I have an irrigation system that's about 7 years old. I started to notice that some of my sprinkers' (MP Rotators) are either not rotating or doing so at an extremely slow rate. I've done several steps in attempting to resolve the problem but with no success. Hoping someone has further guidance for me.

Steps I've taken:

First I cleaned each filter within the spray heads to ensure there was no clog. No luck. Then I bought a pressure gauge and discovered that my spray heads are anywhere from 60 to 80 psi. The spray bodies are basic Orbitz brand, so I started replacing them with pressure regulating spray bodies from Hunter. I've verified the pressure is now around 38 psi.

Despite all this, the rotation problem persists. I've run out of ideas. I still haven't replaced all the spray bodies yet, so wasn't sure if I need to get an entire zone on pressure regulated spray bodies before I see a change?

Update: Adding photos. Also realized the old spray body isn't Orbitz but...I think Rainbird?

Old and new spray bodies

Old Spray Body New Spray Body

Filter and in the ground

MP Rotator Spray nozzle and body

In action. Streams look good, they just aren't rotating.

Nozzel doing nozzel things

  • Could you post a picture so I can ensure I will leave you a proper answer. I think I have a idea to fix your issue. Thank you
    – Ljk2000
    Mar 6, 2018 at 20:15
  • Added photos. Also realized the old spray bodies aren't orbitz. Hard to read the writing on the them...but I think they are rainbird.
    – Ifrit
    Mar 6, 2018 at 20:51
  • thank you, I will be answering to my best when I get home from work in two hours.
    – Ljk2000
    Mar 6, 2018 at 20:56
  • These were not what I thought they would be. The computer I have at school does not show the pictures, which is why I waited till now. And unfortunately I can not help with these. I do hope that somebody else will know how to help you out, sorry!
    – Ljk2000
    Mar 6, 2018 at 23:42
  • 1
    What is your water source? What is your filtration system like? Are you on city water or your own well? Your problem are the salts in your water. Or even sand in a shallow well. Clogs up all those holes. Contact Rainbird. They'll give you instructions to clean and maintain your heads or even recommend NEW heads.
    – stormy
    Mar 7, 2018 at 1:32

2 Answers 2


Hunter Industries has a trouble shooting article for MP Rotators that are no longer rotating. However even after following that, the problem still persisted. In the end, buying brand new nozzles seems to have done the trick. Not sure if my original nozzles were too old or too worn out from the years of high pressure. Or perhaps a little of both.


I have several zones of the hunter MP mini rotors. I’ve had good luck with them for the most part, but the MP3000 in particular, with the blue heads, have been horrible. I’ve purchased replacements now 3 times for the 2 zones that use them. Sometimes they work for a while, then freeze or rotate super duper slow, and some of barely rotate right when new. I’ve tried everything recommended, with pressure regulated 6 inch pop up’s, and these things have destroyed my grass this hot summer.

A few days ago I discovered they make a 3500 now, and bought 10 of them to try. I installed 8 of them today and they appear pretty good, will give them some time. Otherwise I think I’m gonna have some major diffing and rework some zones to actual geared spray rotors.

Sorry I couldn’t be more help.


  • Four years later and I'm still having issues. Replaced everything too with top of the line pressure compensating parts. I think the culprit is my very hard water. I think it gunks up the spray heads. Once I clean them a bit, they go back to normal for few months.
    – Ifrit
    Aug 13, 2022 at 2:04

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