mariner 15 hp help?

[Bryan_TX]

i have a cooling issue with a 15 horse mariner. i replaced the pump same results as before i replaced it so its pumping fine. it pisses fine at idle and just aboveidle but when i open it up it gets hot. i did pull the thermostat out of it. does it have to have a thermostat in it? i also found some grass on top of the water pump when i was troubleshooting last night. i opened the cover for the water jackets and could blow air through all passages but the tube from the discharge on the water pump the air was slower. icouldnt get good pressure on it though. any suggestions.
thanks
bryan

 

[Bryan_TX]

Re: mariner 15 hp help?

any one? im stumped.

 

[corm]

Re: mariner 15 hp help?

Hi,

I am wondering if the tell tale comes off the thermostat so it would be hot.
I think it has a 143 degree stat in it. Did you test the stat in a pan of water to see if it works?
I do not know if you can run the engine without the stat and have it cool correctly, maybe someone else does.

 

[Bryan_TX]

Re: mariner 15 hp help?

thanks for the reply. i took it out and it was pretty corroded. i only run this motor in saltwater. i am going to replace it and i also talked to a guy at work and he thinks that from my symptoms that maybe i have blown a head gasket.
thanks
bryan

 

[corm]

Re: mariner 15 hp help?

Hi,

If it is a two stroke it does not have a head gasket.
I don't know where the spots are that pool some water in that block.
It could be that some of the internal passageways are plugged. I also do not know if there is any solution that would dissolve any salt deposits that maybe blocking an internal passageway. I don't know much about running is saltwater except it corrodes the metal if you don't flush..
Did you pull off the back water jacket cover off to look around the cylinders?

 

[Bryan_TX]

Re: mariner 15 hp help?

pulling the covers is my next step i just cant get to it until this weekend. your right no head gasket. thought that would be a good fix though.i ordered all new gasket for the the cover plates and i am going to change those while cleaning. i flush that motor everytime i use it . i just cant figure out why this all started all of a sudden.
thanks
bryan