Timing Belt Change Question

[Lfen]

The bottom Pic Here is what we are talking about. The White line on the Cam Sprocket. This is where it should be after the final spring/sprung position at 9:00, then when you turn it 90 degrees more it will be lined up with with the timing mark on Left head. But you will have to hold it there because it will try to rotate counterclockwise back to the 9:00 position. I held mine in place with a long breaking bar and a rubber bungee cord attached because I was doing this by myself, no help.