Quote Originally Posted by pat656 View Post
I have a 2006 Moomba Outback direct drive with 100hrs and it has a bad overheating problem.
The engine kept reaching 190 degrees and went into the protection mode where you can only idle until it gets below 180.
I had the impeller and thermostat replaced and i took off every water hose and inspected them for leaves/twigs etc since we spend a lot of time in the river.
We went back out and it still ran at 180 degrees and cut off many times at 190.
Then after a full day on the lake we parked the boat at the dock and had dinner. After about an hour we tried to start the boat and now it wont even start. We had to be towed to out trailer.

What might be causing this problem?
Did you check the transmision cooler? Sometimes they get packed with debris and restrict water flow through the system. Take the 1 1/4" hoses off each end of the cooler and flush from the top (outlet end) of the cooler.

I suspect your no-start issue may be vapor lock ... the fuel has vaporized in the system, probably between the tank and fuel pump and the engine will probably start once the fuel turns back to liquid.