Hey all, I have a 1999 27 Baja Boss with a 509 mag And M3sc Procharger approx 750 hp.

The problem is, I have a Imco -2 shortie with low water pick-up. I was out and got into some shallow water and sucked up alot of sand. It immediately over heated. I pulled water pump and it was toasted, 2 fins were tore off and lodged in the housing.

I pulled hoses and rinsed also pulled plugs on side of block, flushed oil cooler and inner cooler, and Still overheating. Is it possible that the thermostat could have sit in it?

What else can i do? Thank You.

backflushm and open every hoses you can after to make sure it flows everywhere...

pull the motor b4 you toaste it,,the sand is probably stuck in the water passages around the cylinders.you may get away wit hpulling the freeze plugs..i would try pulling the 2 freeze plugs on the front of the block and back flush it like suggested.

Can i get to the freeze plugs without pulling the motor? The boat idles fine and does not over heat at low rps, The faster i go the hotter it gets. And then cools off fairly quick. I checked motor with heat gun and all seemed normal on hose. But when i put it in the water under a load it runs hot ...

Did you replace the impeller and the housing? If not, replace the impeller housing as well.

Yes i replaced both.

Check for a restriction on the inlet side of the cooling system, be carefull running hot usually the engine is a lot hotter than the guage reads especially if it overheated quickly. I would be concerned about the rings & head gaskets, Mr fixxall has a good point about pulling the engine. I would rather be safe than sorry with a blower engine, unfortunately I speak from experience in that regard. My .02 Randy

where the problem lies is when the water goes through the tiny holes in the head gaskets,thats where the problem starts,the water cant get through the little holes fast enough and the water starts to boil in the block..its really hard to get sand out of the block ,,it usually piles up in the corners of 1,7,2,8. if you could remove the freeze plugs on the front of the block and reverse flush through the thermostat housiing with the thermostat removed would be your best bet..just crack the garden hose a little bit,,you dont need 40--50 psi going theough their to blow or seep past the head gaskets.

You've still got sand stuck in there somewhere. You may have to pull the heads to get it out of the block.

Ok thanks, I was hoping it would be something fairly simple. I will pull freeze plugs and thermo and start sorting it out. Thanks for all your help.