SIMPSON AAA AX300 Axial Cam Pump Kit 90052
3,500 PSI · 2.5 GPM · 3/4 in shaft.
The SIMPSON 90052 is a replacement AAA AX300 axial cam pump kit rated 3,500 PSI at 2.5 GPM, for engines with a 3/4 in horizontal shaft. It has a garden-hose inlet and a threaded M22 outlet, and fits engines such as the Honda GC190 and GX200.
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Specifications at a glance
| Brand | SIMPSON |
|---|---|
| Part number | 90052 |
| Pump | AAA AX300 axial cam |
| Engine shaft orientation | horizontal |
| Shaft diameter | 3/4 in |
| Max pressure | 3,500 PSI |
| Max flow | 2.5 GPM |
| Inlet | Garden hose |
| High-pressure outlet | threaded M22 |
| Manifold | brass |
| Unloader | integrated and adjustable, with Easy Start |
| Warranty | 3-year |
From SIMPSON's pump catalog. Anything SIMPSON doesn't state is marked as not stated.
What to know about the 90052
Shaft and orientation
The pump slides onto the engine crankshaft, so the shaft must be 3/4 in and horizontal. SIMPSON names the Honda GC190 and GX200 as 3/4 in shaft engines.
Match the rating
SIMPSON's guidance is to match engine orientation, PSI, GPM, shaft diameter and the inlet and outlet connections of your current pump. This kit is rated 3,500 PSI at 2.5 GPM; after any pump change, size your nozzles to the new rating with the nozzle size calculator.
Outlet and hose
The outlet is threaded M22, so it takes the M22 hoses most homeowner gas washers use, such as MorFlex.
Key features (from SIMPSON)
- AAA AX300 axial cam pump
- 3,500 PSI at 2.5 GPM
- 3/4 in shaft, horizontal engines
- Brass manifold
- Unloader: integrated and adjustable, with Easy Start
- Garden-hose inlet, threaded M22 outlet
- 3-year warranty
Is it right for you?
| Good choice if | your engine has a 3/4 in horizontal shaft and your washer was rated close to 3,500 PSI at 2.5 GPM |
|---|---|
| Look elsewhere if | your engine shaft is not 3/4 in |
| Look elsewhere if | your engine is vertical-shaft |
| Look elsewhere if | your hose uses quick-connect fittings and you don't want adapters |
Questions about the 90052
Will the SIMPSON 90052 fit my pressure washer?
It fits engines with a 3/4 in horizontal shaft and the standard SAE bolt pattern, on washers rated around 3,500 PSI at 2.5 GPM. Check your engine shaft and your current pump's inlet and outlet first.
Do I need new nozzles after changing the pump?
Only if the new pump's rating differs from the old one. Work out the right size for 3,500 PSI at 2.5 GPM with the nozzle size calculator.
Does the 90052 need oil?
Axial cam pumps like this are usually sealed; check the manual for your kit.
What to check before buying
Other 3/4 in shaft pump kits
- SIMPSON 90036 3,200 PSI · 2.8 GPM · AAA Triplex
- SIMPSON 90029 3,300 PSI · 2.4 GPM · OEM Technologies Axial Cam
- SIMPSON 90037 3,700 PSI · 2.5 GPM · AAA Triplex
Source and editorial status
Manufacturer reference: SIMPSON pump catalog ↗. Specifications checked 3 November 2026. We have not tested this product.