No water flow at low RPM

[Kerwin Wellon]

Hi guys, I have a 2013 Yamaha 25hp 4 stroke. It pumps water out the pisser from quarter throttle to full throttle but not pumping at idle and low throttle. This results in over heating.
Any suggestions? Appreciate any help on this.

 

[mike_i]

When was the water pump replaced last? Does it happen with the boat in the water or the motor on muffs?

 

[Sea Rider]

Does the motor pees with a good water pressure at middle to max throttle ? How do you know the motor is overheating, does it have a temp sensor that triggers the slow mode, red light whatever ? What's the thermo condition, remove it and check if rusty, salted ? With motor On insert a plastic cannula, wire through the peeing port and poke it in-ot several times the deepest that will go, check if now pees much better at idle and low throttle than before.

Happy Boating​