Summary of the project this far.
I've struggled (still struggling bit) with sync loss due to ignition noise affecting speeduino - still working on that.
I worked out that my old Kettering style coils wont work well with programmable dwell (too higher resistance/low current) so bought some 0.5 ohm Dynatek ones (thanks lav1000).
They work very well with the Bosch 211 clone trigger and I found a good dwell calculator to run the calcs for dwell and duration of spark.
This helped me set up the basic starter numbers and adjust the compensation curve. The dynateks are optomised at around 13.5v which gives a dwell of 2.8ms, so for now I have made that 100% on the curve but might adjust it when I now the normal battery running voltage.
I've set spark at an average of 2.2ms from the program.
So ignition side is done once I finish the noise issue. Speedy can handle a 2 stroke, 3 cylinder 750cc engine