Topic: Resistance Question?

[KAndrew]

Hello,
I have a '74 CB750 that I've recently spent the last 2 years doing a full restomod makeover. It seems to run fairly well, just a few minor tuning issues and I think she'll be done. It's got a 836 kit, hot cam, ported/polished heads, balanced, beefed up and finally broke in. One part I splurged on but got bit was an "optical" ignition that would shut down as soon as it got warm. After messing around, I decided to cut my losses and put a stock Honda points system in but with 3ohm coils (magna's). It doesn't start and idle as well as with the optical system, but I can get further than 10 miles down the road so I'm not complaining. My question (finally) is what considerations have I missed regarding resistance to the plugs? I'm using resistance type plug wires, and 5k plug caps. I'm not using resistance plugs. Is this wrong? Too much or not enough? The bike does run, so this is more of a curiosity type question than anything else?

PS: being that this is my first post but I've been lurking this site for years, THANKS to EVERYONE here. Your combined knowledge is such an asset and this is a great community!

[Deltarider]

I'm using resistance type plug wires, and 5k plug caps. I'm not using resistance plugs. Is this wrong?

Im afraid resistance type plug wires is a no no for our bikes. Not having personal experience with them, I pass on what I heard from a Honda mechanic specialised in old bikes. I suppose the graphite core becoming brittle is the problem, but maybe there is more to it.

[KAndrew]

Thanks for the reply.  I'll get a new set of wires asap but I have another question and need to correct my first post.

Currently the bike has suppression plug wires (came with the Power Arc kit which I removed), 5K spark plug caps, and it DOES have resistor plugs: Denso X24ESR-U's.  So before I run this bike much more and maybe hurt my new coils, how should I set it up?

Thanks,

[Alan F.]

Solid wires, 5K resistor caps and non-resistor pugs is stock.

I'm tempted to answer the thread title question with, "Futile".

[KAndrew]

Nice! 

I will make some changes.  Thanks for setting me straight.

[TwoTired]

The stock wires were aluminum stranded.  Pretty low resistance for the short lengths they have, and likely better for the screw on plug caps that were used.  The plug cap resistance for most 750's was 5k  With some models having 10k.  It really doesn't matter where the resistance in the coil secondary circuit is, the wire spark plug or plug cap, as long as it is in the 5K-10k range per ignition to plug path.  Resistance wire, due to the different lengths will make the circuits different per branch, which I feel is undesirable.  Plus they don't age nearly as well a stranded solid core wire.

Not sure why you favor 3 ohm coils.  Did you get a compression increase with your engine mods?

Cheers,