Question
I recently bought two Toro 570 adjustable sprinkler heads to cover some new grass that I put in.  I assume you adjust the pattern by turning the very top; however I can only turn it a little before the entire top blows off and I get a geyser in the backyard.  What am I doing wrong?

Answer
If they are the variable arc nozzle, then you adjust them by turning the area just below the top of the nozzle.  You may need two hands to do this.  You turn it one way and it increases the pattern, opposite to reduce it.  Try doing it with the water off, or with the nozzle remove just to practice.