E120TLERC continuous warning horn

[jimbobcooter]

I have a 94 Evinrude E120TLERC. We were out on the lake today for about 4hrs. She ran great until we went to run home. We idled out of the cove we were in and then cranked her up to about 80-90% of WOT. After about maybe 3-5min a continuous alarm sounded. My brother was driving so I told him to shut it down immediately. He came to a safe stop and shut the engine off and the horn stopped. When I put the key back in the ignition and turned it to the on position the alarm sounded continuously again. When I pulled the cover the starboard side had a tacky liquid on it b/w the two plugs (not sure if it was oil or paint from the head).

After using the trolling motor to get back to the dock (~15-20 min) I tried starting the engine again. No alarm and water from tell tale. Shut it down Retrieved the trailer from another launch (~30-45 min). Decided to let it idle for a bit at the dock before leaving. No alarm and the port head seemed to get hotter than the starboard. I let it idle for a good 5 min with no alarm. I let it continue to idle while I backed the trailer in. With still no issue I took it for a quick spin to get her up to speed. Maybe a 5 min ride with no alarm or noticeable change in performance.

I am thinking this is an overheating issue, but I would think that it would have repeated. Could it have just been some trash that was blocking the intake grate? When the alarm initially sounded we quickly raised the engine and there was nothing around the intake on the lower unit.

Note: Water pump was changed this past winter. Carb cleaning planned for this winter as I have had some coughing at idle. Oh and this debacle http://forums.iboats.com/forum/engin...120tlerc/page3

[Joe Reeves]

Since the engine did not loose power, it's unlikely that a fuel restriction existed that could trigger the constant alarm... and more likely that you did indeed encounter a overheat condition.

It's always possible that the lower unit picked up a plastic bag (or whatever) that closed off the water intake... and when the engine was shut down, especially if the engine was tilted for a look see... the bag would drop off before you could view it. Those things can drive one nuts!

I'd suggest you double check the condition of the water pump in order to avoid a disappointing future outing.... and to install a couple new thermostats to put your mind at ease pertaining to the uneven heat between the banks.

[tinhdauhcm1]

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[jimbobcooter]

Thanks for the response Joe. Thermostats were just replaced in the spring. Is there a good process for examining the entire cooling system to make sure I did not suck something up that is now lodged in the block somewhere?

Also, do I need to worry about head gaskets or re-torquing head bolts no that I have had an overheating issue? It is my understanding that things have to get pretty hot for the alarm to sound!

Again thanks for the advice!

[Joe Reeves]

It wouldn't hurt to check the head bolt torque but if you shut the engine down shortly after the alarm sounded, it's unlikely any harm was done as the alarm sounds off before any damage can occur.

[jimbobcooter]

I finally got to the t-stats. I found that the spring on the starboard side (the hotter of the two) was bent and deformed when compared to the port side. I am going to be replacing them both...but wanted to see if that could be the cause of my overheat?

I tested the t-stats suspended in a pot and both opened (there was a small rod that extended from one end), but neither closed once the water cooled. Sometime after taking them out of the water I was able to push the rod back down. Is typical operation?

Lastly, I found a small piece of debris (3cm x 2cm) in the spring behind the diaphragm on the port/cooler side. While everything is apart I was going to drop the lower unit and run some water through the cooling system. Would it be best to flush from the bottom up or the top down or both?

Thanks for all the help!

[Joe Reeves]

The rod, (plunger) of the thermostat is pushed back into place (seated) by the return spring. If corrosion has built up in the plunger slide, that would cause a sticking sensation.

Best to run water both ways when flushing.