Hawk B5 — 6.5 HP Reduction Gearbox

The Hawk B5 is a compact reduction gearbox engineered for petrol engine–driven pressure washer systems up to 6.5 HP (4.8 kW). Manufactured by Leuco S.p.A. in Italy under the Hawk brand, the B5 reduces engine crankshaft speed from 3,400 RPM down to 1,450 RPM — the optimal operating speed for Hawk’s smaller triplex plunger pumps. With a 2.3:1 gear ratio, SAE J609A engine flange, and a featherweight 2.1 kg construction, this gearbox is purpose-built for lightweight, portable wash-down units powered by Honda GX200 and similar class engines. AES Waterblasters is an authorised Hawk distributor in New Zealand, supplying genuine gearboxes and spare parts nationwide.

Specifications

Specification	Value
Code	1.099-675.0
Model	B5
Manufacturer	Hawk (Leuco S.p.A., Italy)
Type	Reduction Gearbox
Max Engine Power	4.8 kW (6.5 HP)
Input Speed	3,400 RPM
Output Speed	1,450 RPM
Gear Ratio	2.3:1
Engine Shaft	3/4″ (19 mm)
Pump Shaft	24 mm
Engine Flange	SAE J609A
Oil	SAE 90 (0.15 L / 4.5 oz)
Weight	2.1 kg
Mounting	M6 bolts, 90 mm PCD

Applications

• Portable petrol-powered pressure washers for residential and light commercial use
• Mobile wash-down units for vehicle grooming, boat cleaning, and fleet maintenance
• Small engine–driven waterblasting rigs on trailers and ute-mounted skids
• Agricultural equipment cleaning — quad bikes, implements, dairy shed exteriors
• Construction site wash-down where mains power is unavailable

Key Features

• Ultra-lightweight 2.1 kg aluminium housing — ideal for portable, hand-carry pressure washer builds
• 2.3:1 gear ratio converts 3,400 RPM engine speed to 1,450 RPM at the pump for optimal flow and pressure
• SAE J609A flange provides a standardised, bolt-on connection to Honda GX200 and equivalent 6.5 HP engines
• 24 mm output shaft mates directly to Hawk NST, HD, NHD, NHDP 120, and NHDP 150 pump series
• Low oil volume (0.15 L SAE 90) simplifies maintenance and reduces weight
• M6 bolt mounting on a 90 mm pitch circle diameter for secure pump attachment
• Manufactured in Italy by Leuco S.p.A. to Hawk’s exacting quality standards

Technical Documents

• Hawk B5/B10 Gearbox – Parts Schematic (PDF)

Parts & Service

AES Waterblasters carries a comprehensive range of genuine spare parts for Hawk gearboxes, including seals, bearings, gears, and complete rebuild kits. Whether you need a routine oil change or a full overhaul, our team can supply the correct parts and advise on installation. Contact us on 09 271 4782 or email info@aesblasters.co.nz for pricing and availability.

Related Models

Other Hawk Gearboxes:

• Hawk B10 — 10 HP Reduction Gearbox
• Hawk 13 kW Gearbox — NMT/NPM
• Hawk 24 HP Gearbox — XLTI/PXI/XXT