4400 PSI Pressure Washer Pump Power Washer Pump 1" Shaft Horizontal 4 GPM Wide Compatibility: Designed with a standard SAE bolt pattern, our parts washer pump is compatible with various gas pressure washers with horizontal engines, including Simpson MorFlex models 40224, 40225, 40226, and Santoprene model 41182. To ensure compatibility, be sure to match engine orientation, PSI, GPM, engine shaft diameter, and current pump inlet and outlet connection. .