metlmatt, I know it as an impact sprinkler; the problem you describe can be fixed temporarily by cleaning and lubricating all the moving parts. (What would we do without "WD 40"?). The permanent fix would be to replace the whole sprinkler or if that is too problematic, just the innards. You will need to buy an exact replacement and a special tool to replace the internal unit.

My system was working fine until last week. I have very little flow from all sprinklers on one circuit, all other circuits are fine. I ran the system for 2 hours to check for leaks, but no puddles appeared. Is this a valve solinoid problem, or maybe a diaphram? I think the entire system is Toro, but I just bought the home. Thanks in advance...tony

They some times get grit or something that is interfering with the rotation.

Here is a link that might be useful: help_site

Hi All,

NotFarmers, the following may be more applicable to your case.

All the above and also check if your pressure has changed in your house or system. A pressure gauge that can be put on your hose bib or a system source can be be purchased at your hardware or garden store for very little (>$10). If you don't know your previous pressure. Find out the operating pressure for your sprinklers and see if they rate higher than the existing psi. Checking flow (gpm pr gph) by timing the filling of a 5 gal bucket from your system. Check the flow specification for the sprinklers you are using and compare against the flow from the source. Appears to me to be some type of sudden reduction of flow or change in pressure to your system. Trial and error always works best when proceeded by as much useful info as possible. That is why I appreciate these forums. Good luck and aloha.