Have a 96 Mariner 30hp with oil injection. Were out last weekend when a sudden high pitched alarm went off. It was a continuous beep which after a while increased in pitch. Checked the oil injector reservoir and it was very lowtyhough the gauge showed 3/4 full. We cruised slowly back to the boat ramp which took about 10 minutes. The alarm started at high revs but continued even when idling out of gear. Water flow from the pump was good and the water was cool. We filled up the oil reservoir but the alarm is still sounding. Exhaust gases are blue and the performance of the motor does not appear to have changed. The alarm still goes off everytime I start the outboard. Any ideas on the the cause and what I might be able to do to fix it?
The alarms are there to tell you something is wrong. Continuing to run the motor in this situation is asking for trouble. What you are hearing is an overheat alarm, and if its valid, you run a good chance of seizing the motor. It may also be a short somewhere in the wiring that is causing the alarm but you need to find the true cause before running the motor anymore. The low oil alarm is an intermittant beep-beep-beep-beep. Doeas the alarm sound even if the motor is not running but the key is in the ON position?
The system is easy to check. Pull the tan (on my Merc)lead off the head temp sensor, or disconnect the tan lead from the wiring harness going to the lead coming out of the temp sensor (sensor is visable from the rear of the engine, coming out of the head's water jacket near the spark plugs) and see if the alarm stops (with with ignition key on).If it stays on you have wiring problems. If it goes off and the engine is cold it has internally shorted. Alarm position for this switch is a direct short to the engine's block.While you are in there you might check your thermostat or just replace it. Mine is stamped with 120 degrees on it and if you put it on a pot of water and heat to a boil, you will (should) see the end (oopposite the pellet) extend about 1/4 inch from the body when fully opened. It should come off it's seat at around 120 and be fully opened within 10 or so degrees.A candy or baking thermometer in the water helps to know the exact temp. Turn the fire down low so that the sensor in the thermostat has time to respond to the water temp. It is deliberately made large (the pellet) to measure average temperature.If the water boils and the end hasn't extended get a new one......iboats has the whole kit (gaskets included) for about $13 bucks. Just ordered one and works just fine. Checked it in a pot of water before installation.Mark
30hp Mariner warning alarm won't stop.
The low oil alarm is an intermittant beep-beep-beep-beep. Doeas the alarm sound even if the motor is not running but the key is in the ON position?
Linear Mode
