| Model | KOSHIN STH-50X | KOSHIN STH-80X | KOSHIN STH-100X | KOSHIN STR-50EX | KOSHIN STR-80EX |
| Pump | Connection Dia | 50 mm (2″) | 80 mm (3″) | 100 mm (4″) | 50 mm (2″) | 80 mm (3″) |
| Connection Thread | Outer Pipe Thread BSP |
| Total Head | 29 m (95 ft) | 26 m (85 ft) | 28 m (92 ft) | 30 m (98 ft) | 28 m (92 ft) |
| Delivery Volume | 600 L/min (158 USG/min) | 900 L/min (238 USG/min) | 1450 L/min (383 USG/min) | 580 L/min (153 USG/min) | 930 L/min (246 USG/min) |
| Max. Suction Head | 8 m (26 ft) |
| Engine | Type | Forced Air-cooled 4-stroke Gasoline Engine |
| Model | Honda GX120 | Honda GX160 | Honda GX240 | Subaru EX16 | Subaru EX17 |
| Exhaust Volume | 118 cc | 163 cc | 270 cc | 169 cc | 169 cc |
| Rated Output | 2.1 kW (2.9 PS) / 3600 rpm | 2.9 kW (4.0 PS) / 3600 rpm | 4.6 kW (6.3 PS) / 3600 rpm | 2.2 kW (3.0 PS) / 3600 rpm | 2.9 kW (4.0 PS) / 3600 rpm |
| Max. Output | 2.6 kW (3.5 PS) / 3600 rpm | 3.6 kW (4.9 PS) / 3600 rpm | 5.9 kW (8.0 PS) / 3600 rpm | 3.2 kW (4.3 PS) / 4000 rpm | 4.2 kW (5.7 PS) / 4000 rpm2.0 L (0.53 USG) |
| Fuel | Automotive Unleaded Gasoline |
| Fuel Tank Capacity | 2.0 L (0.53 USG) | 3.1 L (0.82 USG) | 5.3 L (1.40 USG) | 3.6 L (0.95 USG) | 3.2 L (0.84 USG) |
| Continuous Oparating Time | Approx. 3 hrs | Approx. 2 hrs |
| Starting Method | Recoil Starter |
| Standard Accessories | 1 Strainer, 2 Hose Couplings, 3 Hose Bands, 1 Engine Tool Set, 1 Spanner |
| Gross Weight | 25 kg (55.1 lbs) | 35 kg (77.1 lbs) | 64 kg (141 lbs) | 28 kg (61.7 lbs) | 34 kg (74.9 lbs) |
| Dimensions LxWxH (mm) | 500 × 395 × 415 | 525 × 389 × 473 | 665 × 472 × 655 | 665 × 472 × 655 | 530 × 405 × 405 |
| Packing Unit | 1 |
