Kubota KX121-3 Mini Excavator – Parts, Specs & Serial Numbers

Description:

The Kubota KX121-3 Mini Excavator is a high-performance compact machine built for demanding excavation tasks in tight spaces. Featuring a powerful 45-hp engine and advanced hydraulic system, the KX121-3 is favored by contractors for its exceptional digging power, durability, and ease of maintenance.

Equipped with an optional angle blade, strong bucket breakout force, and comfort-focused cab, the KX121-3 is perfect for trenching, grading, utility work, and light demolition. Its smooth pilot controls and tough undercarriage make it a long-lasting asset on any job site.

Key Specifications & Features

Engine

• Model: Kubota V2203-M

• Type: 4-cylinder, liquid-cooled, diesel

• Displacement: 2.197 L (134 cu in)

• Power Output: 45.4 hp (33.9 kW) @ 2,300 RPM

Hydraulics

• Pump Flow (Total): 26.6 GPM

• Auxiliary Hydraulic Flow: 12.7 GPM

• Hydraulic Pressure: 3,128 psi (216 bar)

• Boom Swing Angle: Left 70°, Right 55°

• Angle Blade (Optional): ±25° blade tilt

Transmission & Travel

• Travel Speed: Low – 1.8 mph | High – 3.1 mph

• Swing Speed: 9.1 RPM

• Traction Force: 10,593 lbf

Dimensions

• Operating Weight: 9,350 lbs (4,241 kg)

• Max Digging Depth: 11 ft 6 in (3.5 m)

• Max Reach at Ground: 18 ft 4 in (5.6 m)

• Track Width: 15.7 in (400 mm)

Performance

• Bucket Breakout Force: 9,535 lbf

• Arm Digging Force: 4,078 lbf

Maintenance Essentials & Common Parts

• Hydraulic cylinder rebuild kits

• Rubber tracks & undercarriage

• Final drive motors

• Swing motors and seals

• Control valves and O-ring kits

Pro Tip:

Regularly check track tension and adjust via the grease-filled adjuster behind the dozer blade. Over-tightened tracks wear out prematurely and reduce efficiency.

Common Issues & Quick Fixes

Hydraulic Drifts or Cylinder Leaks

Frequent on older models. Rebuild using Kubota cylinder seal kits for cost-effective repair.

Weak Final Drive

A loss of drive power is often due to internal gear failure or motor seals—replace with a Kubota final drive motor.

Starting Issues in Cold Weather

Typically caused by glow plug or fuel filter failure. Stock up on engine parts and filters.

Serial Number Location

Find the serial number plate on the front of the operator’s cab, just below the window line on the right side. Always verify this number when ordering parts for accuracy.