Small Engines (Lawn Mowers, etc.): John Deere STX38 drive belt installation, john deere stx38, lawn mower

Question
I recently acquired a John Deere 5-spd STX38 riding lawn mower.  It is over 10 years old.  The drive belt was worn, so I replaced it.  My question is:  How does one adjust the tension on the drive belt.  There is a tensioner and it is not self-adjusting.  In fact, there doesn't appear to be a clear method to doing it.  Any help and advice much appreciated.  Thanks.

Answer
Hi Todd,

The tensioner is usually self adjusting by a spring or by a threaded rod or bolt.  (Both of which may be missing.)  In some cases, the clutch will bring the belt into tension.  If the latter is the case and problem just started, the replacement belt may be too long.

Let me know how you make out.
Michael