my buddy just bought himself a '77 cb750 that had the dyna s in it.
it's doin something weird though, i'm not real familiar w/ this system so this may be normal; when i hook up a timing gun to the left coil (outer cylinders) it lights, but when i hook it up to the right coil (inner cylinders) it won't even light up to tell me if they're timed right.....
this is a pickup type gun that you hook to the battery and clamp the little pickup to the spark plug wire with the wire plugged into the spark plug.
...and why is the gun not registering if there is spark against the motor?
Some inductive triggers on timing lights are pulse polarity sensitive. You could try flipping the inductive clamp on the ignition lead.
Back original post...
The dyna s will draw more power from your charging system, as it leaves the coils in the on state during each crankshaft revolution far longer than points do. This results in about a 30% more power draw from the ignition system on the charging system. It's not much impact on the 750's with its bigger alternator. But, on the 550, it could be noticeable, particularly if the wiring and switches, etc., haven't been getting any attention since new.
I always thought the Dyna-s too expensive for what it does. So, I still have points on all of mine. (And a small stock pile of new ones). Still, I've been tempted from time to time as I am a gadget geek. But the points system still serves admirably. I very much like the idea behind the Hondaman unit, as I have no doubt that it would reduce even what paltry attention is now required by the stock points. But, if I got one of them, the other 9 bikes I have would be jealous. Multiplying the price by 10 has made me realize how easy it is to maintain the current stable of points I have.
Cheers,