Engine is fired by denatured alcohol burner. Speed of engine is adjustable by variations of the length of the fiber wick. Flywheel has a grooved pulley to run an accessory. Piston and cylinder are permanently lubricated. The engine is 3.85 inches high. The diameter of the flywheel is 1.97 inches. This one is manufactured in Germany, under the name of Hog Motor. Note the quarter leaning against the base for a size comparison. This little guy really can 'move out' and will amaze you with its high RPM.