Spark plug wire question

Hey guys, I have been considering changing plug wires (no problems with current ones....yet) mostly for looks, and possibly a little better spark. I have read most the articles on cutting the wires out of the coils (original coils) but dont want to try that until I try it on a used pair from bone yard. I was considering using the NGK adaptors that allow you to splice new wires into the originals that are molded into coils, has anyone else used these? good or bad results? Also was wanting to go to the car style (I beleave they are graphite cores) instead of the original style copper (metal strands) core. anyone know if this will cause any issues? And can I still use the "screw in" style plug caps with the auto style wires? thanks for any and all in put
(82 xj750 maxim)

 

If you're going to go this far, spend the extra money and get a set of replacement coils instead of the stockers. A nice set of Accel or Dyna coils will set you back around $150, but it's worth every penny. Better coils, stronger spark, and you can replace wires anytime you feel like it. Only down side is you'll have to fabricate a mounting for them yourself -- they don't fit nicely.

 

The salvaging of your old coils should be a last resort effort if you haven't the money to score the aftermarket units. Check out the forum search for more on this topic, there was a post for how to do this with the X types but I haven't seen it done on the earlier units. I would have done my own this past year but the local bike shop wanted me to buy 50 feet of copper core 7mm ignition wires at $1.50 a foot. I can't use all of it so I passed. I would avoid using the graphite core as the internal resistance is different (I can't remember if it is higher or lower in resistance) and will not work well with our coils, possibly burning them out. I'll see what the bike shop online will do for me. NGK screw on ends are a good way to go but I think you will find they are not happy with the graphite core.

 

Dyna coils, at least for the X, is the way to go. I have seen complaints about the Accel brand. (Dyna coils DC1-1) Copper core wiring is also essential, which Dyna also sells. Resistor plug caps rated at 5K Ohms from NGK. Possibly you can find more specific data for your non-X.

MaximX examples:
http://gary.singular.org/maximX/ (Coils links)
http://tinyurl.com/j5nw3

Z

 

What about when you go from non-resistor plugs to the resistor type? Then instead of resistor caps, you need non-resistor caps. I want to go with the Dynatek DC1-1 coils, a good 8mm carbon core shielded plug wire, and an NGK Iridium BPR7EIX plug. Anyone done that yet? The standard NGK BP7ES is a non-resistive plug, hence the 5Kohm resistor plug caps on our OEM setups. I guess to test this out I could twist off the 5K caps and install some non-resistive caps and then the NGK Iridium BPR7EIX plugs.

 

I've done it to my FJ600 using a pack of Accel graphite core. For the low price of $50 I got wires for 8 cylinders, some of them super long, enough to do the whole wire replacement twice. I posted some details here:
http://www.gtamotorcycle.com/forum/viewtopic.php?t=55579

I've been running on these wires for a few months, with the old coils, and no problem whatsoever. YMMV, so caveat emptor, whatever, use at your own risk. I personally had a good experience old coils+new graphite core wires.

 

Yes, I believe that would work, switching to resistor plugs and non-resistor caps. We're simply looking for around 5K Ohms of resistance between the coil and the spark. The difficulty in trying to use carbon core wire, IIRC, is that it adds resistance to the equation.

Z

 

Yes, the carbon core does add resistance, and also more electronic interference if cheaper wire is used. Best to stick with a namebrand. I think I'll do the cap/plug replacement first to benchmark my upgrade. I suspect there will be minimal improvement. The big performance boost will come from the coil upgrade.

 

Actually, I think you are looking for 15-20K resistance in each individual plug cap/plug wire combination. I have not verified the following information yet, but I read here in another forum about the plug caps being of differing resistance. Since the wires to #2 & #3 cylinders are shorter, they have less resistance than the longer wires to #1 & #4 cylinders. So...the caps on #1 & #4 cylinders are 5K ohms (longer wire, more resistance, so less resistance in the cap), where the plug caps on #2 & #3 are 10K ohms (shorter wire, less resistance, so more resistance in the cap). You have to make sure you have the correct caps on the correct cylinders! I will verify this when I return home this evening.

When going to aftermarket performance coils, this can be easily remedied by making all wires the same length - or - using different resistance wires, as long as the wire/cap/plug combination results in equal resistance.

