HighPressure Washer Pump 3400 PSI 2.5 GPM, SelfPriming Replacement Kit by | Jul 24, 2026Designed for 3/4” shaft engines with 180 to 225 cc (6.5 to 7 HP), it fits well with many gas pressure washer models. A thermal relief valve prevents overheating by releasing hot water and letting in cooler water.