Support the engine in a convenient position by gripping in a vice the front flange of the crankcase, supporting the rear of the engine from the bench by means of a steel bar bent to fit into one of the bolt holes and set to rest firmly on the bench. This takes a lot of the weight and prevents the Engine sliding down in the vice.
Take off the Cylinder Head as described on pages 32 and 34. With the flat of the hands against the front and rear of the Cylinder, push it sharply backwards and forwards alternately, exerting an upward pressure at the same time, to loosen the cylinder in the Crankcase. When free, pull it up carefully off the Piston. It is advisable to have an assistant to support the Piston as it is freed from the Cylinder in order to avoid damage. as Standard Two compression plates are fitted under the Cylinder.
Make a note before removing the piston which side of the engine the slot for the removal of the circlip is situated, or mark the piston so that it is put back into the same position. The flat machined face on the piston crown below the exhaust valve is marked "EX."
Remove one of the circlips from the piston and drive out the gudgeon pin from the opposite side. A soft metal punch must be used against the end of the pin to prevent damage. An assistant is essential when driving out the pin, so that the piston is supported on the opposite side to avoid damaging the connecting rod by setting it out of line.
The pin is a light driving fit with the piston cold.