Lower Unit

Status
Not open for further replies.
O

Old sarge

Recruit
Joined
Apr 30, 2012
Messages
2
My 50 HP 4 stroke (2001) outboard motor overheat alarm sounds (steady alarm) only when at full throttle. It runs fine at lower speeds. I have replaced the water pump, pump housing and the thermostat. The tell tale water stream is strong and warm. When the alarm sounds the engine loses power. anThe alarm is silenced by shutting off the key. I can restart it immediatly and the alarm goes off and motor runs fine as long as I go 1/2-3/4 throttle.
Any suggestions? Could it possibly be the oil pressure alarm?
Thanks!
 
F

FlipFlops365

Cadet
Joined
Jun 12, 2012
Messages
15
Re: Mercury 50 HP 4 Stroke (2001) Outboard OVERHEATING alarm

Re: Mercury 50 HP 4 Stroke (2001) Outboard OVERHEATING alarm

I am having the EXACT same problem on my 2002 Mercury 50HP fourstroke Bigfoot. I haven't started replacing parts yet as it only happens WOT which I rarely use.

According to the manual I think it lists 5 things that a continuous alarm could be: overspeed, oil pressure, high voltage, coolant sensor and overheat. Correct me if I'm wrong.

I initially thought mine was overspeed because my tach jumps around a bit but I recently installed a Blue Sea Add-a-Battery with dual circuit and I think I may have wired something improperly causing high voltage.

Let me know if you figure out your issue and best of luck.

Thomas
 
7

72 Fury

Cadet
Joined
Aug 6, 2011
Messages
28
A friend of mine has a 2001 50hp Bigfoot mercury and it would sound the alarm after a couple of minutes at WOT, or sometimes if your reversed and then went forward again. If you turned motor off and back on sometimes it would go away right away or we'd have to wait a few minutes. Anyway, we went to replace the impeller and found that the blades were out of whack and the one gasket was partially missing. After replacing the impeller and 3 gaskets the water stream was instantly better and the problem has gone away. I think he got the kit from Marine West and it was like $33 for impeller, gaskets, and plate.
hK7Unj4.jpg
 
GA_Boater

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
72 Fury said:
A friend of mine has a 2001 50hp Bigfoot mercury and it would sound the alarm after a couple of minutes at WOT, or sometimes if your reversed and then went forward again. If you turned motor off and back on sometimes it would go away right away or we'd have to wait a few minutes. Anyway, we went to replace the impeller and found that the blades were out of whack and the one gasket was partially missing. After replacing the impeller and 3 gaskets the water stream was instantly better and the problem has gone away. I think he got the kit from Marine West and it was like $33 for impeller, gaskets, and plate.
Click to expand...


Stop posting in old threads.

Closed
 
Status
Not open for further replies.
Top