spark plugs

[valkyalky]

What are the best plugs for performance on my 99 tourer. Stock with a cobra 6x6 exhaust. 37000 miles. Thanks

[doubletee]

My motto? If it's running well with what's currently in it, why change? I'd put the same brand/type back in it.

[Patrick]

You won't change performance by changing plugs, unless the plugs you have in it now are defective.. I'd recommend using what is called for..

[John U.]

The above advise is certainly good. However, if you want to play with something different, try Iridium plugs. They require less voltage to fire, allowing you to increase the gap a little. At the standard gap they are easier on the ignition system and will fire without fail under heavy load: http://www.sparkplugs.com/results_appOther.asp?otherMotiveID=225263&mfid=1
They are standard equipment on newer Honda cars.

[Farther]

I just today installed a set of NGK Iridium IX (DPR7EIX-9).  It is too early to tell but I got about a 2 mile increase in fuel this last tank and the Valk runs slightly smoother.  It all could be just from new plugs.  I also had to replace a 6 week old battery, but that's another story.

[22Dasher]

What did you set the gap at for your plugs? I'm looking at. Set to put in my bike and just curious at what would be the optimum gap setting.

James

[Mikey]

I can vouch for the Iridium plugs. I have put them in my snowmobile for the last 3 years, and the first year I put them in, I was able to pull away from a buddy's sled that had always beat me in the past (I'd estimate a 3-5 hp gain). However, that's a two-stroke motor, but I would assume the plugs won't hurt anything in the Valk. 

[Duey]

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[John U.]

What did you set the gap at for your plugs? I'm looking at. Set to put in my bike and just curious at what would be the optimum gap setting.

James

The manual calls for .031 to .035 gap. Iridium plugs will fire on less voltage so you can use a slightly wider gap but I wouldn't go farther than .038. Misfire under load could result. In addition you would be putting an extra burden on your ignition system. I briefly tried a .040 gap (Iridium plugs)and couldn't tell any difference in power or economy. I didn't feel any misfire either, and I didn't conduct a controlled comparison so unless someone else has, the optimum gap is still an open question.
In theory a larger gap will provide a larger spark and better ignition, it the coils are up to the task. To a point that is. A larger gap can also result in a slightly retarded spark. If you are running extra advance that may not matter.
Let us know your results if you decide to experiment.
 

[98valk]

What are the best plugs for performance on my 99 tourer. Stock with a cobra 6x6 exhaust. 37000 miles. Thanks

any stock plug, put the gap at .030, cut back the side electrode so that only half of the center electrode is exposed. round the edges.
I like using the auto lite 4164 which has a necked down center electrode and then mod the side electrode.

http://www.autolite.com/pdf/SparkPlugTypes.pdf   see #11

http://sparkplugs.com/more_info.asp?AAIA=&pid=8304

I don't like the stock plug wires, they are solid core with a big resistor in the cap. consider using moroso blue max spiral core wires, which I use or www.magnecor.com, great info where one will see the truth about spark plug wires.
any specilaty plug, platimun,  Iridium, etc., only work because other parts of the ignition system are weak. This is in Dr jacobs book.  those exotic metals have very high resistance, hence why the center electrode has to be so small.
hotter coils, better wires are the answer and modified plugs, which I do for all my vehicles. I was using a set of coils from a blackbird, quicker accel, but they would burn out the dyna ignition, so back to stock now. They wouldn't hurt the stock ICMs.  Also measure the ohm resistance btwn plug brands, they are all different.  http://www.musclemustangfastfords.com/tech/0207mmff_tech/index.html    by David Vizard tells why the plug mod works.

[John U.]

What are the best plugs for performance on my 99 tourer. Stock with a cobra 6x6 exhaust. 37000 miles. Thanks

any stock plug, put the gap at .030, cut back the side electrode so that only half of the center electrode is exposed. round the edges.
I like using the auto lite 4164 which has a necked down center electrode and then mod the side electrode.

http://www.autolite.com/pdf/SparkPlugTypes.pdf   see #11

http://sparkplugs.com/more_info.asp?AAIA=&pid=8304

I don't like the stock plug wires, they are solid core with a big resistor in the cap. consider using moroso blue max spiral core wires, which I use or www.magnecor.com, great info where one will see the truth about spark plug wires.
any specilaty plug, platimun,  Iridium, etc., only work because other parts of the ignition system are weak. This is in Dr jacobs book.  those exotic metals have very high resistance, hence why the center electrode has to be so small.
hotter coils, better wires are the answer and modified plugs, which I do for all my vehicles. I was using a set of coils from a blackbird, quicker accel, but they would burn out the dyna ignition, so back to stock now. They wouldn't hurt the stock ICMs.  Also measure the ohm resistance btwn plug brands, they are all different.  http://www.musclemustangfastfords.com/tech/0207mmff_tech/index.html    by David Vizard tells why the plug mod works.

How tough is it to attach the Moroso or Magnacor wires to the OEM boots? Did you use new connectors? I've considered replacing the wires but don't want to screw it up.
TIA

[98valk]

What are the best plugs for performance on my 99 tourer. Stock with a cobra 6x6 exhaust. 37000 miles. Thanks

any stock plug, put the gap at .030, cut back the side electrode so that only half of the center electrode is exposed. round the edges.
I like using the auto lite 4164 which has a necked down center electrode and then mod the side electrode.

http://www.autolite.com/pdf/SparkPlugTypes.pdf   see #11

http://sparkplugs.com/more_info.asp?AAIA=&pid=8304

I don't like the stock plug wires, they are solid core with a big resistor in the cap. consider using moroso blue max spiral core wires, which I use or www.magnecor.com, great info where one will see the truth about spark plug wires.
any specilaty plug, platimun,  Iridium, etc., only work because other parts of the ignition system are weak. This is in Dr jacobs book.  those exotic metals have very high resistance, hence why the center electrode has to be so small.
hotter coils, better wires are the answer and modified plugs, which I do for all my vehicles. I was using a set of coils from a blackbird, quicker accel, but they would burn out the dyna ignition, so back to stock now. They wouldn't hurt the stock ICMs.  Also measure the ohm resistance btwn plug brands, they are all different.  http://www.musclemustangfastfords.com/tech/0207mmff_tech/index.html    by David Vizard tells why the plug mod works.

How tough is it to attach the Moroso or Magnacor wires to the OEM boots? Did you use new connectors? I've considered replacing the wires but don't want to screw it up.
TIA

the autolite plugs come with screw on caps (tighten them good and use blue lock tight, they will vibrate loose over time, even on a auto or truck) so they can be used with the stock wires or aftermarket wires. no reason to use the oem boots, u just plug the new cables on. I think napa also sells the caps by themselves to use on the stock plugs.  I plastic dipped the moroso boots to match the cable color.