I jave a mansfield toilet that does not flush properly?

the mansfield toilet does not have a main flushing hole in the bottom of the toliet to help it flush. The bowl tends to fill with water before finally emptying. A 6' closet snake shows no blockage. 2 other mansfield toilets in the home have this 1" dia. hole in the base of the bowl and they flush immediately. Should I replace the toilet?