The Briggs and Stratton 331777 Intek is a 540 cc (32.9 cu·in) single-cylinder air-cooled four-stroke internal combustion gasoline engine, manufactured by Briggs and Stratton.
The B&S 331777 engine has an OHV (overhead) design and a vertical PTO shaft. This engine is equipped with float type carburetor, pulse type fuel pump and an electronic ignition system. The B&S 331777 engine used a paper air filter with a foam pre-cleaner. It is equipped with an electric starter (12V).
The cylinder bore is 94.0 mm (3.7 in) and the piston stroke is 77.8 mm (3.06 in). This engine produced 20.3 PS (14.9 kW; 20.0 HP) at 3,600 rpm of horsepower.
The breakdown of the engine code is as follows:
- 33 – Displacement
- 1 – Basic design series
- 7 – Vertical PTO-shaft
- 7 – Plain bearing, Pressure lubrication
- 7 – Electric starter
General information
| Engine Specifications | |
| Model | B&S 331777 Intek |
| Type | 4-stroke, OHV, single-cylinder |
| Displacement | 540 cm 3 (32.9 cu-in) |
| Max. horsepower | 20.3 PS (14.9 kW; 20.0 HP) at 3,600 rpm |
| Max. torque | – |
| Fuel system | Float type carburetor |
| Cooling system | Forced-air |
| Ignition system | Electronic |
| Lubricating system | Full pressure |
| Starting system | Electric starter |
| Fuel used | Gasoline |
| Fuel tank capacity | – |
Cylinder Block and Head
| Cylinder block | ||
| Bore x Stroke | 94.0 mm X 77.8 mm (3.70 x 3.06 in) | |
| Sleeve internal diameter | 94.010-94.110 mm (3.7012-3.7051 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Side clearance | Top | 0.051-0.076 mm (0.002-0.003 in) |
| Second | 0.051-0.076 mm (0.002-0.003 in) | |
| Oil | 0.051-0.076 mm (0.002-0.003 in) | |
| Ring end gap | Top | 0.150-0.250 mm (0.0059-0.0098 in) |
| Second | 0.300-0.510 mm (0.0118-0.0201 in) | |
| Oil | 0.510-0.630 mm (0.0201-0.0248 in) | |
| Connecting rod small end ID | 15.890-15.920 mm (0.6256-0.6268 in) | |
| Piston pin outer diameter | 15.850-15.890 mm (0.624-0.6256 in) | |
| Cylinder Head | ||
| Valve Arrangement: | OHV (overhead) | |
| Valves: | 2 | |
| Valve steam diameter | INTAKE | 5.920-5.970 mm (0.233-0.235 in) |
| EXHAUST | 5.920-5.970 mm (0.233-0.235 in) | |
Tightening torque specs
| Tightening torque specs | |
| Air cleaner base | 6.0 Nm; 4.4 ft·lb |
| Alternator | 2.0 Nm; 1.5 ft·lb |
| Armature | 3.0 Nm; 2.2 ft·lb |
| Blower housings | 10.0 Nm; 7.4 ft·lb |
| Breather | 3.0 Nm; 2.2 ft·lb |
| Carburetor to intake manifold | 8.0 Nm; 5.9 ft·lb |
| Carburetor solenoid | 5.0 Nm; 3.7 ft·lb |
| Connecting rod | 17.0 Nm; 12.6 ft·lb |
| Control bracket | 5.0 Nm; 3.7 ft·lb |
| Crankcase sump | 25.0 Nm; 18.5 ft·lb |
| Cylinder head | 25.0 Nm; 18.5 ft·lb |
| Cylinder shield | 5.0 Nm; 3.7 ft·lb |
| Exhaust manifold / adapter | 19.0 Nm; 14.0 ft·lb |
| Flywheel nut | 135.0 Nm; 100.0 ft·lb |
| Flywheel fan | 16.0 Nm; 11.9 ft·lb |
| Fuel pump | 10.0 Nm; 7.4 ft·lb |
| Governor lever nut | 5.0 Nm; 3.7 ft·lb |
| Intake manifold to cylinder head | 10.0 Nm; 7.4 ft·lb |
| Muffler | 10.0 Nm; 7.4 ft·lb |
| Oil drain plug | 11.0 Nm; 8.1 ft·lb |
| Oil fill tube | 10.0 Nm; 7.4 ft·lb |
| Oil pump cover | 10.0 Nm; 7.4 ft·lb |
| Regulator / Rectifier | 5.0 Nm; 3.7 ft·lb |
| Rewind starter | 3.0 Nm; 2.2 ft·lb |
| Rocker ball set screw or nut | 5.0 Nm; 3.7 ft·lb |
| Rocker cover | 7.0 Nm; 5.2 ft·lb |
| Starter motor | 16.0 Nm; 11.9 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 | 0.13-0.18 mm (0.005-0.007 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) | 1.40 L (1.48 US. qt, 1.23 Imp. qt.) |
| Ignition system | |
| Spark plug | Champion RC12YC |
| Spark plug gap | 0.7-0.8 mm (0.0276-0.0315 in) |
Author:
What’s the cost???? my engine has locked up… possible oil lose…I need a new engine…
What’s the cost of this engine???? my engine has locked up… possible oil lose…I need a new engine…
My engine is mounted on a DR mower/ snow thrower. I’ve had two engines lock-up. Repair facility said in both cases the push rods broke.
DR said the best they would do is replacement at half off even though second engine had less than an hour on it. Their locale distributer/repair wrote it was definitely a faulty engine! Wish I had my money back. When it worked it was GREAT, but it was down more than it worked.