Briggs and Stratton 386777

Briggs and Stratton 386777The Briggs and Stratton 386777 Vanguard is a 627 cc (38.2 cu·in) V-twin air-cooled four-stroke internal combustion gasoline engine, manufactured by Briggs and Stratton.

The B&S 386777 engine has an OHV (overhead valve) design and a vertical PTO shaft. This engine is equipped with float type, side-draft carburetor and an electronic ignition system. The B&S 386777 engine used Dual-Clean air cleaner (paper element with a foam pre-cleaner).

The cylinder bore is 75.5 mm (2.97 in) and the piston stroke is 70.0 mm (2.75 in). This engine produced 23.3 PS (17.1 KW; 23.0 HP) at 3,600 rpm of horsepower.

The breakdown of the engine code is as follows:

  • 38 – Displacement
  • 6 – Basic design series
  • 7 – Vertical PTO-shaft
  • 7 – Plain bearing, Pressure lubrication
  • 7 – Electric starter

General information

Engine Specifications
Model B&S 386777 Vanguard
Type 4-stroke, OHV, V-twin
Displacement 627 cm 3 (38.2 cu-in)
Max. horsepower 23.3 PS (17.1 KW; 23.0 HP) at 3,600 rpm
Max. torque
Fuel system Float type, side-draft carburetor
Cooling system Forced-air
Ignition system Electronic
Lubricating system Pressure lubrication, oil cooler
Starting system Electric starter
Fuel used Gasoline
Fuel tank capacity

Cylinder Block and Head

Cylinder block
Bore x Stroke 75.5 mm X 70.0 mm (2.97 x 2.76 in)
Sleeve internal diameter 75.500-75.520 mm (2.9724-2.9730 in)
Number of piston rings (compression / oil): 2 / 1
Side clearance Top 0.045-0.076 mm (0.0018-0.003 in)
Second 0.045-0.076 mm (0.0018-0.003 in)
Oil 0.110-0.150 mm (0.0043-0.0059 in)
Ring end gap Top 0.200-0.400 mm (0.0079-0.0157 in)
Second 0.200-0.400 mm (0.0079-0.0157 in)
Oil 0.200-0.400 mm (0.0079-0.0157 in)
Connecting rod small end ID 18.040-18.050 mm (0.7100-0.7105 in)
Piston pin outer diameter 18.000-18.010 mm (0.7085-0.7090 in)
Cylinder Head
Valve Arrangement: OHV
Valves: 4 (2 per cylinder)
Valve steam diameter INTAKE 5.950-5.960 mm (0.2343-0.2346 in)
EXHAUST 5.940-5.950 mm (0.2339-0.2343 in)

Tightening torque

Tightening torque specs
Alternator (to cylinder) 2.0 Nm; 1.5 ft·lb
Air cleaner base (to carburetor) 7.0 Nm; 5.2 ft·lb
Air cleaner support bracket 7.0 Nm; 5.2 ft·lb
Armature 3.0 Nm; 2.2 ft·lb
Blower housings 7.0 Nm; 5.2 ft·lb
Back plate 7.0 Nm; 5.2 ft·lb
Breather 3.0 Nm; 2.2 ft·lb
Carburetor to manifold 7.0 Nm; 5.2 ft·lb
Connecting rod 13.0 Nm; 6.9 ft·lb
Crankcase cover 17.0 Nm; 12.6 ft·lb
Cylinder head 19.0 Nm; 14.1 ft·lb
Cylinder shield 7.0 Nm; 5.2 ft·lb
Exhaust manifold 17.0 Nm; 12.6 ft·lb
Flywheel nut 175.0 Nm; 129.6 ft·lb
Fan Retainer 17.0 Nm; 12.6 ft·lb
Governor lever nut 8.0 Nm; 5.9 ft·lb
Governor control bracket 16.0 Nm; 11.9 ft·lb
Intake manifold to cylinder head 16.0 Nm; 11.9 ft·lb
Oil pump 7.0 Nm; 5.2 ft·lb
Rewind starter (to blower housing) 7.0 Nm; 5.2 ft·lb
Rocker arm lock nut 7.0 Nm; 5.2 ft·lb
Rocker arm stud 11.0 Nm; 8.2 ft·lb
Starter motor 16.0 Nm; 11.9 ft·lb
Starter motor thru bolts 6.0 Nm; 4.4 ft·lb
Valve cover 3.0 Nm; 2.2 ft·lb

Service Information

Engine
Max speed 3,600 rpm
Valve clearance
Intake valve clearance 0.10-0.15 mm (0.004-0.006 in)
Exhaust valve clearance 0.10-0.15 mm (0.004-0.006 in)
Oil system
Oil type API SF, SG, SH, SJ or higher
Recommended oil Summer: SAE 30, 10W-30
Winter: SAE 5W-30
Oil capacity (with filter) 1.65 L (1.74 US. qt, 1.45 Imp. qt.)
Ignition system
Spark plug Champion RC12YC
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.

2 Comments

  1. hello
    great site! I am searching for the engine torque spec for a vanguard 3867 engine but cannot find it detailed anywhere, do you know where i can find it? and why its not detailed as it I want compare motors

  2. Looking for a complete engine overhaul kit. Where is the best place to purchase this from? briggs & stratton vanguard 23 hp commercial, Model:386777, Type:0114-E1, Code:06062011

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