If the springs were installed and not tensioned you will hear more valve lash or tappet type noise than normal.
There was a post a few years ago of a fellow who tracked down a noisy valve train on his twin to a defective split cam gear tensioner spring. Posted several short video clips showing how he tracked down the noise by rotating the engine by hand with the valve cover off then removed each cam until the noise went away. Found the defective spring.
