87 Mercury 150HP XR2 Water Temperature

[2dlking]

How hot should the water coming out the engine be on an 87 Mercury 150HP XR2?

 

[chiro757]

Re: 87 Mercury 150HP XR2 Water Temperature

water should never be hot on any motor. i have smaller mercury that ran hot. hot to the point where you can burn your hand in about 1-2 seconds. i needed a new thermostat. im not a mechanic but thought i would give you the information i have learned. the thermostat was 10 bucks and easily to install. hope you get some other replys as well.. good luck and good boating.

 

[Silvertip]

Re: 87 Mercury 150HP XR2 Water Temperature

You may feel a slight change in water temp at the tell-tale as the thermostat cycles open and closed but you would never burn yourself or even come close to it. In fact it could best be described as barely luke warm.

 

[2dlking]

Re: 87 Mercury 150HP XR2 Water Temperature

How hot should the water coming out the engine be on an 87 Mercury 150HP XR2?

It is very hot to the touch and I getting both a intermidete tone and solid tone. What could the problem be?

 

[gss036]

Re: 87 Mercury 150HP XR2 Water Temperature

Are you referring to the warning horns? Intermentant is oil, solid beeeeeeeeeeeeeeeeeeep is temperature.
You need to figure out what your problem is before to ruin the engine. Check the thermostats, they open at 143 degrees. At what RPMS are you getting the alarms?

 

[2dlking]

Re: 87 Mercury 150HP XR2 Water Temperature

Are you referring to the warning horns? Intermentant is oil, solid beeeeeeeeeeeeeeeeeeep is temperature.
You need to figure out what your problem is before to ruin the engine. Check the thermostats, they open at 143 degrees. At what RPMS are you getting the alarms?

The sounds are coming a higher rmps and it will stop and idiling rmps

 

[andy6374]

Re: 87 Mercury 150HP XR2 Water Temperature

The situation you describe can be one of two things.

1.) Sounds like the poppet isn't opening. You'll need to pull the pressure relief valve housing cover and check out all the components. And you mine as well replace it all while you've got the bolts out. It's located right under the switchboxes.

2.) Or the hub on your impeller could be slightly spun to the point where it grips the impeller at lower RPMs and not at high RPMs.


Do you have a water pressure gauge?

 

[Silvertip]

Re: 87 Mercury 150HP XR2 Water Temperature

The intermittent beeps indicate an oil related problem. Lack of oil can cause an overheat condition hence the two different tones. As was pointed out, the thermostat and poppet valve (pressure relief valve) could also be causing the overheat condition. Because there is oil in the tank does not mean it's being delivered to the engine. I would not run the engine except for diagnostic purposes until both issues are thoroughly checked and corrected. If the water pump impeller has not been replaced in the last couple of years, that should be done as well.