Yanmar 2TNV70, 3TNV70 & 3TNV76 specifications and torque values
All factory values for the Yanmar 2TNV70, 3TNV70 and 3TNV76 in one clear overview: that's this blog. From valve clearance and compression pressure to the complete torque-value tables from the official Yanmar workshop manual — including the tightening sequence for the cylinder head bolts for both the 2- and 3-cylinder. Handy to bookmark for the workshop.
Suitable for the entire series: Yanmar 2TNV70, 3TNV70 and 3TNV76 (Komatsu 2D70E, 3D70E, 3D76E). All values come directly from the workshop manual; unknown values are indicated with "—".
Yanmar TNV service information: the key values
| Check point | Standard | Limit value |
|---|---|---|
| Valve clearance intake and exhaust (cold) | 0.15–0.25 mm | — |
| Injector opening pressure | 11.8–12.8 MPa (120–130 kgf/cm²) | — |
| Compression 2TNV70 / 3TNV70 (250 rpm) | 3.24 ± 0.1 MPa | 2.55 ± 0.1 MPa |
| Compression 3TNV76 (250 rpm) | 3.43 ± 0.1 MPa | 2.75 ± 0.1 MPa |
| Max. difference between cylinders | 0.2–0.3 MPa | |
| Oil pressure at rated speed | 0.29–0.44 MPa | — |
| Oil pressure at idle | min. 0.06 MPa | — |
| Thermostat opens | 70–73 °C | Fully open (lift ≥ 8 mm) at 85 °C |
| Coolant temperature switch | 107–113 °C | — |
| Injection timing (BTDC ± 1°) | 15° at 2000–2100 rpm, 16° at 2200(–2600) rpm, 18° at 2300/2700–3000 rpm, 20–21° at 3000–3600 rpm (per variant and class, see manual ch. 7) | |
Yanmar 2TNV70, 3TNV70 & 3TNV76: specifications per model
| Specification | 2TNV70 | 3TNV70 | 3TNV76 |
|---|---|---|---|
| Cylinders | 2 | 3 | 3 |
| Bore × stroke | 70 × 74 mm | 70 × 74 mm | 76 × 82 mm |
| Displacement | 0.570 L | 0.854 L | 1.115 L |
| Max. power (net) | 8.1–14.6 hp | 9.1–21.7 hp | 12.2–26.5 hp |
| Firing order | 1-2 | 1-3-2 | 1-3-2 (cylinder 1 at flywheel side) |
| Dry engine weight | 66 kg | 83 kg | 110 kg |
| Oil pan (max/min dipstick) | 1.6/0.8 L (VM, VH) · 2.3/1.3 L (CH) | 2.8/1.5 L (CL, VM, VH) · 3.5/2.0 L (CH) | 3.4/1.8 L |
| Coolant (engine only) | 0.9 L | 0.9 L | 0.9 L |
| Coolant radiator circuit | 0.6 L | 0.9 L | 0.9 L |
| Cooling fan | 290 mm, 5 blades, pusher | 5 blades, pusher | 335 mm, 6 blades, pusher |
| Battery (recommended) | 12V 36 Ah | 12V 52 Ah | 12V 36 Ah |
Yanmar TNV torque values: special engine values
These values apply specifically to the parts listed and take precedence over the standard table. Note the "lubricate thread" column: Yanmar specifies for each bolt whether the thread and bearing surface should be lightly oiled before assembly.
