ok guys i got the heating problem fix it was clog up risere. put new one and flush exchanger no more over heating thanks to you all. one more problem the boat have twin 470, two fuel tanks, trhew tanks have two turn off valves. what i notice when ever i put gas and take the boat out one tank is almost empty while the other one is not in use. today it was running then it just died. one tank said half the other one said empty.i dont know it was running like that for days did not turn the valve .why the engin is not getting any gas from the almost full tank. ok to cut it short both motor cut off at once. thanks for any help