Not really. But take it apart and understand how it works, then it's easy to get it all right. Basically, you install the outer sleeve of the tensioner, then push the piston with the "ratchet" grooves in, and then press the spring in to tighten it up. So, it adjusts automatically when you push the spring down.
By the way, pushing the spring in and starting the threads on the tensioner cap can be fun. You can make a little tool from an old bolt that you can jam in the tensioner cap and wedge against the air pump, to get leverage to hold the spring in place. Grind a couple flats on the bolt so you can turn it with a wrench while it holds the spring/cap in place. You'll see what I mean when you look it over.

DG