| Part | Thread × pitch | Torque value | Lubricate thread |
|---|---|---|---|
| Cylinder head bolts | M9 × 1.25 mm | 53.9–57.9 N·m (5.5–5.9 kgf·m) | Yes |
| Connecting rod bolts | M7 × 1.0 mm | 22.6–27.5 N·m (2.3–2.8 kgf·m) | Yes |
| Flywheel bolts | M10 × 1.25 mm | 80.4–86.4 N·m (8.2–8.8 kgf·m) | Yes |
| Main bearing cap bolts | M10 × 1.25 mm | 75.5–81.5 N·m (7.7–8.3 kgf·m) | Yes |
| Crankshaft pulley bolt (FC250 pulley) | M12 × 1.25 mm | 83.3–93.3 N·m (8.5–9.5 kgf·m) | Yes |
| Crankshaft pulley bolt (S48C pulley) | M12 × 1.25 mm | 113–123 N·m (11.5–12.5 kgf·m) | Yes |
| Glow plug | M10 × 1.25 | 14.7–19.6 N·m (1.5–2.0 kgf·m) | No |
Tightening the Yanmar TNV cylinder head: sequence and steps
Lightly oil the head bolts and tighten them in two steps, each time in the numbered sequence from inside to outside:
| Step | Torque |
|---|---|
| Step 1 | 1/2 of final torque (± 27–29 N·m) |
| Step 2 | Final torque: 53.9–57.9 N·m |
3-cylinder (3TNV70 and 3TNV76, 14 head bolts):
2-cylinder (2TNV70, 10 head bolts):
Yanmar TNV torque values fuel system
| Part | Torque value | Lubricate thread |
|---|---|---|
| Injector (in head) | 39.2 N·m (4 kgf·m) | No |
| Fuel pump drive gear nut | 59–69 N·m (6–7 kgf·m) | No |
| High-pressure line union nuts | 29–34 N·m (3.0–3.5 kgf·m) | No |
| Return line nuts | 24–33 N·m (2.5–3.3 kgf·m) | No |
| Injection pump mounting nuts | 23–28 N·m (2.3–2.9 kgf·m) | No |
| Nozzle holder union nut injector | 49–53 N·m (5.0–5.4 kgf·m) | No |
Yanmar TNV torque values maintenance
| Part | Torque value |
|---|---|
| Oil drain plug oil pan | 19.6–23.5 N·m (2.0–2.4 kgf·m) |
| Oil filter | Hand-tight until seated + 3/4 turn with filter wrench (lightly oil the gasket) |
Yanmar TNV standard torque values: bolts and nuts
For fasteners not listed in the special tables, the standard values apply. This table applies only to bolts marked "7" on the head (JIS strength class 7T). Yanmar specifies: 80% of the table value when mounted in aluminum, 60% for 4T bolts and lock nuts. Do not lubricate the thread or bearing surface.
| Item | Thread × pitch | Torque value |
|---|---|---|
| Hex bolt (7T) and nut | M6 × 1.0 mm | 9.8–11.8 N·m (1.0–1.2 kgf·m) |
| M8 × 1.25 mm | 22.6–28.4 N·m (2.3–2.9 kgf·m) | |
| M10 × 1.5 mm | 44.1–53.9 N·m (4.5–5.5 kgf·m) | |
| M12 × 1.75 mm | 78.4–98.0 N·m (8.0–10 kgf·m) | |
| M14 × 1.5 mm | 127.5–147.1 N·m (13–15 kgf·m) | |
| M16 × 1.5 mm | 215.7–235.4 N·m (22–24 kgf·m) | |
| PT plug | 1/8 | 9.8 N·m (1.0 kgf·m) |
| 1/4 | 19.6 N·m (2.0 kgf·m) | |
| 3/8 | 29.4 N·m (3.0 kgf·m) | |
| 1/2 | 58.8 N·m (6.0 kgf·m) | |
| Banjo bolt (pipe joint bolt) | M8 | 12.7–16.7 N·m (1.3–1.7 kgf·m) |
| M10 | 19.6–18.734 N·m* (2.0–3.5 kgf·m) | |
| M12 | 24.5–34.3 N·m (2.5–3.5 kgf·m) | |
| M14 | 39.2–49.0 N·m (4.0–5.0 kgf·m) | |
| M16 | 49.0–58.8 N·m (5.0–6.0 kgf·m) |
* Value taken literally from the manual; the N·m upper limit appears to contain a typo there. Use the kgf·m value (2.0–3.5) as the authoritative figure.
Yanmar TNV standard torque chart (with tolerance)
| Thread × pitch (mm) | M6×1.0 | M8×1.25 | M10×1.5 | M12×1.75 | M14×1.5 | M16×1.5 |
|---|---|---|---|---|---|---|
| N·m | 10.8 ± 1.0 | 25.5 ± 2.9 | 49.0 ± 4.9 | 88.3 ± 9.8 | 137 ± 9.8 | 22.6 ± 9.8* |
| kgf·m | 1.1 ± 0.1 | 2.6 ± 0.3 | 5.0 ± 0.5 | 9.0 ± 1.0 | 14.0 ± 1.5 | 23.0 ± 2.0 |
* Value taken literally; here too, the manual appears to contain a typo in the M16 N·m row. The kgf·m row (23.0 ± 2.0) is authoritative.
Getting started on the head or block? Order the correct cylinder head bolts 3TNV70 (SKU-780017) or cylinder head bolts 3TNV76 (SKU-780013), connecting rod bolts (SKU-780022) and a fresh head gasket right away — you don't want to reuse head bolts and gaskets after disassembly.
