Mercury engine warning signal

[billbraswell]

approx 1990 90hp mercury sat up for 6 weeks and now everytime i get over 4000 rpm for 60 seconds or so i get a steady warning signal. i'm not sure if this is an overheat warning or an oil injection warning. i can sit in marina with the engine running wide open and will never get warning, it only occurs while underway. the low oil warning is an alternating beep signal. it seems to me if it was overheating i would get same results while sitting in marina so i'm leaning toward oil injection tube gummed up. anyone else had this problem?

 

[hondon]

Re: Mercury engine warning signal

First of all ,why are you revving the heck out of this thing either in neutral or tied to the dock?This cant do your motor any good in either situation.

 

[Trent]

Re: Mercury engine warning signal

Disconnect the sensor wires one at a time and go see which one is causing the problem. The float in the oil tanks like to stick and cause this problem also.

 

[tradmker]

Re: Mercury engine warning signal

IT MIGHT BE THE OVERHEATING WARNING. I'M HAVING THE SAME PROBLEM NOW. MINE HAS PROGRESSED TO THE POINT IT WILL SHUT ALL BUT ONE PLUG. HAVE THE TIMING CHECKED AND THE IMPELLER. MINE GOT BACK TO ME ALMOST TOO LATE. THANK GOD FOR KIDS HUH LOTS OF LUCK

 

[JohnnyS]

Re: Mercury engine warning signal

I had a similar sounding problem on my older Merc. The steady alarm (screaming!) as I understand it is an overheat condition.<br /><br />In my case, when I got the alarm I was still getting a steady stream of water from the 'pisser'. So I thought it had to be something else. Well it turned out that there was a water flow blockage somewhere in the block. I happen to run my boat in salt water and flush after every use. But still got this problem (must not have been flushing enough).<br /><br />Well I wound up taking it to a mechanic who after trying his usual tricks, flushed the motor with some type of 'acid' which resulted in a bunch of gunk coming out. Immediately after, the alarm was gone and the motor runs better than ever. <br /><br />Get it checked before you fry it and wind up having to buy another.<br /><br />Good luck <br />John

 

[Mark.24]

Re: Mercury engine warning signal

Morning everyone!<br />On a similar note, I have a '83, 3 cyl with Thunderbolt ign. When I look at the cylinder head half way between the top and middle cyls theres a small bolt, with a approx 12mm head, sorry 1/2inch and maybe made of brass. Is there where I can place a temp gauge??? <br /><br />Mark