The Briggs and Stratton 252707 is a 399 cc (24.3 cu·in) single-cylinder air-cooled four-stroke internal combustion gasoline engine, manufactured by Briggs and Stratton.
The B&S 252707 engine has an L-head (side valve) design and a vertical PTO shaft. This engine is equipped with float type carburetor and an transistor module ignition system. The B&S 252707 engine used a dual element air cleaner: cartridge and pre-cleaner.
The cylinder bore is 87.30 mm (3.44 in) and the piston stroke is 66.7 mm (2.63 in). This engine produced 11.2 PS (8.2 kW; 11.0 HP) at 3,600 rpm of horsepower.
The breakdown of the engine code is as follows:
- 25 – Displacement
- 2 – Basic design series
- 7 – Vertical PTO-shaft
- 0 – Plain bearing
- 7 – Electric starter
General information
| Engine Specifications | |
| Model | B&S 252707 |
| Type | 4-stroke, L-head, single-cylinder |
| Displacement | 399 cm 3 (24.3 cu-in) |
| Max. horsepower | 11.2 PS (8.2 kW; 11 HP) at 3,600 rpm |
| Max. torque | 22.7 N·m (2.3 kg·m, 16.7 ft·lb) at 2,800 rpm |
| Fuel system | Carburetor |
| Cooling system | Forced-air |
| Ignition system | Transistor module |
| Lubricating system | – |
| Starting system | Electric starter |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Fuel tank capacity | – |
Cylinder Block and Head
| Cylinder block | ||
| Compression ratio: | – | |
| Bore x Stroke | 87.3 mm X 66.7 mm (3.44 x 2.63 in) | |
| Sleeve internal diameter | 87.290-87.310 mm (3.4366-3.4374 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Ring end gap | Compression ring | 0.89 mm (0.035 in) |
| Oil ring | 1.14 mm (0.0449 in) | |
| Connecting rod small end ID | 20.330-20.370 mm (0.8004-0.802 in) | |
| Piston pin outer diameter | 20.290-20.310 mm (0.7988-0.7996 in) | |
| Cylinder Head | ||
| Valve Arrangement: | L-head (sidevalve) | |
| Valves: | 2 | |
Tightening torque specs
| Tightening torque specs | |
| Cylinder Head | 18.6 Nm; 13.8 ft·lb |
| Connecting Rod | 20.9 Nm; 15.5 ft·lb |
| Flywheel Nut | 87.8 Nm; 65.0 ft·lb |
| Crankcase Cover | 15.8 Nm; 11.7 ft·lb |
| Fuel Shut-Off Valve | 8.0 Nm; 5.9 ft·lb |
| Governor Lever Nut | 7.0 Nm; 5.2 ft·lb |
| Spark Plug Torque | 18.0 Nm; 13.5 ft·lb |
| Oil Drain Plug | 20.0 Nm; 14.9 ft·lb |
Service Information
| Engine | |
| Max speed | 3,600 rpm |
| Valve clearance | |
| Intake valve clearance | 0.08-0.13 mm (0.003-0.005 in) |
| Exhaust valve clearance | 0.13-0.15 mm (0.005-0.006 in) |
| Oil system | |
| Oil type | API SE, SF or SG |
| Recommended oil | Summer: SAE 30, 10W-30 Winter: SAE 5W-20, 5W-30 |
| Oil capacity (with filter) | 1.4 L (1.48 US. qt, 1.23 Imp. qt.) |
| Ignition system | |
| Spark plug | Champion: CJ-8 or RJ19LM |
| Spark plug gap | 0.7-0.8 mm (0.0276-0.0315 in) |
Author:
interested all info on this engine came across a Roper Rally LO81 Riding lawnmower seeing what else could be a Good replacement if cant get this one running or or repaired.