High performance ignition coils have been around for a long time. In the earlier days of motorcycling they got a lot of good press because they did in fact improve engine performance. And they did this by making carburetion better. Yes, carburetion. Read my 60/40 Rule article. There is a lot of overlap between fueling and ignition. The symptoms for one mimic the symptoms for the other, for example. The classic less/more air tests serve to pare down the possibilities between the two.

The 60/40 Rule

So hipo ignition coils were long a fave among motorcylists. But with fuel injection that stopped, not because fuel injection bikes have better ignition--they actually have weaker ignition than ever before--but because the fuel injection made fueling so much more precise that mongo ignition held no promise of improving combustion.

The factory CBX ignition is TPI, which is Honda's version of transistorized Kettering, which is simply point ignition without the points. See my article on the seven types of ignitions used on powersports products since about the 1950s.

Ignition systems compared
The CBX ignition

TPI is exactly the same in its strengths, weaknesses, and operation as point (Kettering) ignition. "Electronic" (TPI) ignition offers no more power, no more accuracy, no more reliability. In fact, if it wasn't for emissions laws that mandated longer periods between maintenance adjustments, standard Kettering would never have become obsolete. And the Dyna S (standard, low performance) ignition is nothing more than an aftermarket version of Honda's TPI. With one caveat, which I will mention later.

In fact, most installations of Dyna ignitions on CBXs result in less performance and durability than the stock system they replaced. Here's why. First, the Dyna coils come with resistive plug wires, you know, the kind you had to replace every few years on your car, or at least your dad did in his day. That's because being carbon-based the wires degrade over time, increasing in resistance. But worse, since there is no real wire in that wire and the ends are crimped, this means especially on motorcycles, the connections start out compromised and only get worse with time. Second, when folks install Dyna coils they inevitably crimp the battery connections. Again, crimping is a very bad idea on powersports. Nearly every one of these installations I end up re-doing. Third, Dyna never made an ignition for the CBX. The Dyna modules (trigger assemblies) sold for the CBX are actually converted parts meant for Kawasaki triples. As such the mounting screw locations are quite a bit off. If installed as-is and the timing not checked, the CBX will run its ignition 10 degrees over-advanced. This is not the best thing for an already too-hot engine. Slotting the mounting holes to correct the timing of the Dyna is mandatory.

Now, the caveat. There is a good reason, despite all of this, to run a Dyna ignition, beyond the fact that replacement Honda pulsers and coils are getting obsolete. Simply, it's the fact that the Dyna houses its transistors inside the module and Honda transistor boxes ("spark units", "igniters") are going bad and so far the two or three aftermarket igniter choices have proven very unreliable (i.e. they last about 1 year). In short, the best and at present only reliable replacement aftermarket igniters are the ones inside Dyna's ignition module.

One more thought (bonus!). Forums everywhere are talking about the fact that vintage Hondas drop a volt or more (typically 1-2 volts, which is acceptable, and often 3-4 volts, which is not) between the battery and ignition coil. They promote installing a Bosch type relay to up the voltage a bit. That is okay. I have an article on this too.

The relay mod

The problem is, this is a bandaid fix, rather like forcing a drunk to drink a lot of coffee in an attempt to get him sober. He may open his eyes a bit wider, but he is still drunk. The same thing with this relay mod. The problem it is masking and not solving is deteriorated wiring harness connectors. They are easy to fix, and this should be done rather than jumping over the whole harness with a relay.