I did this writeup a few years ago for KZR but I think it is worth reposting here for education (and because I put a lot of work into it!)
In the past two weeks I have been blessed/cursed with running points, then a Dyna III ignition, and then a stock KZ650/750 Kawasaki Electronic ignition system. It started with the appeal of upgrading to electronic (Dyna), and ended with kawasaki electronic because of charging problems with the Dyna (thanks Rev!!!).
--== Points ==--
We all love cleaning pitted points and gapping them, right?
Verdict: They need maintenance and your timing gets slowly worse until you adjust them. However, you get to tell all the cool kids you still have points and gaps!
--== Dyna III ==--
I installed the Dyna III about two weeks ago and had the bike running nicely. Unfortunately the bike failed the charging system test with a fully charged, new battery!
Installed Dyna III:
Idle - 11.9V
4000rpm - 12.6V
After much head scratching I got a DC clampmeter to easily measure current in the system:
from reg/rec - ~1.0A (Amps)
Battery - 9A OUT
Main fuse (whole bike) - 9.75-10A
from reg/rec - 11A?
Battery - ~3A IN
Main fuse - ~9A
(I guess it is +/- 1A accuracy)
Breakeven point on the battery charge was about 2000rpm.
- Stock coils (~4.3ohms each)
- H4 headlight (55W), always on (Canadian bike)
- standing lights, dash lights on
Verdict: Battery is discharging rapidly during idle, though with enough high-speed running (approx 4-5 mins at >4000rpm for each minute at idle), battery can stay charged. Spark could be weak from the lower system voltage.
When I removed the headlight fuse and ran without that 55W load, the battery stayed charged for that 3-day test.
loudgpz has said many times that the Dyna has a very long (300 degree) dwell angle compared to about 180 for point. This extra current load from Dyna seems to have pushed the Canadian KZ650's charging system over the top, and the battery begins to suffer.
My immediate solution was to run without the headlight (during the day!). However, for safety a daytime light is still a good idea. I am designing a simple LED addition to the H4 headlight to make a permanent 20mA "city" light. On Canadian bikes this requires addition of an on/off switch for the headlight so you don't have to keep installing the headlight fuse after the sun goes down.
--== Kawasaki Electronic Ignition ==--
I was fortunate to come across a Kawasaki Electronic Ignition, apparently from a KZ750E2. This bolted right in with some minor electrical modifications.
Battery - 12.5V
Main fuse - 6.75-7A (H4 headlight on!)
Battery - 14.6V
Main fuse - 6.25-6.5A
I stopped the testing there, jumped for joy, and went for a ride. The 14.6V tells me the reg/rec is starting to interrupt the stator power and it is no longer running at maximum output all the time!!!
On the ride, the bike seemed to hold idle better (maybe coils don't get as hot?), and there appeared to be more power in midrange (higher voltage to the coils?).
Verdict: An average of about 3A less power use than the Dyna III setup could only mean a more efficiently running motorbike.
Finally, the latest 1981 IC technology on my bike - just like in the Commodore64!
The Dyna's high dwell angle taxes the charging system of the KZ650C2. Though not immediately apparent, it is possible that it would severely undercharge the battery over time. I recommend all KZ650s with Dyna installed perform a charging test (particularly Canadian models), and ensure they charge their batteries weekly if the do not pass and there is frequent city riding.
Alternatively, with Dyna III, you can cut out the headlight and install an alternate, low power, city light to provide charge to the battery. However, your coils will still be drawing far more current than they were designed to. (BTW the H4 headlight is a VERY good idea regardless)
Alternative 2: build your own IC Igniter that reads the Dyna signals and can reduce the dwell angle to <200 degrees (it can be done).
Ultimately, Kawasaki Electronic ignition is the way to go!