5.7 GXi-A overheating

[Steve Nast]

New to this forum so please bear with me. I have a 2001 ChrisCraft with a 5.7 GXi-A red motor. I have change the impeller last year and just inspected it after overheating has started. It is fine no nicks or cracks etc. If I run the boat at 4000 rpm for more than 10 min it starts to overheat. Is there another impeller I am missing or one in the lower unit I need to check. I'm sure there is a post on this somewhere but was unable to locate it. Please advise or help with some info. Thanks

 

[Dakota47]

Re: 5.7 GXi-A overheating

most of the time the impeller LOOKS good, but should be replaced .. cheap & easy to do.

 

[Philster]

Re: 5.7 GXi-A overheating

t-stat needs replacing before continuing the investigation.

Then...

Check tube(s) coming in from drive. Corrosion can squeeze them down to nothing, and this shows up at higher RPM when more water flow is needed.