Petrol Flood & Site Pump Kit | Honda WB20 - 2 Inch
Built for the job
Petrol flood and site pump kit for dewatering, farms and flood response
The 2 inch pump everyone else already owns, supplied with the hoses that make it work.
This FPS Engineered™ kit pairs the Honda WB20 with 6m of 50mm reinforced suction and delivery hose and 30m of 50mm layflat for the discharge. The pump supplies its own couplings, washers, clips and strainer, so the kit completes it.
The WB20 is the industry standard for a reason. A commercial-grade Honda GX120 4-stroke driving an abrasion-resistant cast iron volute and impeller, with a silicon carbide mechanical seal keeping water away from the engine, all mounted on anti-vibration rubber in a tubular steel crash frame. It moves up to 620 litres per minute and lifts 32 metres, and it turns up on hire fleets and in utility vans because it keeps going.
Part of our wider engine driven pump, Honda and flood defence ranges.
Why a surface pump needs two different hoses
A submersible sits in the water. A petrol pump sits on the bank, and has to pull the water up to itself first.
That changes what the hose on the intake has to do. As the pump draws, pressure inside the suction hose drops below atmospheric and an ordinary hose flattens shut. Reinforced suction and delivery hose has a helix moulded into the wall that holds it open against that vacuum. Layflat on the suction side simply will not work: the pump pulls it flat and loses prime.
On the discharge side the hose is under pressure, which holds it open by itself. That is where layflat belongs: lighter, cheaper per metre, and it rolls down to a fraction of the space for transport.
Six metres of reinforced on the suction, thirty metres of layflat on the delivery. That is enough suction hose to reach down a bank or into a chamber, and enough delivery to get the water genuinely clear of the site.
At a glance
- 474 litres per minute through the kit: Around 28,000 litres an hour at a typical 2m lift.
- Both hoses supplied: 6m reinforced for suction, 30m layflat for delivery.
- Cast iron volute and impeller: Abrasion resistant, for site water carrying silt and sand.
- Silicon carbide mechanical seal: Keeps water away from the engine, which is what kills cheaper pumps.
- Honda GX120 with Oil Alert: Shuts the engine down if oil runs low, in a tubular steel crash frame on anti-vibration mounts.
What's included
- 1 × Honda WB20 petrol water pump, with hose couplings, washers, clips and suction strainer
- 1 × 6m length of 50mm reinforced suction and delivery hose
- 1 × 30m length of 50mm layflat delivery hose
Petrol and oil are not included. The GX120 runs on straight unleaded with no mixing, and has a 3.6 litre fuel tank.
How the kit connects, and how to prime it
Both ports on the WB20 are 50mm, 2 inch. The reinforced hose goes on the suction side with the strainer fitted to the far end, and the layflat goes on the discharge. Secure each with the clips supplied with the pump.
Fit the strainer every time. It comes with the pump and it is not optional. The WB20 passes 6 mm solids, and the strainer is what stops anything larger reaching a cast iron impeller.
Prime before starting. The WB20 is a self-priming centrifugal pump, but self-priming means it will clear air from the suction line once the casing is wet, not that it starts dry. Fill the pump casing with water through the priming plug until full, then start the engine. Running dry destroys the mechanical seal.
Keep the suction lift as short as you can and the suction hose as straight as you can. Priming takes longer the higher the pump sits above the water, and every bend on the intake side costs you more than one on the discharge.
Expected performance
Estimated flow through the full 36m of 50mm hose supplied. Total lift is the suction lift plus the delivery lift added together, measured from the water surface to the point where the hose discharges.
| Total lift | Typical situation | Estimated flow | Per hour |
|---|---|---|---|
| 2 m | Flooded yard or field, ground level discharge | Approx. 474 L/min | Approx. 28,400 litres |
| 5 m | Ditch or excavation up to a road drain | Approx. 449 L/min | Approx. 26,900 litres |
| 10 m | Up a bank, or filling a raised tank | Approx. 404 L/min | Approx. 24,300 litres |
| 15 m | Steep ground or high storage | Approx. 354 L/min | Approx. 21,200 litres |
| 20 m | Serious elevation, still working well | Approx. 296 L/min | Approx. 17,800 litres |
Estimated using the published WB20 curve and Hazen-Williams friction for 50 mm bore across the full 36 m of hose supplied. At 449 litres per minute a 1,000 litre IBC empties in about two minutes, 10,000 litres in around twenty, and a flooded 60 m² room with 200 mm of water in it in under half an hour. Work out a specific run with our pump performance calculator.
A note on the 30 metres of layflat. On our smaller 50 mm kits, hose length is almost free, because at 200 or so litres per minute friction is negligible. At 620 litres per minute it is not: friction rises steeply with flow, so on this pump the full 36m run costs around 14 percent against a short one. That is a price worth paying for reach on a flood or site job, but if your discharge point is close, use less hose and you will move more water.
