60hp 2004 mercury outboard 4stroke efi overheating

[diesel78]

I have a 2004 mercury 4stroke 60hp outboard and when i drive it over 3500rpms the overheat buzzer goes off and then I idle it back down and its fine.

I have replaced the water impeller and gaskets, and taken out the thermostat..I live in fl so don't really need to worry bout having it in.

I show no water pressure on my gauge at the instrument panel but the motor does pee out water at idle and while running.

I heard of a potter valve maybe being the issue but I'm thinking mine don't have one. I couldn't find one on the engine.

I'm at my wits end trying to figure out the problem with this motor. any help would be greatly appreciated.

This is the first time having any issues with this motor. I've had the boat for 3 years.

 

[jhcreech]

Re: 60hp 2004 mercury outboard 4stroke efi overheating

have you verified a overheat condition exist, when the alarm goes off shoot the temp sen with a infared thermometer, the temp should be 170-180 degrees F, with the engine running loosen the t-stat housing bolts and see if water is circulating, do u flush your motor after each use,could be bulid up of corrosion in the water jackets, also check the connections to the temp sensor possible corrosion, good luck and let us know of your findings.

 

[er-e-is]

Re: 60hp 2004 mercury outboard 4stroke efi overheating

I have a 2005 60HP EFI 4 stroke and had a overheating problem. It turned out to be the t-stat, mine had a 120 deg F stat. My Smartcraft alarm would go off at 172-174 deg F. New stat solved my problem. Sounds like you might have a circulation or sensor problem.

 

[diesel78]

Re: 60hp 2004 mercury outboard 4stroke efi overheating

Ya I flush religiously. No I did not confirm the overheat problem with a gun. I guess that would be my next step. I have no thermostat in there so I know it can't be that. Can new impellers be faulty and not work at 100%.

 

[er-e-is]

Re: 60hp 2004 mercury outboard 4stroke efi overheating

When I ran mine without a t-stat it caused condensation inside the motor and caused the motor oil to turn milky. I run in a lot colder water than you do though (65 deg F)