I have a 98' Merc 175 and i'm new to big motors, last one was a 85' 90 hp Merc.

Well last trip out the alarm sounded while I was accelerating to put the boat on plane. It stopped before I could get it shut down. Then sounded again when coming off plane. It did this three times. It didn't do it when I headed in to the ramp.

Any and all help will be greatly appriciated.

Most outboard alarms sound because of oil issues.

This could be for over heat or oil alarms. I have a 04 Merc.150 and my motor did the same thing. But I just put my boat in the water and when I started to go on plane the alarm went off but it was the heat alarm ( the oil alarm and the over heat alarms are different sounds) .

So I took it to the dealer and he said it was a bad sensor and he put a new one in. It was good for about a month,I was fishing a tournament and it did it again! So now they told me that it was the water pump and they replaceed that and that must of been the problem. In the Merc. book it says to change the water pump every two years. The part was $28.00 and the labor was $ 150.00, hope this did some help!