Continous horn alarm

[foreman33]

Well here is another problem that I ran into yesterday. I have a 1989 Johnson GT 150. Model # J150STLCEM. I was at the dam and was running along at about 5200 RPM when all of a sudden the horn started sounding continously. I immediately shut it down and tried to find the problem. I let it set for a half hour or so and tried to start it up again. All seem fine until I gave it full throttle and then the horn went on continously again. I shut it down again. Couldn't find anything wrong. I restarted again and all was fine until I go above 1500 RPM's and the horn sounds again. As long as I kept it around 1000 RPM's all was fine. No horn and I could run it back to the launch. What is it with this continous horn above 1500 RPM's??? What do I need to check out with this problem???

 

[Walker]

Re: Continous horn alarm

Continuous alarm is the overheat signal. When you run higher RPM's the motor needs more cooling water. Time to replace impellor most likely.

 

[Dhadley]

Re: Continous horn alarm

If the horn shuts off as soon as you pull back on the throttle, it could be the fuel restriction warning.<br /><br />If it is the water pump dont forget to replace the deflectors in the block too.

 

[foreman33]

Re: Continous horn alarm

Well if it is overheating was doesn't the horn sound when I drop it back down to 1000 RPM's? I was about 5 miles from where I launched so I kept the RPM's at 1000 and the horn never sounded and I was able to get back to the launch site. I turned the engine off a few time and restarted it again and every time I would go about 1500 RPM's and above the horn would sound. As long as I kept it lower it was okay, no horn. I did a compression check today and here are the results, 90,91,90,90,91,91. These results seemed pretty good to me since there was hardly any variation. I put a new water pump in it last year and I always make sure it is in the water or has the muffs on before I start it. With the muffs on today and running at 1000 RPM's the water pressure was 2 to 4 lbs. Closer to 4 though. I didn't rev the engine up any to see if it would go higher. Is this normal for the RPM's with muffs or should it be higher??

 

[Mark Noteware]

Re: Continous horn alarm

That engine has a low fuel pressure sensor. You have a restriction somewhere... tank clogged filter, or water separator.<br /><br />Mark

 

[foreman33]

Re: Continous horn alarm

Where is the low fuel pressure sensor located? I have 2 20 gallon tanks and I switched tanks to see if there was a problem with the one I was using but it didn't make any difference. Both tanks were almost full. I put a new inline fuel filter in last year and also replaced the bulb and hose to the motor. I assume that by water seperator you mean a filter of some sorts. The only filter that I see is the inline filter. Is there one that I'm missing somewhere?

 

[foreman33]

Re: Continous horn alarm

Well guys I found the problem with the continous horn above 1500 RPM's. The primer bulb is only a year old but it rattles severly when you shake it and it had several cracks in it. You could blow into it sometimes and the aid would come out but if you tilted the bulb downward and tried to blow in it now air would come out. This is what was restricting the gas flow to the motor above 1500 RPM's. I replaced the primer bulb and took the boat out today and it screamed. I had it cranking at 5600 RPM's and it never missed a beat. So it definitely was a fuel restriction that was causing the alarm to go off. For $5 it solved my problem thanks to all of you for the great input that you gave me. Keep up the good work guys. Much appreciated. I have an OMC service manual but I can't locate where it is right now. The Clymer manual that I have isn't very good at all. I couldn't find anything about the alarms at all in it. I hope I can soon find my OMC service manual soon. Again thank all of you for fine help. I hope someday I can help one of you with a problem. Don't make it too hard though. I'm learning from all of the great input that you give to other people. I hope you all catch a boatfull of fish and have a great day.<br /><br />Mike