Koshin SEV Engine Driven Centrifugal Pumps
Koshin SEV pumps are petrol water pumps built entirely by Koshin, the Japanese pump maker: the pump end and the engine both come from Koshin, rather than an engine bought in from Honda or another maker. That keeps the price down without cutting corners on the pump, and Koshin backs every SEV with a guaranteed 8 metre suction lift. Koshin classes the SEV as a clear water pump, designed for irrigation, sprinklers, washing down and drawing from shallow wells, ponds and tanks.
The range covers three sizes: the 1″ SEV-25L, the 2″ SEV-50X and the 3″ SEV-80X. All three are self-priming centrifugal pumps. Once you have filled the casing with water, the pump draws water up its own suction hose, so it can sit on the bank or beside the tank rather than in the water. Each comes with a strainer, two hose couplings, three hose bands and an engine tool set.
Two-stroke or four-stroke: which SEV do you need?
The number in each model name is the connection size in millimetres: 25 for 1″, 50 for 2″ and 80 for 3″.
The SEV-25L is the lightweight option at 5.5 kg. It runs on a Koshin KC26 two-stroke engine, so it needs petrol pre-mixed with two-stroke oil at 50:1. It delivers up to 110 litres per minute and 32 metres of head, ideal for watering an allotment, running a hose from a water butt or emptying a small pond.
The SEV-50X and SEV-80X share the same Koshin K180 four-stroke engine, which runs on plain unleaded petrol and holds 3.6 litres, enough for well over two hours of pumping. Both reach 27 metres of head. Choose the 2″ SEV-50X for up to 620 l/min, or the 3″ SEV-80X when volume matters most: up to 1,050 l/min for filling tanks, flood irrigation and moving large amounts of water in a short time.
SEV specifications compared
| Model | Connections | Engine | Max flow (l/min) | Max head (m) | Max suction lift (m) | Fuel tank (L) | Run time per tank | Net weight (kg) |
|---|---|---|---|---|---|---|---|---|
| SEV-25L | 1″ | Koshin KC26 two-stroke, 26 cc | 110 | 32 | 8 | 0.6 | About 50 minutes | 5.5 |
| SEV-50X | 2″ | Koshin K180 four-stroke, 179 cc | 620 | 27 | 8 | 3.6 | About 2.6 hours | 25.2 |
| SEV-80X | 3″ | Koshin K180 four-stroke, 179 cc | 1,050 | 27 | 8 | 3.6 | About 2.4 hours | 28.7 |
Flow and head are Koshin’s maximum figures: maximum flow is measured with no head, and maximum head is the height at which flow stops. Click through to any model for full specifications.
Showing all 3 results
110 l/min · 32 m · Koshin KC26
Koshin SEV-25L 1" clear water pump with a Koshin KC26 two-stroke engine (50:1 petrol mix). Up to 110 l/min ...Read More£223.86 +VAT
620 l/min · 27 m · Koshin K180
Koshin SEV-50X 2" clear water pump with a Koshin K180 four-stroke petrol engine. Up to 620 l/min and 27 ...Read More£320.46 +VAT
1,050 l/min · 27 m · Koshin K180
Koshin SEV-80X 3" clear water pump with a Koshin K180 four-stroke petrol engine. Up to 1,050 l/min and 27 ...Read More£357.55 +VAT
Where to Use Koshin SEV Petrol Water Pumps
An SEV pump is a practical, portable way to move clean water wherever there is no mains supply. Typical jobs include irrigating crops, gardens and allotments from a river, pond or rainwater tank, feeding sprinklers, filling bowsers and troughs, washing down yards and machinery, and drawing water from shallow wells. Because the engine and fuel are on board, you can take the pump to the water rather than running cable to it.
Pick the pump by the flow you need at your actual duty, not by the maximum figure. Every metre the water climbs, every metre of suction lift and every length of hose reduces the output, and a pump working near its maximum head delivers very little. Our guide to pump head and flow rate shows how to work out your duty, and the suction lift guide explains why the pump should sit as close to the water surface as you safely can.
The SEV is a clear water pump, so it is not the right choice for muddy floodwater, slurry or water carrying stones and debris. For dirty water, look at the Koshin STH semi-trash pumps, and for heavier solids the Koshin KTH compact trash pumps. If you would rather have a Honda engine, the Koshin SEH Honda petrol pumps do the same clean water job, and for long, steep hose runs the Koshin SERH high pressure pumps give far more head. Another brand option is the Villiers RT petrol water pump range.
Frequently Asked Questions
Is the Koshin SEV a semi-trash pump?
No. Some sellers describe the SEV as semi-trash, but Koshin itself lists the SEV series as a clear water pump. Use it for clean water, drawn through its suction strainer. For water with mud and small solids, a semi-trash pump such as the Koshin STH is the correct choice.
What is the difference between the Koshin SEV and SEH pumps?
Both are Koshin clear water pumps; the difference is the engine. The SEV uses Koshin’s own engines, which keeps the cost down, while the SEH uses Honda engines. If you already service Honda engines or want a wider choice of sizes, the SEH range runs up to 4″; for a lower cost 1″, 2″ or 3″ pump, the SEV is the better value.
What fuel does the SEV-25L use?
The SEV-25L has a two-stroke engine and Koshin designs it only for petrol mixed with two-stroke oil at 50:1. Never put plain unleaded in it. The SEV-50X and SEV-80X have four-stroke engines that run on ordinary unleaded petrol, with engine oil in a separate sump.
How long will an SEV pump run on a tank of fuel?
Koshin quotes about 50 minutes for the SEV-25L on its 0.6 litre tank, about 2.6 hours for the SEV-50X and about 2.4 hours for the SEV-80X, both on a 3.6 litre tank. Koshin says its K180 engine runs around 50% longer per tank than the engine fitted to earlier SEV pumps.
Do I need to prime an SEV pump?
Yes, but only by filling the pump casing with water through the filler plug before you start the engine. The pump then lifts water up the suction hose by itself, from as much as 8 metres below the pump. Never run it dry: the mechanical seal relies on the water for cooling. Use a reinforced suction hose that will not collapse, and see our self-priming pumps guide for more detail. Hoses are not included.
For help choosing the right SEV pump, call the AES Rewinds team on 01252 515169 or email sales@aesrewinds.com. You can also browse all our petrol engine water pumps or the full range of engine driven pumps.
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