How does the ATV crank? It might be a low voltage problem, use a multimeter and see what your battery is putting out.
Mine cranked up fine too, but had the same symptoms yours does, turns out it was the battery. I had to replace it, it wouldn't even hold a charge from a battery charger.Everything seems fine. I'll have to check and see. If I can find my voltmeter. But it cranks fine and everything else seems fine.
Clark