Hot Merc

[steve spears]

Over heating '04 150 XL EFI Saltwater (W/ 60 hrs total) Just replaced water pump assy, t/stats and still enjoy alarm sound. Pulled t/stats and seems to run cooler however right bank still hotter than left. Does the poppet valve have any effect on circulation at idle speed? I'm under the impression it does not. I have not checked this yet. Motor does circulate water well and telltale hole has strong stream. Please help!

 

[hkeiner]

Re: Hot Merc

If you hook up a water pressure gauge to your motor, you will probably troubleshoot the problem more effectively. The below attached guides answer some of your questions and may help you out troubleshooting your problem.

If the pressure levels look good at all RPMs, perhaps you are running the motor too lean causing the overheat.

http://www.diy-boat.com/index.php?option=com_content&task=view&id=151&Itemid=49

 

[oldrock]

Re: Hot Merc

No experience with your exact motor but my 50hp merc has similar issue. I've been forced to do alot of research on it to try to figure out what is wrong with my 01 motor. Seems there are alot of issues that could be going on. You are doing the normal stuff and I did those things too. Didn't fix my problem. ONe thing I have read about is the grommet on the water uptake. Apparently it can swell over time and cause a restriction in water flow to the upper motor area. I haven't tried checking mine because it would require alot of assembly work but you might want to look into that since they said it seemed to happen when motor is exposed to salt water.

GOod luck with your motor and be sure to post back if you find out what was the cause. My motor will run fine if I keep RPMs to about 4000 but the alarm goes off if I run it faster.