INJURED WAS HELPING INSTALL A CLUTCH ON A 671 ENGINE ON OUR DREDGE. CLUTCH WAS INSTALLED WITH AID OF HOIST AND CHAIN. AFTER CLUTCH WAS INSTALLED, WHILE THE ENGINE WAS NOT RUNNING, EMPLOYEE REA CHED INTO TOP OF CLUTCH TO REMOVE THE CHAIN. AN EMPLOYEE NEARBY LOST HIS BALANCE AND STRUCK THE CLUTCH LEVER ENGAGING THE CLUTCH AND SEVERING THE TIP OF INJURED'S FINGER.