Briggs and Stratton 252707

B&S 252707The 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

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: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

ATTENTION! Dear visitors, this site is not a trading platform, an official dealer or a spare parts supplier, so we do not have any price lists or spare parts catalogs. We are an information portal and provide the technical specifications of gasoline and diesel engines.

We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.

1 Comment

  1. 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.

Leave a Reply

Your email address will not be published.