Topic: NGK DR8EIX Iridium plugs, what coils to run?

[Soos]

I just got my Iridium plugs today!
Could there possible be a difference in performance from running these with my Dyna 3.0 ohm coils, or with the stock 3.0 ohm coils that came with the bike.

I plan on running these plugs on my 650 i recently finished a hillbilly head job for(did it all myself) and is bored out to 61mm(750F pistons).


The 650 uses electronic ignition, and stock coils are 3.0 ohm if i remember correctly.
I do have the option to run with a good pair of 28 year old coils, or 1 year old Dynatek 3.0 ohm(green)coils. Both are going to be running on new 7mm copper core wires, and fairly new plug caps(5k resistors). Spark gap will be by the book.


l8r

[Frankenkit]

how did this go?

[Soos]

Well, to say the least.

I have since dumped the CDI system that is stock, and hooked a DYNA2000 unit up.(whoo, freedom from the dreaded melted CDI units!!!)

I am currently running 2.2 ohm grey dyna coils, and iridium plugs.
Had to omit the resistive boots for the plugs though, as the plugs themselves are resistive automotive plugs already.


Right now i'm just itchin' to get those nice new Michelin Anakee treads on my rims....


l8r

[Duke McDukiedook]

The dynas should have a higher output which should mean a better spark.
Man, iridiums on an 80's 650, I guess you have some $$$ to burn.
Go with your dynas as long as they work well with the copper wire, since you are using premium plugs.

[MRieck]

The dynas should have a higher output which should mean a better spark.
Man, iridiums on an 80's 650, I guess you have some $$$ to burn.
Go with your dynas as long as they work well with the copper wire, since you are using premium plugs.

The Dyna 2000 requires supression wires. Dyna S is OK with the copper core.

[CB500_k2]

I suspect stock ignition and coils would work just great with iridium plugs.  I have been running iridium resistor plugs in my CB500 for 3 years.  My setup includes resistive plug caps, 3 ohm after market coils with 1 ohm resistors in series with each coil to limit current draw and standard points.  The bike has run great, easy to start --- no problems at all.  It is my understanding that the fine iridium wire electrode will provide an acceptable spark at lower coil voltage.

[Deltarider]

I have been running iridium resistor plugs in my CB500 for 3 years.

May I ask, have you been running "7's" or "8's"?

The reason I ask: I've always used "8's" in my 500 but they can foul when you ride too long low in rpm like in the city. For me the only reason I might change to paladium, platinum or iridium plugs is that - maybe - their "8's" stay cleaner under these conditions.  Sparkplugs have only two things to do: 1. Ignite a tiny bit of mixture and 2. stay clean. The rest is humbug IMO.

[sparty]

I have been running iridium resistor plugs in my CB500 for 3 years.

May I ask, have you been running "7's" or "8's"?

The reason I ask: I've always used "8's" in my 500 but they can foul when you ride too long low in rpm like in the city. For me the only reason I might change to paladium, platinum or iridium plugs is that - maybe - their "8's" stay cleaner under these conditions.  Sparkplugs have only two things to do: 1. Ignite a tiny bit of mixture and 2. stay clean. The rest is humbug IMO.

Delta,

Iridium plugs DO make a difference with good coils and a electronic ignition, not so much for a stock system.  In my hotted up engine I initially ran NGK regular plugs and then made the switch to iridiums.  It was a difference I could actually feel and see when I pulled the plugs.  The plugs were cleaner and so was the top of the piston even at low RPM riding.

[Deltarider]

The plugs were cleaner

I'm interested in "8's" (or "24's" for that matter) that will stay clean at low rpm.

[sparty]

The plugs were cleaner

I'm interested in "8's" (or "24's" for that matter) that will stay clean at low rpm.

My engine, with its ported head and oversized valves is very efficient so the 8's run very clean.  That may not be the case with a stock engine.  However the iridiums are supposed to produce a better spark that allows the mixture to burn more completely/fully, so that may make a difference in a stock set-up.  Remember these fours run their best in the upper RPMs, if you are running low RPMs, you are not riding in the sweet spot for these engines, stock or not.  So no matter what plugs you use, if you lug the engine, you will have a dirty spark plug.  These engines will run around the world many times at 6000 to 8000 RPMs without any problems.  Riding below 5000 will cause deposits even on a hotter plug.  On an 8, they will eventually foul.  Running those higher RPMs will allow the fuel and oil to burn off more completely leaving less carbon on plugs and piston dome.  It is that simple.

[Deltarider]

These engines will run around the world many times at 6000 to 8000 RPMs without any problems.

That's what I've been doing. My problem is that a "7" is a bit to hot for that and the "8" will foul in periods the bike is used at low rpm.

BTW a spark plug does not ignite "the mixture" just a bit of it.

[sparty]

These engines will run around the world many times at 6000 to 8000 RPMs without any problems.

BTW a spark plug does not ignite "the mixture" just a bit of it.

I know that the compression is part of the equation, but a better spark means more of the mixture is burning, thus a more complete burn and less unspent contaminates that lead to build up.

