W4443W 4400 PSI Universal Gas Engine Pump Bypass

W4443W | Bertolini 4400 PSI 4.3 GPM Pump with Built-In Unloader and Injector, GX390

W4443W is the Bertolini WMG-W version of the W4443, rated 4.3 GPM at 4,400 PSI at 3450 RPM, with the unloader and an adjustable chemical injector built into the pump head. There is no separate unloader to plumb and no bypass hose to route: bolt it to a GX390-class engine, connect your hose, and run.

Why 4,400 PSI, and why only here: Bertolini’s standard WMG is rated 4,000 PSI. This pump is built with stronger side bearings and upgraded bronze connecting rods, and Bertolini has granted it a 4,400 PSI rating exclusive to WSHPWR.com. It is made in Reggio Emilia, Italy, where Bertolini has built pumps since 1918.

Why a Built-In Unloader

Because the W4443W unloader is machined into the forged brass head rather than bolted to the outlet, there are fewer fittings to leak, nothing to snag on the frame, and nothing to line up when you swap pumps. Turn the knob to set working pressure from low up to the full 4,400 PSI, and dial the injector to set your detergent ratio.

Which W4443 Do You Need?

All versions use the same 4,400 PSI pump. Choose the one built for your machine:

• Bare pump: no unloader. For shops that reuse their own unloader and plumbing.
• W (this page), WS and WP versions: built-in unloader and injector, with standard, socket quick connect or Pressure Pro outlet.
• VRT, VP and VPI versions: plumbed with a VRT unloader, Pressure Pro plug, and an injector on the VPI.
• T, WT, WST, WPT, VRTT and PIT versions: tank and gravity feed versions for trailers and skids.
• H, WH, HT and WHT versions: hot water versions with high-temperature seals.

What’s in the Box

• W4443W pump with built-in unloader and adjustable chemical injector, fully assembled
• SAE J609 1 in. flange mounting bolts and lock washers
• Crankcase filled with Bertolini’s SynPower 75W-90 break-in oil
• Vented dipstick. Install it before the first start. Never run the pump without it.
• 7-year Bertolini warranty

Will It Fit My Machine?

It is a direct replacement for the pump on:

• Simpson SuperPro Roll-Cage SRC4440112
• BE Power Equipment B4415PCS
• Pressure-Pro E4040HA, E4042HV and SLPVV4G42-400
• Machines running Annovi Reverberi RKV4G36, RKV4G40 or RRV4G40 pumps

It fits any direct-drive pressure washer with a 1 in. horizontal engine shaft and SAE J609 mounting face, on a 389cc to 420cc engine (GX390 class). Ports are BSP, so plan BSP fittings or adapters on NPT plumbing.

Not sure the W4443W fits? Text a pump specialist at (505) 226-6061 with a photo of your machine’s tag and we’ll confirm.

What Makes a Bertolini Different

• LowStressthread valve caps: the O-ring seals ahead of the thread, so pressure water never reaches it. The caps don’t loosen, need 40% less torque and put 60% less stress on the head.
• Lifetime oil: change the break-in oil once at 50 to 100 hours to standard 75W-90 gear oil, and that fill lasts the life of the pump.
• Built heavy: thick forged brass head, AISI 316 stainless check valves, solid ceramic plungers on nitrided stainless plunger rods, one-piece bronze connecting rods, oversized bearings and an extended forged steel crankshaft.

Common Questions

• Do I need a separate unloader? No. On the W4443W it is built into the pump head.
• How do I pull soap? Switch to a low-pressure soap nozzle. The injector draws detergent at low pressure, and its dial sets the ratio.
• Can it run hot water? The W4443W is rated to 140°F. For hotter water, choose an H version.

W4443W Specifications

• Model: W4443W (Bertolini WMG-W series)
• Flow: 4.3 GPM at 3450 RPM
• Max Pressure: 4,400 PSI (WSHPWR exclusive rating)
• Unloader: Built in, adjustable
• Injector: Built in, adjustable
• Shaft: 1 in. hollow
• Mount: SAE J609 1 in.
• Engine: 389cc to 420cc, GX390 class
• Plungers: Solid ceramic, 15 mm
• Connecting Rods: Bronze, one-piece
• Check Valves: AISI 316 stainless steel
• Oil: 0.6 L SAE 75W-90
• Max Water Temperature: 140°F
• Weight: 17 lbs
• Warranty: 7 years
• Brand: Bertolini, made in Italy

Shipping: Usually ships via UPS in 1 to 3 days.