Miked45281
New member
Hello - I have searched and searched; tried and tried; without success... My 1994 150HP Mariner outboard on my 1994 Ranger 482V bass boat continues to active the temp/overheat alarm. This occurs consistently after about 3-5 minutes of operating in excess of 3,000 RMP's. I have read many threads and tried many different suggestions. I have replaced the entire water pump assembly four times over the past 24 months, at about six month intervals, flushed the cooling system, replaced the thermostats twice. I took it to a local mechanic which did the entire water pump/impeller, thermostats (Mercury Parts/Products only) and flushed the entire system. It did seem better for about 30 days, but then back to the same old beeping alarm again! The water coming out the pee hole stream is pretty warm, and sometimes hot (with visible steam coming off of it in the winter months). I have tried removing the thermostats altogether to increase the water flow to the cylinders, with no luck. I can't really afford a new outboard so I am hoping that someone might have some institutional knowledge or experience of what might help remedy or improve this annoying issue. It puts a damper on fishing with my Grandson! =)