I usually set it so about 1 coil of spring shows.

Previous thread with illustrations.

https://talk.newagtalk.com/forums/thread-view.asp?tid=424239

Pay special attention to Maxx Catt's advice from the thread in blue below.

One thing to check if you take it apart is the flatness of the flat bar the nose sprocket and tensioner spring attach to. If it is not flat excessive bowing will cause it to will hang up in the block.Also if the flat bar has been tweaked from flat it will change the alignment of the sprocket which will cause the chain to run over it at an angle and it won't line up correctly with the top sprocket.

Hopefully it makes sense after seeing it illustrated.

Just looking at it does not always seem self evident if your not familiar with the setup.