adjuster on the shock is the rebound adjuster

adjuster on the rezzie is compresion adjustment.   only on 87-92 lt250r shocks. 

do what they sound like.  rebound is how fast it rebounds after a hit.  and compresion is how stiff it is on the compresion stroke. 

if the shock has never been serviced, you probably won't feel a differance in the adjustments.  oil breaks down, passages become clogged.