Mercury 150 XR6 overheating questions

[Archemil]

I have a 2001 150 Xr6 carb that does not have that many hours on it, but this year it has developed a overheating problem(alarm goes off). I do not have a water pressure or temp gauge. I might install one after this. I first noticed this when the alarm went off with a steady beep. But I have noticed the beeping noise like it was just barely going off, especially when I trimmed the motor it would chirp very little.

I am checking the T stats and @ 145 - 150 Degrees they barely open and will open more around 200 degree? Is that normal or should they open all the way @ 150?

 

[Archemil]

Re: Mercury 150 XR6 overheating questions

I dropped the lower unit and fixed the water pump with a kit and the overheating issue went away, warm water from the tell tale at any RPM above idle. The only time i get HOT water now is when I idle... go figure. The alarm does not go off so I am not overly worried, just want to know if this is normal. What I mean by hot water is you can only hold your hand in the stream for only a second.

 

[BassFish]

Re: Mercury 150 XR6 overheating questions

T-stats are fairly cheap so I would just replace them especially if they are original (9 years old). They should be 143 degree t-stats. Hope this helps.

 

[Archemil]

Re: Mercury 150 XR6 overheating questions

I changed the T stats before I fixed the water pump and I have the same issue at idle. More info :

When I pulled the water pump the problem was easy to see, the gaskets were broken and looked like pieces may have been sucked into the system. Could those pieces be stuck some where causing the overheating @ idle?

 

[hkeiner]

Re: Mercury 150 XR6 overheating questions

If you do install a water pressure gauge, the below linked guide will help in narrowing down the problem.

http://forums.iboats.com/attachment.php?attachmentid=26806&d=1240515681

http://forums.iboats.com/attachment.php?attachmentid=26808&d=1240517707

 

[j_martin]

Re: Mercury 150 XR6 overheating questions

I changed the T stats before I fixed the water pump and I have the same issue at idle. More info :

When I pulled the water pump the problem was easy to see, the gaskets were broken and looked like pieces may have been sucked into the system. Could those pieces be stuck some where causing the overheating @ idle?

Yep. Water pressure gauge would verify high pressure before you tear into it. It would also verify low pressure, indicating something is still wrong with the water pump, delivery tube, or poppet valve.

hope it helps
John

 

[BassFish]

Re: Mercury 150 XR6 overheating questions

If you found the impeller in pieces there is a good chance that some of it was sucked up into the powerhead. You can back flush the engine which will sometimes remove the pieces.

To Back Flush:
1. Remove lower unit and t-stats
2. Place container (5 gallon bucket) under mid section
3. Put water hose into t-stat housing and flush with water

Do both sides and the water should drain into the container and if you remove anything from the engine you will see it in the container.

Another useful tool for overheat issues is an infrared thermometer. They are cheap at harbor freight but work well. You can use it to determine hot spots on the engine.

 

[Archemil]

Re: Mercury 150 XR6 overheating questions

Good ideas, thanks!