there are a total of four scratch (white) marks for timing. three are real close together....te last one is farther away from the bunched 3 marks. when you set timing with the installation of the timing belt. you have to line up the last alone mark with the crank pully. then when you check the timing with the timing light....you match it accordingly to the three marks. middle is zero and the other two marks (from that 3) are 15 degrees or 5 or whatever.