PA B34 — 31–34 HP Reduction Gearbox

The PA B34 is a deluxe reduction gearbox from P.A. SpA (Italy), engineered for high-performance pressure washing systems requiring 31–34 HP (25 kW). Featuring hardened steel helical gears and an enlarged crankcase with increased oil capacity, the B34 delivers smooth, reliable power transfer from petrol engines to triplex plunger pumps — reducing input speed from 3,100 RPM down to approximately 1,450 RPM at the pump shaft. It is the ideal gearbox for builds using the Honda IGX800 engine and compatible with a wide range of pump brands.

Specifications

Model	B34
Manufacturer	PA (P.A. SpA, Italy)
Type	Reduction Gearbox (Deluxe)
Max Engine Power	31–34 HP (25 kW)
Input Speed	3,100 RPM
Output Speed	~1,450 RPM
Gear Type	Hardened steel helical gears
Gear Ratio	2.21:1
Oil Type	SAE 90
Oil Capacity	0.50 L (enlarged crankcase)
Engine Flange	SAE J609B
Input Shaft	1-1/8″ (28.6 mm)

Variants

50.0360.00

1-1/8″ (28.6 mm)

Variable (to suit pump)

Key Features

• Hardened steel helical gears for quiet, efficient power transfer and long service life
• Enlarged crankcase with 0.50 L oil capacity for enhanced cooling under sustained high-load operation
• Deluxe construction designed for engines up to 34 HP — accommodates Honda IGX800
• SAE J609B engine flange for secure, standardised engine mounting
• 2.21:1 gear ratio reduces engine speed from 3,100 RPM to ~1,450 RPM at the pump
• Compatible with Comet TW Series pumps (30 mm shaft)

Applications

• High-powered commercial and industrial pressure washers (31–34 HP engine builds)
• Drain jetting and sewer cleaning rigs
• Multi-gun pressure washing systems
• Hydro-blasting and surface preparation units
• Custom pump-engine packages using Honda IGX800 or equivalent engines

Pump Compatibility

The PA B34 gearbox is compatible with a wide range of high-pressure pump brands, including:

• AR (Annovi Reverberi)
• Bertolini
• Comet (including TW Series — 30 mm shaft)
• Interpump
• Hawk
• Udor

Technical Documents

• General Pump YGR Gear Reducer Datasheet (PA B18–B31 Range) (PDF)

Parts & Service

AES Waterblasters stocks genuine PA gearbox parts and can supply complete B34 units, seals, bearings, and gears. Whether you are building a new pressure washer or replacing a worn gearbox, our team can help you select the right configuration. Contact us on 09 271 4782 for pricing, availability, and technical advice.