about, or I would have tried the bigger gap also, to see what it does.
But what I DID find out is that the bike does like the #8 heat range better than the #9 heat range, now you know Alex
 

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CDONA, Shazaam and "The Animal" thanks for the informative posts.Cassos told me he was running these plugs on the advise of Dukepilot, and suddenly I understood why I couldn't keep up with him!;) I will be ordering soon! But seriously, amazing how much difference a plug can make.
 

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Here are some tips from Trinity Racing on reading plugs for A/F ratio (jetting as it is referred to below), heat range, and detonation/pre-ignition.

Q: How do I read my spark plug?

A: To properly read a plug, you will need a 10x illuminated magnifying glass.

1. Set your heat range from the ground strap (this is the piece closest to the piston).

2. Do all plug readings for jetting from the base ring (the base ring is what the ground strap is welded to at the end of the threads).

3. You determine detonation and timing issues form the porcelain (the porcelain shows pre-ignition/detonation, it will not accurately determine jetting/air fuel ratios.

DO NOT BASE JETTING DECISIONS ON PORECLAIN COLOR.

1. How to determine plug heat range:
The ground strap is your window to getting this right. If the color of the ground strap changes near where it is welded to the base ring, then it means that the plug heat range is too hot (heat transfer to the base ring is too slow, causing the deposits to be burned off the strap completely). The strap at this point could start working like a glow plug, probably resulting in pre-ignition and/or detonation. The properly set heat range is when the color is at the halfway point on the strap.

2. Reading the base ring to determine jetting:
The base ring color is very close to the color of the piston crown and is used to determine jetting. You're looking for the soot color to be a nice light to medium brown. If the color doesn't go all the way around the base ring (at least one full thread turn on the plug) or the color is white-ish, it is too lean. If the color goes all the way around, but there is a spotting of heavy dry soot on the top of the color, you are too rich (two-stroke jetting will be a little wetter looking and darker than on a four-stroke).
3. Read the porcelain to determine detonation/pre-ignition:

The first signs of detonation/pre-ignition will be seen on the porcelain down in the plug. It shows up as tiny black or shiny specks of aluminum. Also look very closely around the center electrode where the porcelain intersects. This will appear to be melting between the insulator and the electrode.
Detonation is caused by the air/fuel mixture exploding rather than burning. This gives off a sound (a knock). This sound is the result of a shockwave. This wave disrupts the boundary layer of cooler gasses that cover the internal parts of the combustion chamber. This causes a very rapid rise in pressure and temperature. The results are holes in the top or sides of the piston, blown head gaskets, or broken rods. This can also shock the rings from their seals, causing oil to form as little spots on the porcelain.


Out!
 

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Discussion Starter #15
The gap was a guess based on the article, it hit on the benefits of the larger gap of this plug, I had no hard info. I went colder to help the engine remove heat for the emissions tuning in my motor. Performance tuning would be different due to the amount of fuel doing the work and keeping the plug clean enough to fire. Just finding a plug number here in Cottonwood is stretching my resources. As we used to say in the hippie days, "spark it up":cool:
 

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My recollection is that the NGK Iridium plugs come "pre-gapped", and the instructions say NOT to change the gap. Also, the metal is very brittle and can snap when bending it...
 

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For anyone looking...Autozone stocks the DCPR8E and they can get the DCPR8EIX from the warehouse by 2 pm if you order before noon. I just picked up a set of DCPR8EIX from the local Sea-Doo dealer. It's a common plug in Bombardier watercraft.
 

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I am glad that I got the DCPR8EIX plugs as my bike runs cold enough as it is. Less then $35 for a possible 1 hp gain is pretty cheap coming in just after the opened up airbox lid for $:HP ratio on this bike.

I already run a slightly wider plug gap with the standard spark plugs on Shazaam's advice a year or so ago and my bike has always ran great.
 
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