Merc 120 I/O coling

[HonestLou]

I have a 1983 Stingray with a 120 I/O. It was running a little warmer than it used to, so I canged the lower unit water pump. It will now run cooler, at idle 140 - 150 deg F, but runing hard the temp climbs to 180 - 200 deg F. Is this normal or is there a problem?<br /><br />thanks

 

[doman]

Re: Merc 120 I/O coling

180 theremostat in there so you are right where you should be ...please correct me if im worong<br /><br /><br />Dom

 

[tommays]

Re: Merc 120 I/O coling

it depends if you are raw water cooled it should stay around 160 max <br /><br />freshwater cooled( heat exchanger) would get about 180 - 200 max<br /><br />what was it in the past when it was ok there is something wrong if it is runing warmer than it use to<br /><br />tommays

 

[HonestLou]

Re: Merc 120 I/O coling

It seemed to run about 160 max and since I changed the lower unit water pump it runs hotter. I have not had it in the water for about two years so I changed the pump when I thought it was running too hot. It is cooled with external water (seawater), so I still thing it should run a little cooler. I am thinking I will change the thermostat and see if that will make a difference. I only changed the water pump, no gaskets or seals. Maybe there is air getting in the system displacing some of the water at high speed???

 

[Galloping Ghost]

Re: Merc 120 I/O coling

if it has been sitting - there is always a possibility that there is blockage somewhere - i have put clear hoses in the engine and watched the motor push the water through to see what it is doing - this is a really easy fast way to see if you have water coming in - if there is blockage, it could also be on the way out of the engine.

 

[itstim]

Re: Merc 120 I/O coling

so you put the clear hose at the end of the water travel system?

 

[tommays]

Re: Merc 120 I/O coling

i would recomend allways installing a compleat kit with seals and gaskets when going to all the trouble of removeing the drive its only a littel bit of money and you get piece of mind noing its 100%<br /><br />tommays