25hp Johnson overheating

[ratkinson]

I suspected that my engine was running hot so I took it out and checked the surface temp of the power head after running WOT. My gun read 200'F. The manual says over 165'F is a problem so there you are. I have already replaced the impeller and thormo so now what? I noticed that there is water pumping out of two holes just above the lower gear unit,is that normal. Any suggestions would be appreciated.

 

[merc350]

Re: 25hp Johnson overheating

i have had the same problem, new impellor, new waterpump housing, pumps water, but still overheated badly.
turned out the thermostat was corroded closed, and the block and head were full of silt.
its a 25 hp johnson.
turned out i bought a new head, thermostat and gaskets. .

 

[tashasdaddy]

Re: 25hp Johnson overheating

go back and make sure the water tube is connected, and you could have crimped the gasket the water tube goes into, restricting water flow, also that the key stayed in the impeller.