Briggs and Stratton 42A707

Briggs and Stratton 42A707The Briggs and Stratton 42A707 is a 694 cc (42.35 cu·in) two-culinder air-cooled four-stroke internal combustion gasoline engine, manufactured by Briggs and Stratton.

The B&S 42A707 engine has an L-head (side valve) design and a vertical PTO shaft. This engine is equipped with float type carburetor and a flywheel magneto ignition system. The B&S 42A707 engine used a full pressure lubrication system.

A 87.3 mm (3.44 in) cylinder bore and 58.0 mm (2.28 in) piston stroke give the B&S 42A707 engine a total of 694 cc of displacement.

This engine produced 18.1 PS (13.3 kW; 18.0 HP) at 3,600 rpm of horsepower and 38.7 N·m (3.9 kg·m, 28.4 ft·lb) at 2,600 rpm of torque.

The breakdown of the engine code is as follows:

  • 42 – Displacement
  • A – Basic design series
  • 7 – Vertical PTO-shaft
  • 0 – Ball bearing
  • 7 – Electric starter

General information

Engine Specifications
ModelB&S 42A707
Type4-stroke, L-head, opposed-twin
Displacement694 cm 3 (42.3 cu-in)
Max. horsepower18.1 PS (13.3 kW; 18.0 HP) at 3,600 rpm
Max. torque38.7 N·m (3.9 kg·m, 28.4 ft·lb) at 2,600 rpm
Fuel systemFloat type carburetor
Cooling systemForced-air
Ignition systemFlywheel magneto
Lubricating systemFull pressure lubrication
Starting systemElectric starter
Fuel usedGasoline
Fuel tank capacity

Cylinder Block and Head

Cylinder block
Bore x Stroke87.3 mm X 58.0 mm (3.44 x 2.28 in)
Sleeve internal diameter87.280-87.310 mm (3.4362-3.4374 in)
Number of piston rings (compression / oil):2 / 1
Side clearanceTop0.090-0.150 mm (0.0035-0.0059 in)
Second0.090-0.150 mm (0.0035-0.0059 in)
Oil0.090-0.150 mm (0.0035-0.0059 in)
Ring end gapTop0.180-0.430 mm (0.0071-0.0169 in)
Second0.180-0.430 mm (0.0071-0.0169 in)
Oil0.180-0.430 mm (0.0071-0.0169 in)
Connecting rod small end ID20.340-20.350 mm (0.8008-0.8012 in)
Piston pin outer diameter20.320-20.330 mm (0.8000-0.8004 in)
Cylinder Head
Valve Arrangement:L-head
Valves:4 (2 per cylinder)
Valve steam diameterINTAKE7.820-7.870 mm (0.3079-0.3098 in)
EXHAUST7.820-7.870 mm (0.3079-0.3098 in)

Tightening torque

Tightening torque specs
Alternator (to cylinder)2.0 Nm; 1.5 ft·lb
Air cleaner base (to carburetor)3.0 Nm; 2.2 ft·lb
Armature3.0 Nm; 2.2 ft·lb
Blower housings10.0 Nm; 7.4 ft·lb
Breather3.0 Nm; 2.2 ft·lb
Carburetor to intake manifold11.0 Nm; 8.1 ft·lb
Connecting rod22.0 Nm; 16.3 ft·lb
Crankcase sump/cover25.0 Nm; 18.5 ft·lb
Cylinder head18.0 Nm; 13.3 ft·lb
Carburetor to solenoid11.0 Nm; 8.1 ft·lb
Fan Retainer17.0 Nm; 12.6 ft·lb
Flywheel nut203.0 Nm; 150.0 ft·lb
Governor lever nut11.0 Nm; 8.1 ft·lb
Intake manifold to cylinder head10.0 Nm; 7.4 ft·lb
Starter motor18.0 Nm; 13.3 ft·lb

Service Information

Max speed3,600 rpm
Valve clearance
Intake valve clearance0.15-0.20 mm (0.006-0.008 in)
Exhaust valve clearance0.23-0.28 mm (0.009-0.011 in)
Oil system
Oil typeAPI SF, SG, SH, SJ or higher
Recommended oil Summer: SAE 30, 10W-30
Winter: SAE 5W-30
Oil capacity (with filter)1.70 L (1.8 US. qt, 1.5 Imp. qt.)
Ignition system
Spark plugChampion RJ-12, AC R-46, Autolite 308
Spark plug gap0.7-0.8 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.

Be the first to comment

Leave a Reply

Your email address will not be published.