I just had a forced landing gear extraction due to a deadstick...the engine runs fine for 5 flights and on the last one right after takeoff its sputtered and died...you know the rest of the story!
upwind and 40' altitude at the end of runway... not much to do except pulling back to flare and hope for the best.

is there a way to know for sure if the plug is worn out or any other indication ?

my engine is a Saito fa125 with O.S ''F'' type plug, Cool power 30%