How does a portable water pump work?

An engine spins an impeller that pulls water up the suction hose and pushes it out the discharge hose once the pump case is primed with water.

How do you prime a portable water pump?

Fill the pump case through the priming port before starting; Honda lists 80 to 110 seconds to prime at a 16.4 ft lift.

How high can a portable pump lift water?

Honda's WX10 and WB20 list about 25 to 26 ft of suction lift and over 100 ft of total head.

Can I run a gas water pump in a garage or basement?

No; engines make carbon monoxide, so run them outdoors only.

Home / Water

Portable water pump: match the port size to the job

By the Plain Prepper editors. Updated 2026-10-15.

We research products from makers' specs, manuals and safety agencies; we do not run hands-on tests. Links to Amazon may earn us a commission at no cost to you. How this works.

Quick answer

A portable gas water pump moves water from a pond, flooded yard, pool or tank through a hose. Port size sets the flow: Honda lists 32 gallons per minute for its 1 inch WX10 and 164 for its 2 inch WB20. Both lift water about 25 to 26 feet on the suction side, so keep the pump close to the water. They are self-priming once you fill the pump case, and like any engine they must run outdoors because of carbon monoxide.

1 inch vs 2 inch pumps

Spec	Honda WX10 (1 in)	Honda WB20 (2 in)
Flow	32 gal/min	164 gal/min
Suction head lift	26 ft	25 ft
Total head lift	121 ft	105 ft
Maximum pressure	52 psi	45 psi
Priming time	80 s at 16.4 ft	110 s at 16.4 ft
Run time at max flow	0.9 h	1.7 h
Weight	13 lb	44 lb
Engine	GX25, 25 cc	GX120, 118 cc
Residential warranty	2 years	24 months

All figures are Honda's specifications. The WB20 moves about 5 times the water per minute of the WX10.

Flow, lift and pressure in plain terms

Gallons per minute: how fast water moves at its best; at 164 gal/min the WB20 could move about 9,840 gallons in an hour, and the WX10 about 1,920.
Suction head lift: how far below the pump the water can be; both Honda pumps list about 25 to 26 feet, so set the pump near the water's edge.
Total head lift: how high the pump can push water in total; flow drops as you push higher or farther.
Pressure: the WX10 lists 52 psi and ships with a garden hose adaptor; the WB20 lists 45 psi but far more volume.

What each pump is for

WX10: Honda pitches it for homeowners, gardeners and boat owners, includes a garden hose adaptor, suction hose, clamps and strainer, and weighs 13 lb.
WB20: a general purpose 2 inch pump for draining larger volumes, with a cast iron volute and 4-vane impeller and a silicon carbide seal Honda says resists abrasion.
Solids: Honda says the WB20 strainer lets particles up to 8 mm (5/16 inch) pass to help prevent clogging; neither is a trash pump for mud and debris.
Fuel per tank: at full flow the WX10 can move about 1,700 gallons per tank and the WB20 about 16,700, by multiplying flow by Honda's run times.

How long will the job take?

A worked example: moving 10,000 gallons, an example volume, at each pump's rated maximum flow.

WB20 at 164 gal/min: about 61 minutes, within one tank at Honda's 1.7 hour run time.
WX10 at 32 gal/min: about 313 minutes, or 5.2 hours, roughly six tanks at 0.9 hours each.
Real jobs run slower: rated flow is a maximum; lifting water higher, pushing it farther through long hoses, or a clogged strainer all cut the gallons per minute.

For big volumes, the 2 inch pump saves hours and refuels; for watering a garden or emptying a pool cover, the 1 inch pump's light weight matters more.

Priming and setup

Place the pump on firm, level ground outdoors, as close to the water as you can.
Fit the strainer on the suction hose and keep it off the bottom so it pulls clean water.
Prime: fill the pump case with water through the priming port before starting; Honda lists priming times of 80 to 110 seconds at a 16.4 ft lift.
Start and watch: check that water flows and that the discharge hose is laid where the water can drain away from buildings.
Shut down before the source runs dry, and drain the pump case in freezing weather.

Follow the owner's manual for oil, fuel and priming specifics.

Safety: engines outdoors only

Carbon monoxide: CPSC calls CO a colorless, odorless poison and warns never to run engine generators inside homes or garages, even with doors open; the same engine exhaust hazard applies to engine-driven pumps.
Flood water: treat it as dirty; wear gloves and wash up after handling hoses and strainers.
Fuel: refuel only when the engine is off and cool, away from the water source.
Drinking water: a transfer pump is not a filter; treat any water you plan to drink, see our water purification tablets guide.

What to look for when you buy

Light and handy: Honda WX10 1 inch Water Pump

Best for: Gardens, small ponds, boats and pool covers

Honda lists 32 gal/min, 26 ft suction lift, 121 ft total head, 52 psi, 13 lb and an included garden hose adaptor, suction hose, clamps and strainer.

Watch out: 0.9 hour run time at full flow on its small tank.

See options on Amazon (opens Amazon in a new tab)

Moves volume: Honda WB20 2 inch Water Pump

Best for: Draining flooded yards, pools and larger ponds

Honda lists 164 gal/min, 25 ft suction lift, 105 ft total head, a cast iron volute and 4-vane impeller, a silicon carbide seal, Oil Alert and 1.7 hours at full flow.

Watch out: 44 lb; not a trash pump, solids above about 5/16 inch can clog it.