85 Comp TS6m stalling then will not start

Recently had this issue with the Supra, it will start right up when cold. Idles fine right after start up. Even runs normally for a while (towed two skiers yesterday with no problem). Then when hot it will stall at low RPM and will not start back up. Engine feels way too hot even though the gauge reads 160 (not sure if it is functioning properly now...). When i pull the flame arrestor off the choke plate is wide open and more often than not the carb barrels look steamy or smokey. I am guessing the impeller needs to be replaced, but I want to make sure there isnt anything more serious happening.

When I tried to start it back up there would be fuel pooring in to the carb after i stop cranking. I originally thought it was float or needle issues, but now i think its the engine getting so hot that the fuel starts to boil in the fuel bowl, which messes with the float level. After a couple seconds the fuel will stop pouring into the carb. I have only experienced this a couple times and only ran it to see if it has been fixed. Dont want to run it too much more if there are more serious problems, and certainly not until i replace the impeller.

Any ideas on what this could be other than the impeller? or has anybody experienced symptoms like this before? the boat was running perfectly before these issues.

When you stop the engine the coolant flow also stops . The engine will heat up because of no coolant . This is called a hot soak . Its normal . You can shoot the thermostat housing with a Infrared Thermometer gun to check the real temp. It sounds more like you need a carb overhaul. Float level too high, float needle not holding or power valve leaking.