The 4000 PSI @ 4 GPM Belt Drive Pressure Washer is a mount-ready commercial machine built on a Honda GX390 and a Comet RW4040S belt-drive pump. It's the high-pressure pick for concrete, stripping, and stuck-on grime. Choose pull or electric start.
Key Features
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4000 PSI pump rating: Built for high-pressure work where PSI does the cleaning, concrete, flatwork, and stuck-on grime.
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Honda GX390 engine: The 389cc, 11.7 HP commercial standard, with parts and service at any shop and Oil Alert low-oil shutdown.
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Comet RW4040S belt-drive triplex: Forged brass manifold, ceramic plungers, and stainless valves, backed by a 5-year pump warranty. Belt drive runs cooler and lasts longer than direct drive.
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Built-in protection: A thermal relief valve, a 50-mesh stainless inlet screen, and an external unloader with bypass guard the pump from heat, grit, and pressure spikes.
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Chemical injector included: A high-draw downstream injector ships in the box, so you can pull detergent without buying one separately.
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Mount-ready, pull or electric start: An aluminum skid with dual anti-vibration isolators bolts to a truck or trailer. Pick recoil or key start at checkout.
Belt Drive Pressure Washer Specifications
| Output pressure |
4000 PSI (pump rating) |
| Output flow |
4 GPM |
| Engine |
Honda GX390, 389cc, 11.7 HP net, with Oil Alert shutdown |
| Pump |
Comet RW4040S, belt-drive triplex |
| Pump build |
Forged brass manifold, ceramic plungers, stainless valves |
| Drive |
Belt drive, 3-groove belt with EZ-line tensioner and a two-piece aluminum belt guard |
| Start options |
Pull (recoil) or electric (key) |
| Frame |
Aluminum skid with dual anti-vibration isolators |
| Protection |
Thermal relief, 50-mesh stainless inlet filter, external unloader and bypass |
| Water type |
Cold water |
| Chemical compatibility |
Plain water through the pump. Apply chemical with the included downstream injector, then flush. No SH through the pump head. |
| Shipping weight |
144 lb |
What's Included
- The assembled pressure washer (Honda GX390 and Comet RW4040S on an aluminum skid, with an external unloader and bypass)
- 50' steel-braided non-marking gray high-pressure hose
- 36" spray wand with a molded grip and trigger gun
- 5 quick-connect spray nozzles
- High-draw downstream chemical injector
It mounts to a truck bed, trailer, or skid, and pairs with surface cleaners and 1/4" quick-connect accessories sized for 4 GPM. It's a cold-water machine. Run plain water through the pump and apply chemical with the included downstream injector, then flush. Don't run SH or other harsh chemical through the pump head.
How It Works
The Honda GX390 turns the Comet RW4040S through a 3-groove belt, stepping engine rpm down to the pump's working speed. The belt layout runs cooler and transmits less vibration than a direct couple, so the pump lasts longer under daily hours. Three ceramic plungers in the forged brass manifold build the pressure.
The external unloader routes water through a bypass loop the moment you release the trigger so pressure doesn't spike and blow a seal, and a thermal relief valve dumps water if the bypass loop overheats. A 50-mesh stainless inlet screen keeps grit out of the valves. For chemical, the included high-draw injector pulls detergent in downstream of the pump when you fit the soap nozzle. Run plain water through the pump and apply chemical downstream, then flush.
Pairs Well With
Frequently Asked Questions
Should I get the 4000 PSI 4 GPM or the 3000 PSI 5.5 GPM machine?
This 4040 trades flow for pressure, so it's the pick for concrete, stripping, and stuck-on grime where PSI does the work. The 3000 PSI 5.5 GPM machine trades pressure for flow and rinses faster across big surface area, which suits trucks, fleets, and wide flatwork. Match it to the work you run most.
Can I run SH or bleach through this pressure washer?
Not through the pump. SH corrodes the brass manifold and degrades the seals. Use the included high-draw downstream injector to pull chemical in after the pump, run the soap nozzle, then flush with clean water. Keep neat chemical out of the pump head.
Does it come with a chemical injector?
Yes. A high-draw downstream injector ships with it, so you can apply detergent out of the box. Pair it with soap-rated downstream nozzles and your chemical of choice.
