Disassembling a Briggs and Stratton engine is necessary to replace major components, such as the valves or piston, or to perform a thorough cleaning on the internal parts. Keep in mind that location of certain parts may vary depending on your Briggs and Stratton engine. Spend some time looking over your engine to get a sense of where everything is located. Also, refer to any documentation that came with your engine before beginning. It will definitely help to have a basic familiarity with your engine before trying to take it apart.
Drain the fuel and oil from your engine.
Remove the blower housing. There are two bolts attaching the housing to the engine. One is near the cylinder head, the other at the base of the engine. Use a socket wrench to remove the bolts and lift the housing from the engine.
Remove the cylinder shroud and slide shroud. The cylinder shroud is located above the crankshaft. Remove the single screw holding it in place to remove. The slide shroud is located next to the flywheel. Remove the bolt holding it in place to remove.
Remove the two bolts holding the muffler in place. Slide the muffler away from the engine to remove it.
Disconnect the engine's kill switch from the magneto. Bend the governor blade's retaining clips until they are straight. Slide the governor blade out of its socket.
Remove the two intake manifold bolts. The bolts will typically be located next to the exhaust port, where the muffler was attached.
Turn the engine upside down. Remove the mounting bolt attaching the fuel system assembly to the engine from the engine's base. Pull the entire fuel system assembly from the engine block.
Remove the valve spring cover, located on the side of the engine. The cover will likely have a rubber tube attached to it.
Remove the cylinder head, located at the top of the engine. Use a socket wrench to remove the spark plug. Remove the bolts holding the cylinder head in place. Slide the spark plug wire out of the way, and lift the cylinder head from the engine block, revealing the piston and valves.
Turn the engine over and remove the bolts holding the crankcase cover in place. Slide the crankcase cover from the engine block.
Rotate the flywheel with your hand until the exhaust valve is completely raised. Slide a flat head screwdriver, or some other flat object, under the valve to keep it raised. Rotate the flywheel again until the intake valve is raised. Place another flat object under it to keep it raised.
Slide the camshaft out away from the engine, and both tappets will fall out. Slide the crankshaft gear from the crankshaft.
Use a flywheel iron to hold the flywheel stationary. Unscrew the flywheel nut and remove it. Slide the flywheel out of the engine block.
Keeping your engine well-oiled and maintained will prevent the need for major overhauls.