Topic: What ignition leads should I be running?

[Gizmo]

Im hitting a wall. I have a Dyna S, 5 ohm coils, with DR8EIX iridium spark plugs and none resistive caps. Do I need to run graphite core wires? or will copper core suffice. Is the 5k ohm of resistance in the plug itself enough?

[RAFster122s]

I am afraid that you might have trouble with iridium plugs on a carburetor equipped bike unless it is tuned very well.

Usually you want either resistor caps or resistor plugs but not both.
Copper core wires should suffice.

[Deltarider]

Im hitting a wall. I have a Dyna S, 5 ohm coils, with DR8EIX iridium spark plugs and none resistive caps. Do I need to run graphite core wires? or will copper core suffice. Is the 5k ohm of resistance in the plug itself enough?

Yes, 5k is enough and graphite core wires are an absolute no-no on our bikes because reliability in the long run will be severely compromised.

[DaveBarbier]

I’d also be weary of iridium plugs. Use copper core wire. If you end up having issues you can’t figure out, switch to standard plugs of the heat range that’s in the manual. See if that helps. Recently there was a member chasing some weird ignition issue an after a few pages of trouble shooting he mentioned iridium plugs, switched to standard plugs and the issue vanished.

[1976cb750f836]

I'd use standard ngk resistor plugs with copper wire.

[Gizmo]

Thanks very much for the feedback guys! I will give the standard plugs a try.

[RAFster122s]

Make sure you are buying your NGK plugs from reliable sources, lots of counterfeit plugs out there.  Some have been reporting issues with new out of the box nguyen plugs.  Makes me want to order Denso u-groove plugs instead...

[Dunk]

You are running the hot ticket for ignition setup. I have the same on my bike along with solid core wires and it performs great. Dyna S and iridium plugs each make a big difference in cold starting and cold idle as well as hot idle performance and smoothness. The iridium plugs and Dyna S make the bike much more tolerant of a less than ideal mixture. I've run 3 ohm coils, then switched to 5 ohm to minimize unnecessary current draw, I noticed no difference. my engine is a K1 with a ported head, but otherwise nothing fancy done to it.

Those are resistor plugs and have enough resistance in the plug itself, same as stock early caps (5k ohms). You want to run non resistor caps. 10k ohms works fine if you're running resistor caps, but the caps quickly wear and gain resistance along with the plugs gaining a bit of resistance over time as they wear. Much more than 10k ohms and you'll get misfires. I learned this the hard way as I at one point ran graphite core wires, 5k ohm caps, iridium resistor plugs and it was great at first but eventually has problems with weak spark.

[Gizmo]

Thanks Dunk! it is great to hear others set-ups and their real world experience with them. Very helpful.