TOPIC:

Does anybody know of a coil per cylinder kit suitable for the kz650 or is this something that will take some creative engineering?

Gee... that would require 4 sets of points or 4 sets of detectors under the ignition cover. Sounds like a 4 handed job for a two handed man.

Don't think that will work... and probably not much return on the investment if it could.

My 2 cents.

Best of success.

Thank you for your response! I figured as much. This is actually (at the moment) not for performance related considerations but rather for a proof of concept wager I have going with a peer. What I really need is just to arrest the waste spark so in that respect I realistically don't need cylinder independent coils. I should have been more specific, I apologize.

I suppose what I should do, then, is simply come up with a system to choke the waste spark in the existing system.

the "wasted" spark is because bikes use the crankshaft to mount the cam that opens the points. It turns once for every rotation of the pistons, but a four-stroke cycle engine only needs a spark EVERY OTHER rotation of the crankshaft (compression stroke).

Sparking on both the compression and exhaust stroke doesn't hurt anyhting and makes the ignition simpler. To spark only when you need to would require a gear reduction drive so the shaft driving the cam opening the points ran at half the speed of the crankshaft. Possible, but kinda complicated when the other spark is harmless.

Virii wrote:

I suppose what I should do, then, is simply come up with a system to choke the waste spark in the existing system.

Impossible for points driven off the crankshaft, which is what a 1977 KZ650 had in it.

Theoretically possible for an electronic ignition if it had some "divide by 2" counters which could enable the circuits which process the Hall effect sensor signals only every other cycle. Possible, VERY complicated.

Right, because I can't tell from the crankshaft orientation or points alone which spark to choke.

Similar to the hall effect, however, I don't want to count on taking an initial potential or temperature reading to set my counter so it sounds like I'm going to have to identify valve orientation. Maybe a micro-points system based on the camshaft.........? Unless I'm ignoring a more obvious meathod.

Possible, but kinda complicated when the other spark is harmless.
Please note, although no boardcode and smiley buttons are shown, they are still useable

I would normally absolutely agree but in this case the waste spark is going to cause a fairly detrimental problem given what's going to be in the cylinder at the time.

Virii wrote:

Does anybody know of a coil per cylinder kit suitable for the kz650 or is this something that will take some creative engineering?

if you ran the bike using a megasquirt 2 kit you could use the expansion bay (prototype bay) to control individual coils and run the timing off a dyna s digital ignition or some other crank sensor you make yourself. i've thought of doing it myself but i can't build up the courage to spend 300 bucks for a kit and fuel railings and such.

Too bad the tach drive is not 1:1, could've used that.

what about one of the distributer systems run on the 1000 drag bikes? Do they still have a waste spark?

I've never worked with injectors so I just want to check the basics so I can follow this cool thread better.

The basics... at least as I know them:
1) 0° = Detonation Point.
2) 0° to 180° = Power Stroke (Cycle 1).
3) 180° to 360° = Exhaust Stroke (Cycle 2).
4) 360° = Wasted Spark
5) 360° to 540° = Fuel Intake Stroke (Cycle 3).
6) 540° to 720° = Compression Stoke (Cycle 4).
7) 720°= Detonation

OK, all the above manually/fixed advanced a few degrees early for performance and automatically/proportionally advanced a few more degrees as the RPM's increase (by the advancer for my vintage points ignition system, by the same advancer for newer Igniter systems and electronically for totally electronic systems).

If this still applies, I read that you want to start injecting fuel before 4) 360° = Wasted Spark... and therefore the need for four separate and independent ignition systems to accomplish this... right?

Thanks for everyone's patience... just trying to lean here.

Thinking out loud...
I guess you could treat each pair (1-3, 2-4) as separate circuits. The points, in my case, would fire the #1, a controller/Igniter would pass this on to #1 and not to #3, would start a timer until the #1 points signal again, this vale would be used to offset the #3 firing and multiplied by 2 to suppress the #1 waste as well as to single #1 and suppress the #1 Waste Spark. Of course, none of this will work unless you identify that #1 or #3 is at TDC on the first points closing... which you can’t do with only one set of points signalling #1 & #3. Unless... you had a manual button on your controller which said "Switch Cylinders". Your bike would fire correctly 50% of the time and you would have to push the Switch Cylinders or 180° button the other 50% of the time to get it started... hooked up to the Start button it could switch every time to tried to start again.

Repeat for 2-4.

Do-able... but you would not want all this complication and uncertainty. I guess that's where your cam position sensor would come in to solve this dilemma.

Please,don't quizz me on this... I would need to do a time/state diagram first to see if it even makes any sense.

This has been a good wake-up brain teaser.. almost as good as Sunday morning coffee... almost. Thanks.

Best of success!