Over 20 years ago, I decided to make my own, as the market did not provide a system I would feel comfortable with in my journeys to far away countries, where, in the event of a failure, I would not have a back up. Mine is just an impudent copycat of the well known Velleman K2543 kit (X2). In this setup the breakerpoints switch the control current, reduced in amps to just enough to stay clean. My breakerpoints have done som 60.000 km now. The power switching is taken over by a socalled Darlington transistor, designed back then, especially for this purpose, by Texas Instruments. It can switch up to 500 Hz/s! In our two coil set up, switching at 10.000 rpm is only a 167 Hz, so lots of reserve.
For a good understanding, read the following.
The stock Kettering ignition as designed by Honda is more than adequate to give the energy needed at the sparkplugs electrodes at all speeds. Realise that all Mike Hailwood's victories were on bikes with breakerpoints. EI's in general may give some improvement at starts and in low and very high rpms. Do not expect a gain in midrange however. The spark is only needed to ignite just that little bit of mixture around the plug's electrodes. From there the travelling flame front will do the rest of the combustion. Imagining this process in slow motion, will help you understand. Some folks proudly claim they have a spark 'of a welding torch' and even widen the sparkplugs gap. They only demonstrate their ignorance. The only result will be a much quicker eroding of the sparkplug's electrodes.
Typical spark duration of my kit is 2000 μs (2 ms). In tests it performed even better. The rise time of the Velleman is pretty short with only 25 μs (see graph). All in all, lots of reserve.
My kit is stored high and dry where there is no risk of vibrations, high temperatures or water ingress. Maintenance is limited to check the cam is still lubed, say every 6000km. At the start of every season, it is my habit to do a quick test to check if the dwell angle is still constant at all rpms.
