cruising the net i found this: https://www.youtube.com/watch?v=CacfmuSVk2s

it sounds similar to my noise and the owner says his nut was loose on the pulley. that might be what it is on my bike since the engine was changed. i did get the old engine from the PO and the pulley is not on it so he may have swapped it without the proper tools and didn't get the TQ right.