Merc 850 cooling system

[jjarrow]

I have a 1977 merc 850 with a jet pump, I am a novice to the outboard world so i need some help and have questions. I have inststalled a new water pump and not much water comes out of the weep/pee hole, but gushes out of the exhaust ports or the two holes on the back of the drive shaft housing, How does the cooling system work and where does the water go after it comes through the water pump, the mercury manual shows a general schematic as to where it goes but does not describe in detail. It starts like a champ and runs like a champ but i do not want to run it too long for fear of getting it to hot. From what i have described is everthing ok.
Thanks jeff

 

[SpinnerBait_Nut]

Re: Merc 850 cooling system

jjarrow or Jeff, welcome to iboats.
Let's get this up to the reapair forum for your answers.

 

[Scaaty]

Re: Merc 850 cooling system

Clean it out with a piece of wire..it cloogs up with junk (sand/silt) after awhile..try that first

 

[jjarrow]

Re: Merc 850 cooling system

Thanks for the tip on the weep hole, Now how does the water system work. Is the cooling water supposed to come out of the exhaust holes?
Thanks
Jeff

 

[jebeebe]

Re: Merc 850 cooling system

It almost sounds like you didn't get the water tube in the power head. The water should go through the power head and out the exaust around the prop. It is normal for some water to come out the ports below the powerhead, but I wouldn't think it should gush out. More like splutter some water. If there isn't water passing through the block it would steam pretty quickly and get hot. I would tear down and recheck. Too important to run that way...................Jerry

 

[jjarrow]

Re: Merc 850 cooling system

Jerry, Thanks for the advice, I took the jet pump off and took the water pump apart, I found a pice of plastic in the pump tube that may have been blocking the flow, It came from the plastic guide for the water tube, Hopefully that will fix my problems.
Thanks again!!