On my DA50, the load on battery is around 600ma when the throttle is fully advanced, and the static current drawn is about 25ma. What is the max current drawn for the fuji engine and is 300ma sufficient?

If ig. module goes bad, the engine will not start at all. The sensor wire on my DA50 did broken once and when that happens, there is no spark as well.

Switch can go bad or becomes intermittent once in while. Is the switch heavy-duty kind, and mounted away from the engine?

Finally, have you ruled out lean run situation? How many minutes into the fly will the engine usually quit? Will the plane slow down when pull into a verticle line, or it always quits shortly after the throttle is advanced? If so, then the engine is lean.

The othher possible source of lean is air leak.