250 Merc 4 stroke Pro XS PSI issues

[DChiWildcats]

My 250 four stroke pro xs is having low psi and overheat issues and can’t figure out why. Impeller has been recently replaced but I notice that when I sit at idle even when I first launch my smart gauge shows the temp consistently going up to 150-160-170. I have to engage the throttle to get the temp back down to 140 constantly. Engine is pissing the entire time.

When cruising at 4500 rpm psi shows between 7 and 11 usually. If wide open it sometimes goes up to 17-20 but a lot of times its 13. Get off pad, temp starts rising. Any ideas? Jack plate usually down. Boat id a 520 L Ranger.

[EuropeanAM]

If you would, please be sure to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

Anytime you are having cooling or water pressure problems, you should ALWAYS, ALWAYS start AT THE SOURCE: The Water Pump.

Make sure you have a new impeller and gaskets (at a minimum). Better yet, complete kit (may not need the housing so a complete repair kit without the housing will likely suffice).

Thermostat testing/inspection is part of the Annual Maintenance.

[unpaulie]

Had same issue on brand new motor. It was missing 2 o rings from the build.