Sprinkler tuning

[Mazin]

I would just replace the heads and be done in 20 min. They probably are stripped, it's happens over time. They screw off and are not very expensive.

[DEAGLER]

I would just replace the heads and be done in 20 min. They probably are stripped, it's happens over time. They screw off and are not very expensive.

Yep. Most likely 1/2 inch. Dig them out and unscrew it. Try not to get dirt inside the riser.

[SideShow Bob]

Yep, replacement as mentioned.
When you dig them up, don't be lazy, dig around them enough to prevent dirt falling back into the supply line below. If you don't keep dirt out, the new head will clog up the screens inside as soon as you turn the water back on.
Also, test the new heads before re-burying them. It is no fun having to dig them back up due to a leak or clogging due to dirt getting in the line.

ask me how I know.........