My motor will not idle without cutting off.When it cutts off it has a hard jerk.And a soft backfire almost like backpressure.Also when ran with throttle pushed forward slightly it will run but tends to still jerk as if it is about to cut off.runs fine at wot.also to get it to go in gear without cutting out you have to push into gear very fast.Or it will die.I tried new coils,new plugs,and checked the fuel filter and carbs for debris.Any advice would be greatly appreciated thanks
