Hi! i have 1983 boat with a volvo penta aq 125 SOHC. the timing belt broke,so i bought a new one. problem is, there is no marks on the camshaft or anywhere else to reference to get the correct timing. does anyone have a diagram with the correct timing marks??? this boat is 27 years old, so any referencing marks are long gone from the original pieces...any help would be appreciated...thanks!