Dead Eye Dick

My ZDZ 50NG has run flawlessly for a couple of years and then today had a perfect flight without any problems and on the second flight she suddenly stopped throttling up and one could hear the engine barking, bang bang bang but ticked over sweat as ever when I reduced throttle. She wouldn't open up again. I was lucky to land on idle.

Checked everything, nothing loose, sensor and plug looked fine, throttle servo operating correctly. Restarted and she ran as sweet usual, as nothing was wrong. A perfect tick over and throttled up several times OK in the pits. Never missed a beat. Taxied out to take off, pre throttle up check and bang bang bang, no pick up. It sounded like ignition. She would run flawslessly on idle but refused to throttle up without barking bang bang bang and no pick up on revs. Suggestions welcome?

Dead Eye Dick

OK found the source of my problems .... ignition battery was on the way out. Voltage had dropped right off. Replaced with a new battery and all OK.