Motorcycles are high-compression, high-revving engines that typically do not last as long as automobile engines. You can expect to rebuild your motorcycle's engine at about 100,000 miles or less, depending on the size of the engine. For a top-end overhaul, you would remove the cylinder head and replace the pistons, rods and rings.
Remove the four bolts that secure the rocker cover to the top of the cylinder head. In some cases, the bolts require a 16-point socket. This is common in Harley-Davidson Evolution engines. Most other motors will require a standard hex-head socket. Pull the rocker cover off of the valve box.
Remove the four nuts that secure the valve box to the cylinder head with a socket and ratchet. Pull the valve box off of the cylinder head.
Remove the two bolts on the cylinder head that secure the intake manifold. This typically requires a hex-head socket, but in some cases, the heads on the bolts might require an Allen wrench.
Pull straight up on the cylinder head to remove it from the crankcase.