technical ignition, pulse generator question

[Jeram]

to cut straight to the chase,

why does the CRM AR have 6 ignition pickup points on the flywheel?


and why does the AR have two pulse generators instead of 1.
All I can find is that at TDC, 2 of the points line up with the pulse generators.
other than that, I am completely baffled.


my issue is, for my aftermarket ignition to work, I need to have just 1 pickup point and 1 pulse generator that trigger at TDC.
so I need to work out which 5 points to grind off and which pulse generator to keep

pics for reference.

wiring diagram pic
http://www.supermotoaus.com/picture.php ... tureid=724

my 6 pickup points and 2 pulse generators painted white
http://i70.photobucket.com/albums/i92/S ... 010015.jpg

I think Im going to keep the point that contacts with the RHS pulse generator at TDC, and will keep the RHS pulse generator.

[Jeram]

ok, so Iv found a bar that triggers just a few degrees BEFORE TDC at the Right hand side pulse generator.
This may be the one I want, Iv sent the question to Two Stroke Institute.

(crank position just before TDC)
http://i70.photobucket.com/albums/i92/S ... 010018.jpg
(bar/trigger just before TDC)
http://i70.photobucket.com/albums/i92/S ... 010017.jpg

[Jeram]

ok so Iv worked this damn thing out I think.

when both pulse generators get a pulse at the same time the ECU knows that its top dead center. then depending on what the revs are the bike will switch between the front and back pulse generators.

and depending on the revs the ECU will count the pulses, for instances at 5000RPM the ECU might switch to the front pulse generator, and then count 3 pulses after TDC (when both pulse generators pulse), on this 3rd pulse it sparks.

but increase the revs more and it might switch back to the back pulse generator and pulse on the 2nd pulse after TDC.

essential its an Old skool way of controlling ignition timming before proper acurate ecu's came about :)

[ittakir]

here is the map of pulses:
http://lh4.ggpht.com/_jXsAEWBbiiM/S2LJm ... ignmap.PNG

I don't know, why they made it so complicated. Maybe because of active radical system - to be able to measure acceleration of the flywheel (and so to know current compression ratio, etc.).

[Jeram]

thanks!!!!!!!!!!!!!!!!!!!!!