Dart not restarting .

My 74 did the same.lol
Junk in the tank, kept changing filters too.
But I think it was carb related. 'Flooded after shut down' leaky needle n seat in the carter.
I changed the carb and it fixed it .Try the wot trick. I usually had to remove the air cleaner and blow air down the carb.
Something that occurred with those years.