Warning horn at low idle speed?

[7lazy77]

I recently got a pontoon that has a 1994 115hp Johnson motor on it. At continous lower speeds (trolling or leaving a no-wake area on the lake) after about 1-2 minutes, the warning horn goes off in short continuous increaments. The horn immediately goes off when I throttle up faster. According to the book, this signals little or no oil flow. Any other speed (other than the low idle), the motor runs great. What could be causing this???

 

[7lazy77]

Re: Warning horn at low idle speed?

Any ideas???

 

[7lazy77]

Re: Warning horn at low idle speed?

I guess this this question has everybody stumped??

 

[daselbee]

Re: Warning horn at low idle speed?

Not sure you have diagnosed it thoroughly and completely. It SOUNDS more like it is overheating at idle and sounding the horn, and as you pick up speed...(increased water flow) the horn stops.
I would put a IR temp gun on the heads to see what the actual temps are, BOTH SIDES, and then try to diagnose which sensor is triggering the alarm.
This is done by disconnecting the tan sensor wires at the various locations on the motor until the alarm fails to sound,while re-creating the conditions that caused the alarm in the first place.

Sensor wires are two in the heads for temp, one in the oil tank for low oil, and one on the VRO (OMS) pump for no oil.

If it truly is NO OIL, then I would immediately start using 50:1 pre-mix fuel in the tank until you resolve the problem.

 

[lexer440]

Re: Warning horn at low idle speed?

Well, the obvious one would be little or no oil. or Stuck float, bad pump, air leak, bad wiring, or a faulty warning horn. I would suggest running premix until you get it sorted because no oil is really not a good thing.

 

[7lazy77]

Re: Warning horn at low idle speed?

Thanks for the information on where to start! The motor is definately using oil, because the level is dropping over the past two trips. I will look into the other "possible" problems. Thanks again for you help.

 

[7lazy77]

Re: Warning horn at low idle speed?

UPDATE:.......
Took boat out today & experienced some more motor glitches. As I was pulling the kids around in the tube, I had a loss of power at wot. Throttled up several times & it would reach around 5000 rpm's then I would feel a jar & the loss of power. So I decided to shut the motor down. When I went to restart it, the motor was flooded, so I had to disconnect the fuel line & bleed the excess fuel out of the motor (this happened twice). I didn't want to do any harm to the motor, so I decided to call it a day.

Given the above info coupled with the warning horn going off at slow trolling speeds, what should I look at now as possible problems causing the motor issues????

 

[emdsapmgr]

Re: Warning horn at low idle speed?

A constant horn is an overheat. You are not experiencing this. Intermittent horns are an oil warning. The VRO system has two horns. A horn every 15-20 seconds indicates the oil tank is low on oil. Not a major fault-just fill the tank. A warning horn beep every second indicates a problem with the VRO pump itself. This is more serious, requiring professional help. I wouldn't run the engine till you resolve this horn issue.

 

[daselbee]

Re: Warning horn at low idle speed?

I don't think you have heeded our warning to go to pre-mix now. Engine loss of power at WOT can be caused by no oil in the fuel. Pistons will heat up, typically one, and then cascade into a swelling situation. The piston siezes in the cylinder, and shuts the motor down. A few mins later, after cooling for just a bit, it will re-start.

Go to pre-mix NOW. I hope the damage has not been done.

 

[locksmart]

Re: Warning horn at low idle speed?

Has this been solved?
I have had the same problems with a 1994 Johnson 70. Except I also have no water coming out from the tell tail.
But I do have tell tail if I put the ear muffs on with the garden hose.
Any thoughts?

 

[Sixmark]

Re: Warning horn at low idle speed?

Has this been solved?
I have had the same problems with a 1994 Johnson 70. Except I also have no water coming out from the tell tail.
But I do have tell tail if I put the ear muffs on with the garden hose.
Any thoughts?

Yeah you have a water flow problem, please post a new thread regarding your own problem and engine info, etc. This greatly helps in keeping things straight on the forum.