Has anyone had experience with the new DC1-2 miniature coils? They may fit better in place of the OEM since they have the same wire output setup. I'm on the phone now with Dynatek (on hold of course) to find out if they are a suitable replacement.

Later,

Michael

 

I would definitely double check, to be sure, before you throw 20,000 ohms of resistance into the mix. I've never heard any number close to that. You may end up with as much spark as your bad coils. :wink: Just straight 5,000 ohms across the board.

There would be no math involved if you stick with copper core wires (recommended) which offer the working value of 0 ohms resistance.

My understanding, from someone who actually tried them, is the mini coils don't have enough kick.

Z

 

I love those ... and they have the clip type thing in their cap for use with the hourglass nut on top of the plugs ... which my champions come with stock ... overall ... sweet ... my eli 1000, my kaw 454 etc loved it. I might splice into mine and run those wires ... now are the wires non removable types ... I hate that ... but like on my virago 535 I used a sawn off screw to splice in and zip ties on either side of the screw to hold it tight and electrical tape in oodles to hold it all and then put a radiator hose over it all ... yea butt ugly ... I mean Rob Schneider butt ugly ... but it never missed sparky ...
Cool.
Srinath.

 

Dynatek did recommend NOT going to the DC1-2 coils. He said they will work, but the coils will overheat and burnout, and possibly destroy the bikes ignition electronics. He also said the resistance in the wires/cap & sparkplug are negligible when taking into account the amount of voltage present in the spark. He commented that the resistance in the wire/cap/plug is there primarily to suppress electronic interference.

The best fit for our OEM coils is the DC1-1, and to use the Dynatek carbon core wires (5K ohms/ft), a non-resistor cap and a resistor plug. If sticking with the copper core wires, than a resistor cap/non-resistor plug or non-resisitor cap/resistor plug will work. He also said any brand of carbon core wire will work as long as it's close to 5K ohms/ft. That will ensure any electronics on the bike will not receive excess interference.

So I looked at my caps during lunch, and #1 & #4 are NGK, and #2 & #3 are Denso. Didn't measure the resistance yet, that tool is at home.

 

Does anyone know where to find some 7mm non resistor screw-on 90-degree sparkplug caps? I need to find some for the first phase of this test. I already have the NGK Iridium BPR7EIX plugs. They did not work well with the resistor caps.

I guess I could go with the crimp on end and the large sparkplug top, but I don't want to violate the integrity of the OEM coil wires.

 

My local motorcycle shop (large dealership) carries the entire line of NGK plug caps. All different shapes and sizes, and resistor or non-resistor.

Z

 

Could you grab the part # for an NGK 90 degree screw-on cap that is non-resistor? Then maybe I can find a distributor on the net. My shop is several cities away and is closed hours before I could get there.

 

Check out MPS Racing, out of Florida. Great people, low prices, and fast shipping. It was the lowest price I found, away from ebay, on DC1-1 Dyna coils. (I had better luck calling, rather then surfing their site.)
-- http://www.mpsracing.com/
-- (407) 330-9727

Also try MotoGrid.
-- http://www.motogrid.com/
-- (877) 668-6474

Here's a guide to choosing your NGK plug cap. You'll be looking for something like LBE* or LBF*
-- http://www.spark-plugs.co.uk/graphics/i ... symbol.jpg

You can see pictures of the rebuild of my MaximX, including the coils, wires, and plug caps, by following the link in my signature.

Z

 

Well, I measured the sparkplug resistor caps today, and they are opposite of what I originally read. The #1 & #4 cylinder boots are 7.5K ohms, and #2 & #3 were 5K ohms. Hmmmmm....My #1 & #4 sparkplug boots are not labeled as to who the manufacturer is, but # 2 & #3 had Denso Tokai on both the boot and the rubber seal. I'm wondering if the PO changed them out at some time.

 

I've bookmarked mpsracing.com before, as they had the lowest price on the Dyna DC1-1 coils. I'm looking for something else on the wires though. I have the larger gas tank on my bike and it rides a little lower. I will definitely need the angled boots, maybe not as severe as 90 degrees, but angled nonetheless. Accel makes a black 8.5mm carbon core kit that I will probably end up buying.

Thanks for the info!