cooling help

[CDJ31]

Hey Guys,<br />maybe someone can help me. due to the war on terrorism my boats been sitting for a few yrs.<br />I now have it cleaned and ready to go, my mechanic tuned my 1986 mercury i/o 140 up and it kind of runs good. Heres my problem, my temperature gauge red lines. my cooling system is running well because i have the ears attached and i can see the water being exhausted out of the lower unit, but the gauge red line. I opened the thermostat housing and noticed rust particles in between the sping of the thermostat I suspect that the rust particles are preventing the thermostat from functioning properly. I would appriciate any advice that helps clean out the cooling system of the rust particles.

 

[rybad]

Re: cooling help

Your best bet will be to run the engine normally (not on muffs). When you winterize, you can put some oil in the anti-freeze to help prevent corrosion in the winter.<br /><br />In any event, obviously, change the thermostat, but make sure you are not overheating.. check you water temp sensor too, it could be bad if your not overheating.

 

[Boatin Bob]

Re: cooling help

How long does it take for the gauge to redline, you could try running it without the t-stat in to see if thats the cause.

 

[cobra 3.0]

Re: cooling help

If you check my post on "overheating" It will help you. I changed my thermostat, impeller, and temp sending unit and I still have your problem. Mine works well on the muffs too.<br /><br />It was suggested that I also change the impeller housing. So I now ordered a complete impeller kit with a new plastic housing. I will see what this does.

 

[KRS]

Re: cooling help

Do try pulling the thermostat, and running that at the lake or with the muffs, see if redline returns. If not, probably bad thermostat.<br /><br />As for the antifreeze comment... I am assuming that you have a seawater system, and no antifreeze, so putting oil in won't help.<br /><br />Always flush system when you get home really really well.<br /><br />Water pump drive belt at proper tension?<br /><br />Good luck.