sounds like its getting hot. check the water flow tube make sure its peeing out water good.

| Search Fishin.com |
My alarm started going off on my Tracker Pro Crappie Mercury 50hp 2 stroke. Only at high throttle and would quit if I slowed down but would sound again if I full throttled. Never once did it at idle or medium speeds only when I opened it up. Any answers or similar problems. Seems like I seen another post with similar problems.
sounds like its getting hot. check the water flow tube make sure its peeing out water good.
I have a 1993 150 Evinrude that did the same thing, turned out to be the fuel pump, seems that the fuel and oil pump were the same unit. Hope this helps and good luck
Does it have oil injection? If so, have that checked. I had a merc that did the exact same thing, and it was the oil injection.
Guys it's a solid tone alarm....not a beep, beep, beep. I'll have to check further but from what I understand the constant alarm means overheating. It was peeing a stream but may not be getting enough water drawn in at higher RPM's
Wichita you are right about the solid tone alarm... I had the same problem
with a Mercury 150 like you said it was peeing a stream but would still get the alarm . I had to change the H20 pump to fix the problem.
Could be a faulty thermostat. I'd replace the water pump AND the thermostat if it's been more than two years since last done. A steady alarm is an indication of "overheating". If you continue to run the outboard, you'll pay dearly for it later!!! You might consider starting a thread at iboats.com. There's some very knowledgeable folk on that site who will steer you in the right direction........ ;-) ....... Good luck.
You need to replace you water pump impeller.You can get by with just the impeller if you haven't gotten it hot enough to warp the water pump housing. I hope you get it fixed... that isin't a bad job at all...
Had a friend with a 150 Merc with the same problem. Would do O.K. at low r.p.m but at higher speed the alarm would sound. Long story short, he had recently replaced the impeller but put it in backwards. He found the problem when he checked to see if the housing was bad and seen that the impeller was put in backwards. Turned the impeller the correct way and everything was fine.
