1982 Merc 70 hp 3 cyl only pumping water out in gear and med to high rpm levels

[nxgncav02]

Help Please! I have already replaced the impeller and blown compressed air through the tubes but I only seem to have water coming out when I put it in gear and give it some gas once I bring it back down to idle the water stops. my local dealership wants me to bring it in of course anything I can try before going that route?

 

[pbgeneral]

Re: 1982 Merc 70 hp 3 cyl only pumping water out in gear and med to high rpm levels

Have you checked your Thermostat?

 

[nxgncav02]

Re: 1982 Merc 70 hp 3 cyl only pumping water out in gear and med to high rpm levels

I would if I could find it I asked the dealership over the phone and they said it has one but they couldnt find it in they're parts break down