Petrol engine safety
Never run a petrol pump indoors or in any enclosed space.
Petrol engines produce carbon monoxide, which is colourless, odourless and lethal. That rules out cellars, basements, garages with the door shut, containers, tents and covered walkways, even briefly and even with a window open. If the water is inside a building, put the pump outside and run the suction hose in, or use an electric submersible instead.
Stop the engine and let it cool before refuelling, keep petrol away from the hot exhaust, and site the pump on firm level ground. The anti-vibration mounts stop it walking or burying itself in soft ground, but it still needs a stable base.
Technical specification
| Specification | Honda WB20 |
|---|---|
| Pump type | Petrol engine driven self-priming centrifugal surface pump |
| Maximum flow | 620 litres per minute |
| Maximum total head | 32 metres |
| Inlet and outlet | 50 mm, 2 inch, both ports |
| Free passage | 6 mm |
| Engine | Honda GX120, OHV 4-stroke, with Oil Alert |
| Power | 4 hp |
| Fuel tank | 3.6 litres |
| Volute and impeller | Abrasion-resistant cast iron |
| Seal | Silicon carbide mechanical seal |
| Frame | Tubular steel crash frame on anti-vibration mounts |
| Dimensions | 365 × 455 × 420 mm |
| Dry weight | 21 kg |
| Part number (MPN) | WB20 |
| Warranty | 1 year |
Which Honda pump kit?
All three are Honda 4-stroke petrol pumps. Choose by how much water you need to move.
| Kit | Ports | Flow and head | Weight | Choose it when |
|---|---|---|---|---|
| WX10 Transfer | 1 inch | 140 L/min, 36 m | 6.1 kg | Portability and height matter more than volume |
| WB20 Flood & Site | 2 inch | 620 L/min, 32 m | 21 kg | The general-purpose standard for site, farm and flood |
| WB30 High-Flow | 3 inch | 1,100 L/min, 28 m | 26 kg | Maximum volume for large dewatering and flood |
The WB20 is the one to buy if you are not sure. It moves four and a half times what the WX10 does for five extra kilos of hose and pump, and it is the size hire fleets and utilities standardise on. Step up to the WB30 only when the sheer volume of water is the constraint rather than the lift.
What can I use it for?
- Site and construction dewatering, excavations, ditches and footings
- Emergency flood water removal from yards, fields, car parks and access roads
- Agricultural irrigation and water transfer
- Livestock and yard washdown water management
- Emptying tanks, ponds, lagoons and large containers
- Estate, smallholding and equestrian use
- Hire fleet stock, where one pump has to cover several kinds of job
Water quality limits
Clean and slightly muddy water, solids to 6 mm. The cast iron volute and impeller are specified to resist abrasive silt and sand, which is why this pump lasts on site, but always fit the supplied strainer. It is not a trash or sewage pump, and not for foul water or salt water. It does not treat or filter water, so nothing it moves is drinking water.
Frequently asked questions
Why do I need this kit if the pump is sold on its own?
Because the pump is supplied without hoses, and a surface pump cannot do anything without them. It needs a reinforced suction hose that will not collapse under vacuum and a delivery hose on the other side. This kit supplies both, correctly sized in 50mm to match the ports.
Why are the two hoses different?
The suction hose works under vacuum, so it must be reinforced or the pump will pull it flat and lose prime. The delivery hose works under pressure, which holds it open, so layflat is fine there and it is lighter and packs down far smaller.
Can I use layflat on the suction side?
No. It will collapse as soon as the pump draws and the pump will not prime. Reinforced on the suction, layflat on the delivery.
Does self-priming mean I do not have to prime it?
No. Self-priming means the pump can clear air out of the suction line once its casing is wet. You still have to fill the casing with water through the priming plug before the first start, and running it dry destroys the mechanical seal.
Can I run it in a cellar or a garage?
No. Petrol engines produce carbon monoxide, which is lethal in an enclosed space. Site the pump outdoors and run the suction hose in, or use an electric submersible pump instead.
Is a strainer included?
Yes, with the pump, along with hose couplings, washers and clips. Fit it every time: it is what keeps anything larger than 6mm away from a cast iron impeller.
Should I buy the WB20 or the WB30?
The WB20 unless volume is your specific constraint. It handles the great majority of site, farm and flood work, weighs five kilos less, and actually has more head than the WB30. The WB30 is for when you need to move the maximum amount of water and the lift is modest.
Will 30 metres of layflat slow it down?
A little. At this flow rate the full run costs around 14 percent against a short one, because friction rises steeply with flow. It is worth it for the reach on a flood or site job, but if your discharge point is close, use less hose and you will move more water.
Does it need two-stroke fuel?
No. The GX120 is a 4-stroke, so it runs on straight unleaded with oil in a separate sump. It also has Oil Alert, which shuts the engine down if the oil level drops.
Full spec sheet
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