MSefi.com read only forum (Jan.15,2018)

Hello, I am trying to get my trigger offset set but no matter what way I move from zero it doesn't change a thing. My mag pickup is set right at about 5 degrees BTDC. Sitting there running at idle its firing at 0 to 1 degrees BTDC, but I can not get the 8 to 10 that the computer is wanting no mater if I burn the trigger offset to 5 or -5 it doesn't change anything. The engine is a 2 cylinder motorcycle engine and idles roughly around 1300rpm. Is there another setting that I need to adjust for the MS to predict better. It will have to fire about 3 degrees before it gets its signal from the mag pickup. It is a MS-II V-3 board running code version 2.891

When I assembled the board I used the setup to control two LS1 coils using wasted spark per cylinder. Both coils fire at the same time every rev.. If that is any useful info..

I dug around in the manuals some more and found a section on trigger offset with some more info and an example. It showed that to change the timing by 2 degrees it took 10 degrees of offset. So I tried using bigger numbers and found that timing is moving as I change the offset. I'm still having trouble getting it set to match MS ignition adv., the big number. It will not advance any degrees before the mag. pickup sends its signal. So the most adv. I can get is about 5 degrees BTDC. I can move it in the other direction ATDC till the engine dies, but going any further than 5 BTDC it just stops and hangs up around 5 degrees and will not advance any further.

Lesson learned. ALWAYS REREAD AND DO THE MATH. I dug deeper in the manuals and was wondering just what the burn time of the gasses in the cylinder were doing. Surprisingly, if 17 degrees ATDC is optimal peak pressure then for my engine at a bore size of 2.95in. with the plug located offset 2in. to one side, the burn time is 2.2 milliseconds at 1,300rpm. Which put in the formula equals 17.16 degrees traveled till burn is complete. When you minus the 17 degrees until peak pressure I get: .16 degrees BTDC advance timing. I'm so used to bigger V-8s that I tried to use the same logic, doesn't work. Once I started to use the bigger numbers for trigger offset I noticed that the reason I couldn't advance any more than 5 degrees BTDC was because it was running so rough that it would die, should have set a light bulb off in my head, but because I just knew that the advance should be higher, it never did. I did notice that the closer I got to 0 degree TDC the engine did run smoother and I though I had screwed up on marking the degrees on my crank hub, which I rechecked to make sure that was not the case. Once I went back and did some more reading it became apparent what was going on inside the engine. So with that in mind, I have an entire spark map to recalculate, USING THE FORMULAS. Thank you so much Bowling and Grippo and all independents for all the info and time that has been put into this.