running. Furthermore, this engine has one-piece cylinders, the bore is 8 mm (5/16 inch), and stroke 19 mm (3/4 inch). The SP5D Mk2 model comes fitted with a belt-driven dynamo and bulb holder. A version without the dynamo is also available. [ 3 ] A Mamod SP6 1338 stationary engine SP6 Introduced Replacing Discontinued Number