The Stonechat is designed for additional weight so that you can complete your job in less time.
Simply add 40lb horseshoe weights (one at a time) and monitor the on-board amperage meter to ensure you are not overloading the circuits. As long as you are operating within the “safe” limits you can add more weight to the machine.
The Stonechat accommodates up to ten 40lb horseshoe weights for a maximum of 400 lbs (181 kg) of additional weight.