Udor S151 Diaphragm Pump Reduction Gearbox

The Udor S151 is a precision-engineered reduction gearbox designed to couple petrol or diesel engines directly to Udor diaphragm pumps for agricultural spraying, horticultural, and pest control applications. With a 5:1 gear ratio and a maximum power rating of 4 HP, the S151 provides the ideal speed reduction to drive small-to-medium diaphragm pumps at their optimal operating RPM — protecting both pump and engine from excessive wear.

Available with multiple engine shaft options to suit a wide range of popular Honda, Briggs & Stratton, Robin Subaru, and other small engines commonly used in New Zealand farming and spraying setups. AES Waterblasters is the sole authorised Udor distributor in New Zealand, carrying the full range of gearboxes and genuine spare parts.

Specifications

Model	S151
Type	Reduction Gearbox
Max Power	4 HP (3 kW)
Gear Ratio	5:1
Engine Shaft Options	15 mm, 18 mm, 5/8″, 3/4″
Drive Type	Petrol / Diesel Engine
Application	Diaphragm Pump Drive
Manufacturer	Udor S.p.A. (Italy)

Compatible Pumps

The S151 gearbox is designed to work with the following Udor diaphragm pumps:

• Udor IOTA 20 — compact, lightweight diaphragm pump for low-volume spraying
• Udor IOTA 25 — versatile mid-range diaphragm pump for agricultural and horticultural use
• Udor KAPPA 25 — robust diaphragm pump for demanding spraying applications
• Udor KAPPA 32 — higher-capacity diaphragm pump for broadacre and orchard spraying

Engine Shaft Variants

Select the correct S151 gearbox variant to match your engine’s crankshaft diameter:

15 mm shaft	Suits many Honda GX120/GX160 and similar small engines
18 mm shaft	Common on Honda GX160/GX200 and Robin Subaru engines
5/8″ (15.9 mm) shaft	Briggs & Stratton and select American-made engines
3/4″ (19.05 mm) shaft	Larger Briggs & Stratton, Kohler, and other engines

Applications

• Agricultural crop spraying — pasture, broadacre, and row crops
• Horticultural spraying — orchards, vineyards, and nurseries
• Weed spraying and spot spraying on farms and lifestyle blocks
• Pest control and biosecurity spraying
• Roadside and vegetation management
• Water transfer and tank-to-tank pumping
• ATV/UTV-mounted and tractor-mounted spray rigs

Key Features

• 5:1 reduction ratio converts engine speed to optimal pump RPM
• Compact, lightweight aluminium housing for easy mounting
• Sealed gear train with long-life lubrication
• Multiple engine shaft sizes for broad engine compatibility
• Direct bolt-on coupling to Udor IOTA and KAPPA diaphragm pumps
• Italian-manufactured precision gearing for smooth, quiet operation
• Low maintenance — designed for years of reliable field service
• Ideal for engine-driven spray rigs where PTO drive is not available

Technical Documents

• Udor S151 Technical Documents
• All Udor Diaphragm Pump Documents

Parts & Service

AES Waterblasters carries genuine Udor spare parts and complete gearbox assemblies for the S151 and all Udor reduction gearboxes. We can supply replacement seals, bearings, gears, and engine shaft adapters. Our experienced team can advise on the correct gearbox and pump combination for your spraying setup. Contact us on 09 271 4782 or email sales@aesblasters.co.nz for pricing and availability.

Related Models

Other Udor diaphragm pump accessories and compatible pumps:

• Udor IOTA 20 Diaphragm Pump
• Udor IOTA 25 Diaphragm Pump
• Udor KAPPA 25 Diaphragm Pump
• Udor KAPPA 32 Diaphragm Pump