John, while it's not "Big Bore", I am at about 13.2:1 compression.
I'm using the XDI/2 set-up, and I've been told to take heed of the smaller gaps recommended by Electromotive - .022".
Of course, the gap between the sensor and the wheel are also critical.
Peter Jacks suggestion is precisely how I start mine.
If you aren't already using one, I might suggest a gear reduction starter - it will crank the engine over more uniformly.
Once I had mine dialed in, it was flawless, with the exception of not being able to properly record my dyno sessions. I suspect it's a software issue.