
The B&S 49M877 engine has an OHV (overhead valve) design and a vertical PTO shaft. This engine is equipped with float type carburetor and an electronic ignition system. The B&S 49M877 engine used Dual-Clean air cleaner (paper element with a foam pre-cleaner).
Cylinder bore and piston stroke are 83.81 mm (3.3 in) and 73.41 mm (2.89 in), respectively. This engine produced 30.5 PS (22.4 kW; 30.0 HP) at 3,600 rpm of horsepower.
The breakdown of the engine code is as follows:
- 49 – Displacement
- M – Basic design series
- 8 – Vertical PTO-shaft
- 7 – Plain bearing, Pressure lubrication
- 7 – Electric starter
General information
| Engine Specifications | |
| Model | B&S 49M877 | 
| Type | 4-stroke, OHV, V-twin | 
| Displacement | 810 cm3 (49.4 cu-in) | 
| Max. horsepower | 30.5 PS (22.4 kW; 30.0 HP) at 3,600 rpm | 
| Max. torque | – | 
| Fuel system | Float typet carburetor | 
| Cooling system | Forced-air | 
| Ignition system | Electronic | 
| Lubricating system | Full pressure lubrication system with spin-on oil filter | 
| Starting system | Electric starter | 
| Fuel used | Gasoline | 
| Fuel tank capacity | – | 
Cylinder Block and Head
| Cylinder block | ||
| Bore x Stroke | 83.81 mm X 73.41 mm (3.30 x 2.89 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Cylinder Head | ||
| Valve Arrangement: | OHV | |
| Valves: | 4 (2 per cylinder) | |
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) | 2.0 liters (2.11 US. qt, 1.76 Imp. qt.) | 
| Ignition system | |
| Spark plug | Champion RC12YC | 
| Spark plug gap | 0.7-0.8 mm (0.0276-0.0315 in) | 

Hello,
I dont see shaft diameter & length of Briggs 49M877 engine. Can you help w/ this?
1 1/8 x 4 5/16 is what I got when I asked Briggs and Stratton.