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Discussion Starter · #1 ·
Let me start by saying that I replaced my thermostat's at the begining of the season.

Due to circumstatnces beyond my control, I had to leave my marina abrubtly and didn't get a chance to flush my engine with fresh water. I also haven't ran my boat for a month or so. I keep my engine tilted out of the water when docked. Last week the overheat alarm went off.

My question for everyone is does the salt water make the thermostats "stick" if the engine is in the upright position when not in use for an extended period of time (a month) due to the evaporation of salt water?

Was wondering if a product such as Salt-Away would help this? Also, how much is the Salt-Away kit?

Thanks much!
 

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you don't say what motor you have or when the motor overheats.

The thermostat only controls temperature at idle and low rpms.

There is what they call a poppet valve in your motor that controls cruise and high speed cooling. Some BOM/OMC models have springs on the thermostats that allow the water flow to lift the thermostats off their seats at cruise and high speed instaed of a separate valve port. I'd check that A month with the motor up shouldn't be a problem with salt issues
 

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Discussion Starter · #4 ·
I have a 1990 225 Johnson VRO.

It happens at about 3500-4000 RPM's.

Joe, you worked on my boat before. This alarm sounding has been a ghost in the machine since I got it. Thing is, since I put the thermostats in, the alarm hasn't sounded. This has been the first instance this season.
 

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If you put the garden hose to the motor and turn the water all the way on you should be able to hear the thermostats lifting off their seats.
 

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Is the motor acually overheating or is this an alarm issue? With the motor cover off which head is hot to the touch when this occurs?

There are two temp switches one on each head next to the thermostats that trigger the overheat alarm.

If you pull the single wires (one at a time)from the temp switches when this happens the horn should stop sounding. Grounding these wire leads to the motor, the alarm should sound with the key on. If these wires are bare of any insulation allowing them to touch ground, the horn will sound. If the horn still sounds with the leads off the temp switches, wiggling the harness and wires might help see if there is a wire shorting problem.

If the alarm stops when you disconnect the wire(s

Check the temp switches with an ohm meter. Cold and normal running there should be no reading from the bullet connector pin to the base of the switch or motor ground(open circuit). Above 170* the temp switches activate and you would see and ohm reading.

To test
Put them in a pan and heat the water checking resistance as you heat them up. There shouldn't be a reading until the water is above 170*

These motors normally run at 140-160* at idle an drop down lower at cruise speed.
 

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Discussion Starter · #8 ·
Thanks for the replies guys.

It seems to be the overheating alarm not oil alarm (long alarm followed by engine dropping into safe mode - maybe 1000 RPMs)

Personally, I don't believe the engine is overheating OR running hot. After this happened and I reset the alarm, I procceded to drive out to the horseshoe and fished for about 3-4 hours. Before I went back to dock, I primed the bulb and took the 11 mile ride back into Bidwell Creek without further incident.

Other things I did in the offseason BESIDES the thermostats was a new water pump, some sort of sensors, and oil filter (in the oil hopper).

You would think if this was a major problem it would ALWAYS sound and not be so intermittent.

My next thing is just buy a new ETEC ;)
 

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You could have a fuel restriction. Same alarm and slow as a overheat. Perhapes some trash on the fuel pickup screen or a clogged fuel filter. Could even be a bad vaccuum switch.
 

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Like Joe said, it could be a lean fuel alarm also. Pulling the connector off the vacuum switch will help determine which way to look.

The other thing is maybe you picked up some seaweed or plastic bag across the water inlets. The first thing to do is stop, put the motor in reverse to clear any debri, then reset and see if the alarm sounds again. Intemittant problems are the worst to figure out.
 

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How often should you change thermostats.I flush after every use.200 96 ocean runner.Thanks.
 

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Discussion Starter · #12 ·
Guys... could NOT priming the bulb cause the alarm to go off? (fuel restriction)

Come to think of it, I think I forgot to do it before starting the engine.

Thanks for all of your help.
 

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I'm surprised the motor started without pumping the primer bulb with the motor being tilted up for a month. There wouldn't be any gas in the carb bowls.

How old are your fuel lines and primer bulb? Any sharp bends or hardening of the fuel lines?
 
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