Alarm on Johnson outboard motor

[Ashland]

Just bought this used boat, 1980 Johnson 115 hp. The alarm goes off and don't know what to check, so I stopped the engine, it wouldn't start for about 20 minutes, let it set, then it started up again. When alarm goes off what should I be looking for?

 

[matt126]

Re: Alarm on Johnson outboard motor

I have a 89 j200 with alarm issues to first is it a steady beeb or an intermitt' beep if it is a solid beep you may have temp problems there are two temp. sensors on the top rear of the heads port side should have two wires starboard has one if it is like mine the tan wire is for the alarm you can disconnect it to see if the alarm stops This may help find your problem

 

[Ashland]

Re: Alarm on Johnson outboard motor

It is a steady beep, we shut down the motor for about 20 minutes, then it would not start, acted like a fuel problem, waitied another 10 minutes, and it started right up. The Alarm would not go off, so we had to disconnect it, don't know if it was over heating, it did not seem like it was. What would you check, once you shut off the alarm?

 

[Ashland]

Re: Alarm on Johnson outboard motor

We do have a Brown wire, that is the alarm, the other wire is a purple/brown wire, that is not connected to anything.
On the panel it reads: White/Black Sensor 1, Black/White Sensor 2, White/Black Sensor 3, Black/White Sensor 4.
My Manual I have is not helping, does not show the sensor's in the book?
Alarm Goes OFF, I disconnect alarm, water is flowing, what do you suggest I check next?
Your help is very much appreciated. I did change the oil/fuel to make sure it is a 50/1 ratio, since I bought it used.

Thanks'
Ashland

 

[matt126]

Re: Alarm on Johnson outboard motor

the steady alarm should be for temp problem or a fuel restriction you do not want to run it without the alarm you said you shut of the alarm how did you do this

 

[Ashland]

Re: Alarm on Johnson outboard motor

We disconnected at the control panel, we did not continue to run the engine, took it out of the water and came home.
We hooked it back up and now we want to go out and trouble shoot in the water to see if it is getting hot, just now sure how to go about this.
Manual we have does not say much.

 

[matt126]

Re: Alarm on Johnson outboard motor

I am not an expert but I sugest hooking your alarm back up & by process of elimination un hook your sensors one by one & see if the alarm stop you said you were mixin the gas an oil dose this boat have an oil tank was it ever oil injected if it has a vro pump & your mixing the gas you need to disconnect the wires on the oil side of the pump

 

[Ashland]

Re: Alarm on Johnson outboard motor

We also want to check the thermostat, do you have the best way to check that, this motor is one I have never worked with, Where is the thermostat located the book says two different places, not sure. I have worked on a lot of motors, mostly cars but this one has got me confused.

Any guidance you can give is much appreciated.

Thanks

 

[d.boat]

Re: Alarm on Johnson outboard motor

the steady alarm should be for temp problem or a fuel restriction you do not want to run it without the alarm you said you shut of the alarm how did you do this

My understanding is that only the V6's have a fuel restriction alarm. That engine only has a steady alarm for overheat.

 

[ezeke]

Re: Alarm on Johnson outboard motor

The alarm system on your motor is only for overheat. Service your cooling system: water pump, thermostats and water passage deflectors, in that order.

You should not run the engine until you find the cause and repair it.

Repeated running after overheat will usually blow the head gaskets at a minimum, so you should replace them.