[Soos]

The dynas should have a higher output which should mean a better spark.
Man, iridiums on an 80's 650, I guess you have some $$$ to burn.
Go with your dynas as long as they work well with the copper wire, since you are using premium plugs.

this was an old thread kit brought up...
 


And I am running 8's
Happy so far.



Mmy 650 has been one fun money pit.
...bored 1.2 mm over(652cc's), head job, valve job(radius ports), dyna2000, longer swingarm, powdercoated frame and rims(and a few other bits), the iridium plugs, dyna copper core wires(came with the kit, what can I say MReik?),  2.2 ohm coils, tapered neck bearings, custom swingarm bushings, the dyna2000 does not come in a kit for the cb650, so I had to modify one to my needs, new shocks, recovered seat, 4-1 "superflow" made in '81 NOS exhaust(added a O2 sensor bung), dual disk upgrade, plastic front fender(stock was steel), KZ1000 MC...
Thats just the list offhand.

And I like it looking grungy, all flat black. Whose bike they gonna steal, the fast CBRR, the flashy harley, or the 30 year old honda thats dirty as all sin...


A LOT of the above mentioned work was done by myself.
Yeah.
I guess I got a $$$ addiction with this bike. Ebay is an evil place with bonus money.
Gotta love big buisness greasing the wheels of the little man.
Actually thats where 90%+ of the money came from past the initial purchase of the $60 titled rolling chassis with a motor and carbs.
You should see the parts room in my garage.
 



Anyways....





l8r

[Soos]

These engines will run around the world many times at 6000 to 8000 RPMs without any problems.

That's what I've been doing. My problem is that a "7" is a bit to hot for that and the "8" will foul in periods the bike is used at low rpm.

BTW a spark plug does not ignite "the mixture" just a bit of it.

A shadetree fix(have heard, not tried mind you), go with the "7"'s , and gap them more.

Do you have a clymers cb650 repair manual?
It has a good page on 1/2 steps of different manufacturers you can run.
Another thing listed in that that REALLY has piqued my interest several times is using 2 plugs of one heat range on the 2 outside cylinders, and 2 of a slightly (1/2 to 1 full step) hotter/cooler(?) plug to get best performance due to the 2 inner 2 cylinders running hotter than the outer 2.



l8r

[CB500_k2]

Delta,

In my CB 500 I am running Denso IX22 s.  They stay clean and do not appear to be too hot. I live in the country so the RPM rarely falls below 3k.  I run a stock airbox with a K&N filter element and stock jets.

[78CB750CAFE]

I find I get a realy good spark with my current set up:

3 0hm Dynas w/ Hondaman 1 0hm resistors
Accel 8.8 sheilded wires and caps
Irridium resistor plugs... was running dr8eix in the summer, dr7eix now

[Frankenkit]

Since I can't let this thread die, it seems...
the DR8EIX plugs are resistor plugs, so I'd have to pull the resistor segment out of my caps, right?

[78CB750CAFE]

or just replace the caps w/ non resistor ones.

[Frankenkit]

Where would one find those?  I've heard tell of being able to pull the resistor out of NGK resistor caps and replacing it with a metal slug, but I wouldn't have a clue where to get said slugs etc.

[78CB750CAFE]

FLAPS should sell Accell or other brand replacement caps, and most MC shops sell NGK boots. With auto bootsjust be sure they will match your wire diameter and you will probably have to get straight ones, since most 90 degree auto boots won't make it to the 2/3 spark plugs on a CB.

[Soos]

The dyna wire kit I bought had automotive style crimp on ends.
No boots needed.
Just rubber covers for the ends where it connects to the spark plug.

I just screwed the thing that comes with the spark plugs on the  threaded tip for the connector.
Completely eliminated the spark plug boot.
But I ripped one of my spark plug covers(?silicone rubber?) and a electrical storm ensued.

I quickly changed setups to side gapped plugs(with an older set of wires with resistive spark plug boots) due to not having the $$ for the new silicone spark plug cover for the end of the dyna wire.
I basically put the wires I hed on before the swap to the iridiums back on.
Had a itch to side gap them just to see how or if it would make a difference.
It was that or buy new plugs... and again I was tapped outta $$ at the time.

Will go back to the iridiums one day, but these side gapped plugs seem to do quite well so far so I will stick with this setup until I have a spark plug failure or something.


l8r

[Scrubs]

By the way, does anyone know if the - Grey 8mm silicon supression core - plug wires from Dyna
are supplied with resistive caps or non resistive?

[Soos]

They don't have the spark plug boots you are expecting.

They have ends you crimp on to fit to the normal car spark plug end.
Exactly how a cars are, or the '70's and '80's vehicles I am familiar with.
the spark plugs will need that little aluminum widget screwed onto the end of the spark plugs to work with them though.

But you can use your existing spark plug boots with the new wires though.




l8r

[78CB750CAFE]

soos-
I am pretty sure I have spare accell sttr8 and 90 degree boots, if you have the copper/brass whatever crimp on bits I can send 'em to ya.

Drew