The Subaru-Robin EX30D is a 287 cc (17.51 cu·in) single-cylinder air-cooled 4-stroke internal combustion small gasoline engine manufactured by Industrial Products division of Subaru Corporation for general-purpose applications.
The Subaru-Robin EX30D engine has an OHС (overhead camshaft) design; high compression ratio for better fuel efficiency; horizontal draft, float type carburetor; recoil starter or electric starter as option and transistorized magneto ignition system.
A 75.0 mm (2.95 in) cylinder bore and 65.0 mm (2.56 in) piston stroke give the motor a total 265 cc (16.17 cu-in) of displacement. The engine produced 9.0 PS (6.6 kW; 8.9 HP) at 4,000 rpm of maximum horsepower.
General information
| Engine Specifications | |
| Model | EX30D |
| Type | 4-stroke, OHC, single cylinder |
| Displacement | 287 cm 3 (17.51 cu-in) |
| Max. horsepower | 9.0 PS (6.6 kW; 8.9 HP) at 4,000 rpm |
| Max. torque (crank PTO) | – |
| Carburetor | Horizontal draft, float type carburetor |
| Cooling system | Forced-air |
| Ignition system | Transistorized magneto ignition |
| Lubricating system | Splash |
| Starting system | Recoil or electric starter |
| Stoping system | Ignition primary circuit ground |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| PTO shaft rotation | Counterclockwise (from PTO shaft side) |
Cylinder Block and Head
The EX30D has cast iron cylinder sleeve, ball bearing supported forged steel crankshaft, improved piston design. The piston has single compression rings and a single oil ring.
| Cylinder block | ||
| Bore x Stroke | 75.0 x 65.0 mm (2.95 x 2.56 in) | |
| Sleeve internal diameter | 75.000-75.019 mm (2.9528-2.9535 in) | |
| Piston skirt outer diameter | 74.980-75.000 mm (2.952-2.9528 in) | |
| Number of piston rings (compression / oil): | 1 / 1 | |
| Ring side clearance | Top | 0.035-0.080 mm (0.0014-0.0031 in)) |
| Oil | 0.0100-0.205 mm (0.0004-0.0081 in) | |
| Ring end gap | Top | 0.10-0.30 mm (0.0039-0.0118 in) |
| Oil | 0.20-0.70 mm (0.0079-0.0276 in) | |
| Connecting rod small end ID | 18.010-18.020 mm (0.7091-0.7094 in) | |
| Connecting rod big end ID | 34.500-34.516 mm (1.3583-1.3589 in) | |
| Piston pin outer diameter | 17.992-18.000 mm (0.7083-0.7087 in) | |
| Crankshaft crankpin outer diameter | 34.467-34.480 mm (1.357-1.3575 in) | |
| Crankshaft main journal diameter | 29.998-29.997 mm (1.181-1.181 in) | |
| Cylinder Head | ||
| Warpage (limit) | 0.10 mm (0.004 in) | |
| Valve Arrangement: | OHC | |
| Valves: | 2 | |
| Stem outer diameter (standard): | INTAKE | 5.440-5.455 mm (0.2142-0.2148 in) |
| EXHAUST | 5.425-5.445 mm (0.2136-0.2144 in) | |
| Valve spring free length: | 27.4 mm (1.0787 in) | |
| Camshaft lobe height: | INTAKE | 29.431-29.531 mm (1.1587-1.1626 in) |
| EXHAUST | 29.431-29.531 mm (1.1587-1.1626 in) | |
Tightening torque specs
| Tightening torque specs | |
| Cylinder head M8 × 68 flange bolt (Re-use) | 25-27 Nm; 2.5-2.7 kg·m; 18.1-19.5 ft·lb |
| Cylinder head M8 × 68 flange bolt (New) | 28-30 Nm; 2.8-3.0 kg·m; 20.3-21.7 ft·lb |
| Cylinder head M8 × 35 flange bolt | 17-19 Nm; 1.7-1.9 kg·m; 12.3-13.7 ft·lb |
| Connecting rod bolt | 17-20 Nm; 1.7-2.0 kg·m; 12.3-14.5 ft·lb |
| Main bearing cover bolts | 22-24 Nm; 2.2-2.4 kg·m; 16.2-17.7 ft·lb |
| Flywheel nut | 59-64 Nm; 5.9-6.4 kg·m; 42.7-46.3 ft·lb |
Service Information
| Engine | |
| Cylinder compression | 5.0 kg/cm2 |
| Valve clearance | |
| Intake valve clearance | 0.11-0.16 mm (0.0043-0.0063 in) |
| Exhaust valve clearance | 0.11-0.16 mm (0.0043-0.0063 in) |
| Oil system | |
| Oil type | 4-stroke or an equivalent (SE or SF) |
| Recommended oil | SAE 10W-30 |
| Oil capacity | 1.0 L (1.06 US. qt, 0.88 Imp. qt.) |
| Fuel system | |
| Type: | Horizontal draft, float type carburetor |
| Main jet: | #98 |
| Pilot screw opening: | 1-1/2 turns out |
| Ignition system | |
| Spark plug | NGK: BR-6HS; |
| Spark plug gap | 0.6-0.7 mm (0.0236-0.0276 in) |
| Spark plug torque: | 25 N·m (2.5 kg·m, 18.4 ft·lb) |
| Ignition coil air gap | 0.3-0.5 mm (0.0118-0.0118 in) |
Author:
I am looking for a carburetor mounting gasket for this engine
if i check oil level on the recoil side of the engine it’s good but if i check it on the air filter side oil runs out.why is there a difference in these dipsticks ?
Good afternoon, a lot of oil is coming out of the gas outlet of the valve cover and it comes out of the air filter, which must be happening, thank you for any help you can provide.