Sounds like you should check the throttle linkage.
Sometimes, when you replace carb, think linkage can bind.
Go back over the repair with meticulous attention to detail.
Look at throttle plate and linkage while moving control from turtle to rabbit.
Just for general knowledge......
708cc Exmark engine:
How does the crankcase maintain pressure with the drain hose running up the side of the engine connected to the engine cover?
Does the drain hose act as a crankcase vent as well?
Generally, the oil drain is plugged with a bolt.
Thanks