Merc XR2 150 overheating

" The motor stays cool below 2

" The motor stays cool below 2000 rpms but when I hammer on it, it will eventually get hot and I can see steam rolling off the pee stream. These are the things that I have already done. Put new water pump everything on it, impeller,housing,cup, plate,& gaskets.New pressure relief valve, Head gaskets,new thermostats I've ran it without the thermostats in it nothing changes. It will only give me 15 to 17 psi at wot. And barely reads 1 psi at idle. I've talked with several techs. around this area, does anyone have suggestions, I have ran out. Thanks "

"Ronnie,

If you are certain

"Ronnie,

If you are certain that you installed the water pump properly, there must be a leak somewhere in the cooling system. It could be a problem with the water tube itself, a bad gasket in the exhaust system, or even a bad gasket at the base of the powerhead.

When you replaced the water pump, you should have checked the cooling system for obstructions or leaks before replacing the lower unit. Sometimes debris can accumulate in the water tube and other places. Frequently, when an impeller breaks up, pieces of the blades will be forced up through the water tube. This can be a difficult problem to deal with. Back flushing can help if you are lucky, but usually you just have to take everything apart to find the pieces.

When the lower unit is removed you can attatch a hose directly to the water tube and run water through the cooling system. You can even run the engine this way and look for hot spots, which might help find the problem. If water does not run through freely when you do this, you know for sure that there is a blockage somewhere.

"