1996 Galaxie 2050 ultra boat with 350 and yamaha outdrive I/O

[kritter88]

The boat keeps running hot, I have replaced the impeller, thermostat, front water pump, sending unit and added a new water temp gauge. No water in the oil. Is it the heads or exhaust manifold. The boat has exhaust our the back

 

[triman]

Re: 1996 Galaxie 2050 ultra boat with 350 and yamaha outdrive I/O

Just after the raw water pump is an oil cooler. if this is partially blocked you won't get full flow. Find it, standing vetical on the starboard front side of the engine, disconnect hoses and back-wash it. May not be the problem but it eliminates another possible source.
Alternatively, has the long hose from the transom, along the port side of the engine up to the raw water pump collapsed?