overheating

[Bean]

OK bear with me. Not a mechanic. 2016 R3 300hp overheated today on the lake. Took it home and checked impeller. Brand new as suspected. Greased, replaced. Put a hose on the flush line. Ran great stayed around 160 degrees. Water coming out where it should be and the water vents so I'm thinking no blockage. Must be raw water issue. Tried muffs (to simulate lake) and no water coming out-temp rose quickly.
Does the raw water pump sound like the issue? Do these things fail? Can I take cover off the pump and see if the impeller is turning on a quick crank? Belt is fine and is turning. Thanks for the help.

[stifflkd]

If you put a hose at the flush port then the water is feeding the impeller similar to running muffs, although you can argue you may be getting better flow with the flush port. It sounds like there is blockage between the intake at the outdrive and your impeller. If you turn water on at the flush port without running the engine do you see water coming out of the outdrives intake? The impeller will basically block off the water if it is not spinning and divert the flow back out the outdrives intake.

[Bean]

I'll check when I'm back at the lake. Thanks