my buddy just bought a 2001 28 active thunder w/ 500 efi yesterday, we put it in the water today and it overheats, at idle it runs 170 and get on plane it climbs up over 220 and we shut it down, put a new impeller in it and took the t stat clear out to try it and no luck. at the sea strainer the water flow looks to be way to low as the strainer does not even fill up at all with water, it comes in and drains through as fast as it come in. shouldnt it fill the strainer full when running. we do have water coming out the exhaust but still overheats. the boat was last run 3 weeks ago and no problems then, there was alot of brown muck coming up in the water the day we went to pick it up and loaded it. something pluged maybe??

any help would great thanks Rick

water coming out the exhaust? take the output of the water leaving the enigne and attach a hose there and BACK flush...back flush each of the coolers...silt and crap will plug them w/o damage to the pump.

Thanks joe

you can aslo run the boat for a bit with the water off the exhaust ...this will alow you to see if there is h20 in the exhaust...hope not....don't run it too long or you'll blue the pipes.

due to the fact that we have a good flow of water coming out the exhaust tips, could it be a deffictive guage or sender, does the buzzer activate from the guage itself. we did a back flush and all seems to be flowing fine and no dabre came out.

The alarm activates from a separate sender near the Tstat housing. It should have gone off by 200*

several thing come to mind check the oil cooler for old inpeller pieces from earlyer water pump jobs and if its a salt water boat we have seen the hose where it comes thrue the transome shield get pinched down from corrosion and get very limited water flow.

i have never had a sea strainer on any of my boats , when at idle should the flow of water coming into the strainer keep the strainer full of water because ours does not fill at all it drains as fast as it comes in. thanks