PURPOSE: To facilitate the fitting of a timing belt by carving marks that the timing belt and pulleys are matched at a phase to stabilize a crank shaft, cam shaft and injection pump shaft independently in an engine interlocking these shafts and the belt.

CONSTITUTION: The compression pressure is applied to a crank shaft 1 from the No.1 or No.2 cylinder through a connecting rod at the oblique line portion, and the shaft 1 is rotated and stabilized on the area with the bottom dead point serving as a center, an injection pump cam 9 is depressed by the spring force applied to a roller 11 corresponding to the bottom dead point and is stabilized at the portion with no oblique line, and a suction/discharge cam 8 is depressed by the spring force applied to a rocker arm 10 and is stabilized in the area with an asterisk but not in the area of high pressure as shown by oblique lines. Therefore, when individual pulleys 3, 6, 7 are engaged with the timing belt 2 so that marks M1WM4 are matched at the bottom dead point, no tension is applied to the belt 2 in the rotation direction. The belt and pulleys are carved so that the marks M1WM4 are matched at this position.