well when i first got the boat i was breaking the motor in and it kept overheating!!! i then discovered tht the water pickup(inside the rudder) was full of metal shavings, which is why it was overheating!! no water at all was circulating!! i would say that this was hard on the piston and sleeve to overheat that much during break-in!! i will start over with a new motor and keep check on things better..