If your walk behind mower is hard to push, please check the following items:
1. Grass is to high or wheels are set to low. Adjust cutting height.
2. Rear of lawnmower housing or cutting blade dragging in the grass. Raise rear of lawnmower housing by adjusting the rear deck height adjusters one setting higher.
3. Grass catcher too full. Empty grass catcher
4. Handlebar height position not right for operator. Adjust handle height to suit operator.
If you have checked the above please contact the dealer you purchased the machine from or your local Ariens dealer.
Please see link below: