Onga js120. Wont hold pressure

based on info provided the motor is bad. Call mastercraft for more help. It may not be deigned for lawn irrigation.

It sounds like a pressure switch problem. Check that your tank pressure is at two psi below your cut-in pressure. If it is correct, then I suggest replacing the press switch.

There will be water come out of the heads for a few min after they shut off to bleed the pressure off there is no way to stop it you might turn your system timer down a little

If manual override works, and dial rotates on time each 24-hours, then worn trippers are suspect.
http://waterheatertimer.org/Intermatic-trippers-and-parts.html#sprinkler
http://waterheatertimer.org/How-to-troubleshoot-Intermatic-timer.html

Upvote the help.
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Set or replace the regulator it normaly at the base of pressure tank,,

The pump is putting out too much water for the sprinkler.
You can raise the pump shut off pressure at the switch until it is higher than the pressure that the pump runs at with the sprinkler operating. You should have a surge tank connected to the system to give the pump time to balance with the sprinkler.
You can use more water with the sprinkler. This could mean adding another sprinkler or increasing the nozzle size of the existing sprinkler.

Hi,

Here is a tip about how to get parts for your traveling lawn sprinkler and also a great article about how traveling lawn sprinklers work.

Traveling Lawn Sprinklers

heatman101

Sounds like the bladder is gone or inproper air pressure in water storage tank.

Bladder goes bad check it out with step 1
1-
One way to check for sure with everything hooked up. The air valve on top of the tank if pressed you will get water out of the valve which should be only air. This will let you know it should replaced.

If Tank bladder is low in air and not water coming out.

2-If it checks ok put an air gauge to tank to check the air pressure, with a standard 40 gal tank you will have 28 psi of air in tank for it to function properly.

a number of possibilities like insufficient pressure in the bell or pressure leak 'or pump motor dying
but i'd be looking at a warranty claim

I don't know what is your system set up. However, the system set up should be the following;
1. Your 1-1/2HP sprinkler pump must be installed at
a fix location nearest the water source. (Complete
with power and plumbing lines.)
2. At the end of the suction line is a vertical check
valve with strainer.
3. The suction pipeline must be connected to the
suction port of the pump.
4. At the discharge port, a flow control valve tee must
be installed. The flow control valve tee top is
covered with a plug, which serves as the priming
port when opened.
5. After the flow control valve, connect a short nipple
so that you can put a gate valve to stop the water
flow or allow the water to flow. You may connect
a pressure tank at this point or you may connect
the pressure hose going to the sprinkler.
6. To prime the pump, open the plug at the flow
control top. Fill it full with water, replace the
priming port plug.
7. Turn the flow control valve to full closed position.
8. From full close position, switch the power on.
9. The pump now run on and off due the pressure
switch setting. Slowly open the flow control valve
such that the water pressure remains steady.
10. Take note of the pressure.
11. Shut the power off, and connect the sprinkler
pump hose.
12. Put the power back on, and allow the pump to
run with the sprinkler.

Under this set up, you can run the sprinklers when your pump is running. Hope this will solve problem.