Timing

See if this helps. The two upper marks are tiny notches in the metal covers behind the cam sprockets. The crankshaft mark is a round dot in the sprocket next to one tooth. It's real hard to see.

Don't rely on the spring to tension the belt. Sometimes the pivot sticks and the pulley doesn't move enough. That leaves the belt loose and overheating can result from the belt slipping over the water pump.