mdegreve

Thanks for this information. I just checked the timing and it was OK. I ordered a new ignition today.
It's a pity that the Zenoah stock ignition is not reliable. The engine has only 40 flights.
Sometimes, every 10-15 flips or so the engine pops, but won't start.
Indeed, looks like an ignition problem and more than probably, it happened in flight.
I will keep posting news about the results when the new ignition will arrive.