Alright, about month ago, the alarm went off (a steady buzz) on my outboard. I figured a piece of grass, wood, or whatever got in the water pump/impeller even though its still spittin water and has 5psi of pressrue. i idled it back to the ramp, not thinking much of it, because it was due for annual tune-up anyhow.

The discovered at the shop that in fact, it wasn't overheating, the motor had plenty of water pressure, BUT, the low oil sensor went out. They did my annual maintenance, replaced the oil reservoir/sensor under the cowling and I took it home.

I take it out to the lake, I get it up on plane and BEEP, BEEP, BEEP, BEEP every 2 minutes. it goes into RPM reduction mode, and I limp in back to the ramp. I take it back to the shop, they tell me that the oil sensor was not installed properly and they fix it, they take it to the lake, and discover that the motor is running rough. They put a new fuel line and water seperator, and it running running great no problems.

I take it back out to the lake to make sure, before I get ready to go on a trip and right away a steady buzz and the motor goes into RPM reduction mode. I limp it back to the trailer.

I've spent 575 dollars plus time and fuel getting to this point.

What would you do next? I'm not sure how to handle a mechanic that can't get it right. What should I expect.

I'd find a new mechanic for sure.

Take it to Tommy at Rockwall Marine .

Find a new shop and let them diag and fix it.

What motor do you have ?

Man have i been there. My first choice would be a new mechanic, prefferably one with a known good rep. The first thing they should have done is put the computer on it and it would tell them what code or problem caused the alarm. There are 3 main things to check first. Computer, compression and leakdown, and air/fuel pressures. That is if its a merc. Im lost on a yami

I had the same problem......frustrating

its a 2007 150 optimax

Try here, my uncle has been going here for years. Click

Same thing happened to me earlier this year. Was getting the beep beep beep then a constant BEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEP. Then it went into guardian mode. Oil tank in the boat had plenty of oil. I replaced the small oil tank under the cowling. I filled it went to the lake and backed the boat in and let it idle for a good while. No alarm, then I went and ran it. The alarm came on again. I went back to the ramp and called Rockwall marine and they told me to check the cap on the tank in the boat and make sure it was tight. Well it was tight but apparently not tight enough. I got almost a full turn on it. It was loosing prime and no pulling a vacuum apparently. Rockwall marine is the best. Thank goodness for guardian mode. Hope this helps.

Rockwall marine will take care of you.
What lights are coming on is important as well. Is it the oil or fuel or motor light?
Anytime you talk about oil starvation a compression check is in order. If you get by that the leak down is the way to go.
Sorry to hear this!!

Call 903 668 2022 we specialize im mercury outboards we don't work on any other motors but we don't open back until Jan 1St

If it's an older Merc first make sure the under-cowl oil reservoir is full to the very top so the float switch will actuate.

Next, if your alarm is still sounding AND the engine idles unreliably and seems weak it might have a partial failure of one of the two CD ignition modules. Use a $3 spark tester to check to make sure you have spark to the #2 cylinder. If you can't detect a spark then the associated CD module is bad.

Here's why failure of the ignition module would cause the oil injection alarm to sound: The primary pulse for #2 cylinder is used as a reference signal against which the alarm module compares the oil pump rotation sensor. If EITHER pulse is lost the alarm module signals that there is a problem with the oil injection system. And you won't find this in the repair manuals!

Most mechanics won't diagnose this problem correctly. They will insist that the nylon gear on the crank that drives the oil pump shaft is bad and advise you to remove the oil injection system and disconnect the alarm module. Their recommendation would just mask the real problem with the ignition module that would still exist.

All that being said, if you don't have a Merc, then as Rosanne Rosanadana would say, "Never mind!"

Good luck!

Good info

Count your losses and DONT go back.