The R-50 is an internal impact sprinkler. This means that there are two small stainless steel balls that act as the drive mechanism.
To increase the arc - Keep in mind that the sprinkler is preset to approximately 180°. Pull up on the stem, slide the vandal collar out of its groove. Push down on the nozzle slightly, and rotate the nozzle to the right (clockwise). The arc will be increased by the amount the nozzle is turned. For example, if the arc was previously set for 180°, and it was turned 90° while the nozzle was pushed down, the sprinkler will now have an arc of 270°. Be sure to replace the vandal collar when finished.
To decrease the arc - Pull up on the stem, slide the vandal collar out of its groove. Push down on the nozzle slightly, and rotate the nozzle to the left (counter-clockwise). The arc will now be decreased by the amount it is turned. Be sure to replace the vandal collar when finished.
To change the arc to a full circle - Remove the internal assembly from its case. Slide the vandal collar out of its groove, and rotate the nozzle to the right (clockwise) until a strong resistance is felt. It will feel as though it is locked in place. Return the vandal collar to its groove. Rotate the nozzle to the right (clockwise), there should be no resistance felt in the 360° turn.
Stalling/fast rotation - Be sure that the adjustable bypass at the bottom of the internal assembly is set to match the nozzle that is installed. If the bypass is set too high, the drive assembly will flood and stall. If set too low, there will not be sufficient water and this can also cause the sprinkler to stall.
Cap to body leaks - You might encounter cap to body leaks on some older units. To resolve this, we have tightened the specs on the wiper seal and also added additional spring support around the wiper seal.