COPs Spark Plug/resistor questions

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Ost85vmax

Well-Known Member
Joined
Apr 7, 2011
Messages
216
Reaction score
6
Location
Madison
So the PO had Knology Hotwires and Splitfire 416c plugs in. I am now switching over to the COP's setup. So now going from resistorless plugs to plugs with resistors correct?? My other questions are:

Which spark plugs should i use with the new denso COPs?

Whats your suggestions on running resistors inline to match the resistance on the original coil packs? I herd both to match the 3ohm pack resistance and some say they have not and things are fine?

I have the NGK iridiums sitting on the work bench but.....waiting for the input from some you who may have more experience.

Any input is greatly appreciated!
Thanks all!
 
The resistors are in the plug caps. Dismantle them and remove any corrosion from the spring, brass disc, resistor, spark plug socket etc. and check the resistance value, it's probly already spec'd to oem.
 
if your running the dynatek 3000 aftermarket ignition module, you will most definately want to consider inlining resistors so that the box sees the 3 ohms, else you'll playing with fire--i.e., most guys running the dynatek/cops combo have fried their units.

if your not, then like you've prolly read, it's not necessarily mandatory, and guys have driven enough miles on a resistorless setup to have taken them across north america and back, but then again there was that ONE case I recall, where a dude fried his stocker module somehow--perhaps due to an unrelated reason, but nonetheless imo what does it hurt to put some resistors in? they aren't but a handful of dollar bills at most and cost you the same amount of time to knock back a couple beers to solder them in.

which type of spark plug? you've just asked a question that resembles the same lines as "what oil?", "what coolant", "what gas?", "what wax?". my advice: put in what you think your wallet is willing to justify.
 
Not really a 'resistorless' set-up Ninjaneer if the plug caps are unchanged.

Here is a pic of a MaximX plug cap, the V Max is identical internally.

The resistor is 3rd from the left. Removing the resistor and inserting a brass rod would make it resistorless, and swapping for a different one would change the resistance value.

1-maximx_plugcap_and_parts.jpg
 
I'll have completely new plug caps as I am ditching the coil packs and the nology hotwires and going to Denso COP's. That's why I ask which spark plugs. Stock plugs have resistors to reduce rf interference and the old hotwires are to be used with resistor less plugs. So I am asking if I go back to plugs with resistors. I have iridium plugs now with resistors I will use.

Danny, thanks I'll measure the resistance across my Denso COPs and if they are not 3ohm hopefully I can swap the resistor inside it?? If not I'll just solder one inline with the wiring harness.

Does this all sound accurate?

Thanks for all the input, time to leave work and go work on this project.
 
Not really a 'resistorless' set-up Ninjaneer if the plug caps are unchanged.

you're absolutely correct. an unfortunate choice of word on my end. i simply was referring to the use or non-use of a supplemental resistance.
 
I have read some on the COPs conversion here on this forum and one member makes a very nice adapter harness, very professional looking and a reasonable price kit even for used coils. I have considered doing this but I always come back to the question, what is to be gained? I would assume the plug coils have somewhat higher spark energy but I have never found proof that there is any measureable performance gain. The vmax has one coil per plug anyway so you wouldn't be eliminating coil saturation like you would on a car that had a single coil for all cylinders. Has anyone shown even marginal proof this really does anything, dyno comparison or a time slip? Just curious
Thank you

Mike
 
honestly, ever since "bird of prey" pioneered the mod a few years back, i have yet to see any sort of performance measurements. i am thinking that the lack of evidence is because COPs really don't offer you much as far as performance. some report that their bikes fire up easier, and i recall reading that one guy said his dyno technician said that his COPs-modded Max was one of the easier to tune (whatever that means). But those observations are subjective. Substantially speaking, what you do gain is the ease of changing out a coil not to mention relief on the wallet. Stock coils are notorious for cracking and some guys will simply repair them with epoxy or whatever. Some guys will report that their coils are beyond repair and need to replace them. One stock coil cost 70 bucks ($280 for 4) and count your lucky stars if your only replacing the #2 and/or #4 coil that seat above the battery, because replacing one of the other two is a PITA. The cost of 4 COPs is on average $50 and if you ever need to replace a bad COP, just pop it off, and then plug in the new one and you're ready to play in a matter of minutes as opposed to units of hours and no need to bust out a wrench.
 
All the sport bikes I have seen lately run cops as opposed to our old style coils. Wonder why ?

http://www.aa1car.com/library/copign.htm

After reading this article, the best that I can tell, is that they keep manufacturing costs down, improve MTBFs, and reduces the chances of lean misfires. I'll keep looking for benefits associated with performance claims, like HPs and/or foot-lbs, but I'm a little skeptical that such benefits will appear on our bikes.

Hey, don't think I'm shooting down the mod. On the contrary, I did it and have no regrets. After making my own harness and getting some eBay COPs, I was still able to replace my cracked stock coils for less than buying new ones. Plus it has that "cool" factor.

Regards from my Taptalking Hercules Android
 
Last edited:
The COP's mod is easier maintenance and less prone to failure/poor running.
There is no real performance gain.

The iridium plugs are fine if you use the ones to suit the v-max.
Putting the resistors inline on your wiring adaptors doesn't hurt anything. The only downside of them is that they waste a tiny bit of heat energy. So, as a precaution they are fine. Lot's of people haven't worried about that precaution. I put them in and they work fine.
 
The COP's mod is easier maintenance and less prone to failure/poor running.
There is no real performance gain.

The iridium plugs are fine if you use the ones to suit the v-max.
Putting the resistors inline on your wiring adaptors doesn't hurt anything. The only downside of them is that they waste a tiny bit of heat energy. So, as a precaution they are fine. Lot's of people haven't worried about that precaution. I put them in and they work fine.

Awesome info. I do have the plugs spec'd for the vmax so it now all seems pretty straight forward.
 
What is your gap set at on the plugs ?

Great question, does anyone have an answer to what is recommended for a gap setting?

Also, when looking into the cop where the wiring harness attaches is the left or the the right tab the positive connection?
 
^ The Kit from I got from Sean (Made by Gannon) said the Gap should be .026.
It also came with the Stock NGK Plugs, which is all I have ever used on my Max.
 

Latest posts

Back
Top