Part of the Kubota Repair Manuals.
This Kubota RK Series Workshop Manual is the factory service reference for the RK diesel engine family, covering the RK50, RK60, RK70, RK80-1, RK95-1, RK105-2, and RK125-2 along with their N and H variants. It is a 125 page PDF you download and keep on any device, with a searchable text layer and bookmarks for fast navigation.
Inside you get full specifications, performance curves, appearance and dimension drawings, optional PTO equipment details, and a mechanism section explaining how each system works. The largest part of the book is the disassembling and servicing chapter, which walks through teardown, inspection, and reassembly with the exact tolerances and torque figures the factory uses.
Whether you are rebuilding a top end, chasing an oil pressure problem, or setting valve clearance, this manual gives owners and independent mechanics the numbers to do the job right.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Specifications | 3-4 | Engine Model and Type Specifications, Output and Speed Specifications, Combustion and Lubricating System Specifications, Cooling and Fuel System Specifications |
| Performance Curves | 5-6 | RK50 RK50-N RK50H Performance Curves, RK80-1 RK80-1-N RK80H-1 Performance Curves, RK95-1 RK95-1-N RK95H-1 Performance Curves, RK60 RK60-N RK60H Performance Curves |
| Appearance and Dimensions | 7-8 | Radiator Type Dimensions, Hopper Type Dimensions, Details of Flywheel |
| Optional Equipment | 9-10 | PTO Shaft Assembly with Bolt, Washer & Key, Pulley Flange Assembly, Flat Pulley, V-Pulley |
| Mechanism | 11-42 | Feature (Fuel Saving, Quiet/Low Vibration, Easy Operation/Starting, High Durability, New Design/Safety Engine) |
| Disassembling and Servicing | 43-125 | Engine Identification (Model Name and Engine Serial Number, Applying Grease to Oil Seal, Direction of Installing Snap Rings) |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Flywheel Nut Torque | 300 to 390 N-m | p. 44 |
| Cylinder Head Nuts Torque (RK50-60-70-80-1-95-1) | 98.1 to 117 N-m | p. 44 |
| RK50 Bore x Stroke | 72.0 x 75.0 mm | p. 3 |
| RK50 Lubricant Capacity | 2.0 ℓ | p. 3 |
| RK50 Fuel Tank Capacity | 7.5 ℓ | p. 3 |
| Cylinder Head Surface Flatness Allowable Limit | 0.05 mm | p. 48 |
| Compression Pressure Allowable Limit | 2.40 MPa | p. 48 |
| Valve Clearance (Cold) [RK50-95-1] | 0.16 to 0.20 mm | p. 48 |
| Engine Oil Pressure (At Idle Speed) | 50 kPa or more | p. 54 |
| Oil Pump Rotor Lobe Clearance | 0.15 mm or less | p. 54 |
| RK80-1 Injection Pressure | 21.6 to 22.5 MPa | p. 55 |
| Radiator Leakage Test Pressure | 180 kPa | p. 54 |
