Hi,

I have a question. During running my motor would gives off long warning beep and lose power. I have to put the throttle in neutral for it to reset and the alarm stops. I did a research and it said it could be the cooling system or lubrication issue with the oil pump. The cooling system showed the water is shooting out pretty strong. I need an opinions or suggestions before I take it apart to fix it. The alarm doesn't come on often. Just every now and then. Sometime none at all on one trip and sometime a few times on a trip. Any recommendations appreciated. Thanks

Just an FYI on "water shooting out pretty strong": That alone does not tell you there is no cooling system issue. It confirms that cooling water is being delivered, so the water pump is operational. That's about it. Depending on water flow in the water cavities, you could have clogs or restrictions that prevent proper cooling, yet don't inhibit that tell-tale streamer from looking healthy. For instance, malfunctioning thermostat assemblies can be a culprit as they can restrict water, but not so much as to stop the water streamer. Crud/gunk build-up in a water jacket can also become an issue.

Sounds like oil reservoir is at low. I hayve Yamaha 150. Had warning n rpm limited to protect motor. Trouble shoot n see if your oil system is providing My is vmax so good luck

My 2016 150 opti was doing the same thing. I have a water pressure gauge and I felt the pressure was a bit low but was still cooling the motor and water was definitely coming out of the spout on the back of the motor. This weekend I cracked it open and replaced the water pump. The old impeller looked perfectly fine but when I replaced it the pressure on my gauge dramatically increased and the engine is running 9 degrees cooler at idle when hooked up to the hose (150 degrees vs 159 degrees). I have not had it on the lake yet but I suspect I may have found the culprit. Good luck and it’s never a bad idea to replace the water pump. If it doesn’t fix your problem just chalk it up to preventative maintence.

If it does it when slow running and the nose is high it could a be not enough oil in the reservoir. Keep the oil level over 1/3 full.

check the water strainer on the port side at the bottom of the block

Not sure if this will help, but I wanted to let you know about the issue I found on my 2013 Mercury 150 Optimax last year. My engine warning horn would beep constant for 6 seconds and then go quiet for a short while. It would repeat every few seconds. The engine went into the Guardian mode (reduced rpms). After researching online, I bypassed my small oil tank under the engine cowling on port side. That solved it. No problems since. Level stays full always, I plan to replace the oil tank one day.

The oil tank level float is bad and it indicates low oil level to computer. The computer reduces rpm's and gives warning beeps. By cutting wires and connecting together, it takes the bad float out of the loop.

Several things can set off the alarm, do you have a smartcraft gauge? It can give you some insight, there might be a blinking temperature or engine icon. It might help if you could describe what you are doing when it goes off, whether you're just getting on plane, or idling, or cruising down the lake. The reason you lose power is it goes into safety mode.