This is the parts needed to replace on the HS1000-2 model (Utility w/dump bed).
Many of these parts are the same for the 1000-1, 1000-3 (Sport Model with Bucket Seats)
This is the HiSun Factory Piston Kit for the 450 Engine. It has a Bore of 83mm and a Stroke of 84mm = 454cc.
Similar to the HiSun 500 but the 450 uses a 19mm Wrist Pin, 500 = 20mm. The Crank Rod is Different.