Setting the ignition curve with a Sachse ZDG 3.12

[Jacks the Lad]

My 350cc Scrambler is fitted with a Saches ZD 3.12 electronic ignition which has 9 different curves. Which one would be most suitable? Has anyone got one and which one did you choose?

Not looking to "tune-up" or go racing, just the bog standard set-up would be fine.
Also there is a certain amount of "kick-back" when starting which makes me wonder if the pick-ups are set correctly in the first place.

[themoudie]

Aye John,

I assume from your post that you already have downloaded a copy of the pdf installation manual?

Link: manuals/Z19-D-3.12-en

Maximum advance for a 350 motor is between 33 degrees and 36 degrees, Before Top Dead Centre (BTDC) @ 3,000rpm.

Therefore, it would appear from the Sachse advance curve diagram that either advance curve 4 (yellow) or 5 (lime green) would be suitable for maximum advance. What difference the more rapid rise to full advance, curve 5 (lime green) makes to the tractability of the engine, when compared against the slower rise to full advance of curve 4 (yellow), I am not able to say. I could guess, but that is of no help.

I would advise that you drop an email directly to Nigel Lacey to find out if he has a preference for the road going motor from experience, as he sells these ignition systems.

My regards, Bill

[Jordan]

I don't know about Sasche, but another elec ignition box I've used would not provide any retard at low battery voltage, which caused kick-back.

Graphs here show all curves with no advance until 1000 rpm, so none should be likely cause of kickback, if timed correctly?

I have some old bikes with manual advance and retard, from which I've learned that timing isn't really so sensitive, apart from at start/idle and full advance. They are not race bikes.