Outboard Alarm

[stein86744]

I have a 1987 70hp Johnson. Recently an alarm has been going off sporadically i.e occasionally when I start the boat and also when running the engine for awhile. The alarm sometimes stays on indefinitely, and sometimes shuts off after a minute or so. Also, if I shut the boat off and start it up again the alarm often does not come back on for a bit?? Is this a known issue? Do I check the sending unit? Wiring of the alarm? Oil pressure? Cooling system? Thanks!!

 

[Dhadley]

Re: Outboard Alarm

Sounds like a fuel restriction warming. Look at the whole fuel delivery system including the anti-siphon valve if you have a built in tank.

 

[willie]

Re: Outboard Alarm

I had a similar problem with my johnson motor. I replaced the VRO oil pump on the motor and it took care of the problem. What I was told was it was getting weak and would more than likely stop working soon. It is an easy fix. Hope it works.

 

[stein86744]

Re: Outboard Alarm

Willie and DHadley,<br /><br />Thanks for the replies. I will check the gas system and the oil pump. The strange thing is that the engine runs fine and that the alarm sometimes goes off immediately upon starting the engine - so it seems strange that the gas flow is being constricted or otherwise. However, I have had a strange gas smell that makes me wonder if there is a fuel system problem. As for the oil pump - where is the best place to get advice on the repair/install? Thanks Again!

 

[willie]

Re: Outboard Alarm

You can get a VRO pump from any OMC dealer, it should be a standard item, if they have any left due to the fact they filed Chapter 11. Clymer's shop manual can be purchased at just about any boat supply store or even some book stores will order it. Very easy to install. As another test, When the alarm goes off, try putting the motor in neutral and throttle up while in neutral to see if this stops the alarm.

 

[dougb]

Re: Outboard Alarm

A few years back I also had an intermittent problem with the warning horn going off on one of my Johnson 235hp outboards. It drove me nuts, I was not over heating, had plenty of oil and fuel being supplied, but it would still go off, sometimes steady and sometimes pulsing. I finally discovered that condensation had developped under the the small plastic cover on the side of the VRO unit where the wires enter and the small electrical contacts are. I cleaned them up and tested all systems, and everything worked ok. Try this before you replace the unit.

 

[Dunk]

Re: Outboard Alarm

I don't think OMC started with fuel restriction sensors till about 88-89 and that was on the V6's.<br /><br /> My guess is a bad heat sensor. On the top of the cylinder head you'll see a tan wire coming out of the the temp sensor. On that wire you'll see a rubber sleave with a tab on it. Grab the tab and pull it back exposing the connector, disconnect it, then start the engine. If the alarm doesn't come on you either have a hot engine or the sensor is bad. The sensor will trip the alarm at 205 degrees. If the engine is that hot you won't be able to touch it for even a second. If the engine is at it's right temp(145-165) at idle you should be able to hold yor hand on the cylinder head for a few seconds. <br /><br /> If you don't have a temp gauge you can buy heat sticks from any auto parts store. Buy a stick that will melt at 180 and above. Their like crayons, you smear some of the material on the head, if it melts and puddles up she too hot. If the engine is cool the temp sensor is shot and grounding out before it should. Replace it.<br /><br /> You can buy rebuild kits for the VRO pumps for either the front end(fuel) or the rear end(oil) for about 15 bucks each, complete with instructions in 5 different lang. Personally I dump the VRO and just go with a standard fuel pump that will bolt right to the intake manifold where the pulse limiter is now for driving the VRO.<br /><br /> If this was a fuel restiction problem then priming the ball while the alarm is going off should shut the alarm off.