Yale GLP060VXEUSE087, 9700 hours
Ran ok, with intermittent loping idle and code 522655-1 when warm.
Then just stopped. Cleaned the small fuel filter, was full of goo. Checked the filter on the regulator, perfect. Checked spark, it's sparking but yellowish and not strong. Checked timing, hard to tell exactly but appears to be around 4 degrees before TDC on the marks. Swapped in a new coil and ignition module, no change. Sprayed ether into it, zero. Checked compression: 120, 170, 160, 160. Checked the ignition fuses, all ok. Plugs, cap, rotor and O2 sensor were replaced like 30 hours back, plugs are perfect, cap and rotor are good, wires look fine.

So with decent compression I don't think the cam belt skipped a tooth. Should have started or at least tried on ether even if the propane regulator or carb wasn't working. All I can think of is spark.

Ideas?

Besides the coil and ignition module (Mazda parts), there is what appears to be a power transistor on that bracket, but can't find a part number. Anything else in that circuit?

Thanks!