Timing belt wiggles

Installed new 2300 engine and the timing belt looks like it is going to run off the aux and cam pulleys when running. I have changed the belt tensioner, the cam gear and the belt still moves. The next thing I am going to change is the belt. The belt 4 years old. Has anyone had this problem?

Thanks
TC65

The belt was the problem. Using a Gates racing belt which is about 5 years old. It had thin places like it had stretched.
Put a new one and it runs perfect.

Thanks

TC65

always mark rotation on teardown

Thanks Dave I will remember that