200hp mariner over heat problems

[shawpdx1]

Have a 87 200hp mariner put new water pump in it will run fine until you get it up over 3000 RPM or to a plain and the over heat alarm goes off you can see discoloration on 1 cylinder possible clog ? cools right down at lower speeds its pumping water

 

[shawpdx1]

Re: 200hp mariner over heat problems

not expecting a diagnosis just I realize would need to look at it. just if anyone has had this problem and suggestions on what to look at for possible cause

thanks

 

[j_martin]

Re: 200hp mariner over heat problems

If you don't have a water pressure gauge, get one and put it on. It will tell you more about the cooling system than the temp gauge.

Any possible solution proffered without water pressure data would be a scientific wild ****d guess.

hope it helps
John

 

[CaptainHook]

Re: 200hp mariner over heat problems

It is possible to be pumping water but still be in need of an impeller. The impeller has multiple vanes on it and if one or two are chewed up it will still pump. Just not as efficiently as it should. It may move enough water to keep you cool at low rpm but not when under a real load.

i would check it out!

 

[Barnacle_Bill]

Re: 200hp mariner over heat problems

Rebuild your poppet valve.

 

[j_martin]

Re: 200hp mariner over heat problems

Any more SWAG system solutions?