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trigger offset

Posted: Fri Jun 09, 2006 7:49 am
by Ludotech
hello everybody,

I found another problem today with my MS II and EDIS :

My trigger offset in Megatune is 20 ° but my advance measured with a timing light is 10 °.
So, when I try to match the two numbers, the number displayed in Mt (trigger wizard) decreases to, for example 17° but my advance displayed by the timing light decreases too and the engine stops because the ignition advance is less than 5°c...

Am I missing something???????

nb: my limp home mode is just 10°c, so my trigger wheel is mounted correctly, I don't understand.

If someone could help me, It would be great.

Thanks.

Ludovic

Posted: Fri Jun 09, 2006 7:52 am
by jsmcortina
Do you have the code set to EDIS mode ?

James

Posted: Fri Jun 09, 2006 7:54 am
by Ludotech
i followed the informations in the EDIS section of MS II so i think that it's OK:

* Trigger offset = 10° (this will vary, depending on the wheel/pickup configuration),
* Ignition Input Capture to 'Falling Edge',
* Cranking Trigger to 'Trigger Return',
* Coil Charging Scheme to 'EDIS',
* Spark Output to 'Going High (Inverted)'.

Posted: Sat Jun 10, 2006 2:00 am
by Ludotech
Nobody can helps me?
This problem seems very weird to me: When i decrease the big number, does this normally influence the real ignition advance seen by the timing light?
If yes, I will never be able to match the number displayed by the timing light.

So: when I decrease the big number to match the timing light, the ignition advance seen by the timing light shouldn't decrease, Am I right?

Thanks for trying to help me.

Ludovic

Posted: Sat Jun 10, 2006 6:47 am
by Bernard Fife
Ludotech,

Are you using a dial-back timing light? If so, you MUST use it only at the base setting and use the timing marks to determine timing. This is because the timing light needs to calculate the engine rpm to determine how to do the 'dial-back' and it does this based on the frequency of the spraks. But a wasted spark system, like EDIS, has twice the spark frequency, which mess up the timing light`s calculations.

So with EDIS, the best be is to disconnect SAW signal, and set the timing to 10° BTDC, set the timing offset to 10°, then verify that that the timing in Megatune matches the timing with the timing light - using the timing marks not the dial-back fearture.

Lance.

Posted: Sun Jun 11, 2006 2:44 am
by Ludotech
lance,

i don't know what you mean by a dial-back timing light(my english isn't perfect): I'm using a timing light that indicates the advance, rpm, and the DWELL.
I have only connected the inductive clamp to the spark plug wire from the cylinder 1. I know that the frequency of the spark is twice bigger but i have selected a two stroke engine on the timing light.
So with EDIS, the best be is to disconnect SAW signal, and set the timing to 10° BTDC, set the timing offset to 10°, then verify that that the timing in Megatune matches the timing with the timing light - using the timing marks not the dial-back fearture.
Ok, i'll do this.

Thank you very much.

Ludovic

Posted: Sun Jun 11, 2006 8:32 am
by S.Bretz
Get a cheap timing light that won't tell you dwell and timing advance. YOu want one with just a trigger on it. I had the same problem.


An easy way to go about this it to set all you timing advance numbers to a certain number on the entire map...say 0 degrees.YOu will have to give it more gas as the lack of timing advance will make the engine run poorly. Get the Cheapt timing light ready and start timgin it. Adjust the crank offset until you get the TDC on the crank pull to TDC on the timing cover. Then you are dialed in and ready to go.

Posted: Mon Jun 12, 2006 4:57 am
by grippo
Ludotech wrote:i followed the informations in the EDIS section of MS II so i think that it's OK:

* Trigger offset = 10° (this will vary, depending on the wheel/pickup configuration),
* Ignition Input Capture to 'Falling Edge',
* Cranking Trigger to 'Trigger Return',
* Coil Charging Scheme to 'EDIS',
* Spark Output to 'Going High (Inverted)'.
You don't want any cranking trigger - EDIS takes care of that for you.