My friend has a 5hp force that overheats when he opens up the throttle but is fine at low throttle. The pee hole is pissing water and the pump appears to be ok. The engine gets so hot it actually steams. A mechanic checked it and said everything was fine and to just add more oil to the gas.<br /><br />Any thoughts what could cause this problem?<br /><br />Thanks
<br /><br />I think there is parts of a broken impeller stuck somewhere. Or something else, like salt build up.