DMotorTrouble
New member
Hi everyone!
I could really use some help here, I've got a 2001 Mercury Bigfoot, 25hp 4 stroke that's overheating after 3ish minutes if I run above an idle.
It's running on a fairly shallow sandy river.
Removed and replaced thermostat, no change, still overheats.
Ran the motor with thermostat and thermostat cover removed, my question is, how much water should be coming out of this opening?
Here is a link showing the motor running without the thermostat cover on.
https://youtu.be/2dU_bg85oVM
Any ideas what my next step should be?
Thank you very much in advance for any help you can give me!
Other steps taken:
Removed lower unit and inspected, impeller, looked to be in good shape but one fin may have been installed backwards.
Reinstalled the impeller, no change, still overheats.
I've replaced the impeller and thermostat.
Installed it following instructions here
https://youtu.be/cKD26YcZPT0?t=400
Still overheats
I removed the exhaust cover per page 230 of the below service manual, there was a tiny dusting of sand in this, I then shot compressed air everywhere I could get to under this cover.
Found service manual here
http://forum.rentboat.dn.ua/manuals/merc/25.pdf
Still overheats....
I could really use some help here, I've got a 2001 Mercury Bigfoot, 25hp 4 stroke that's overheating after 3ish minutes if I run above an idle.
It's running on a fairly shallow sandy river.
Removed and replaced thermostat, no change, still overheats.
Ran the motor with thermostat and thermostat cover removed, my question is, how much water should be coming out of this opening?
Here is a link showing the motor running without the thermostat cover on.
https://youtu.be/2dU_bg85oVM
Any ideas what my next step should be?
Thank you very much in advance for any help you can give me!
Other steps taken:
Removed lower unit and inspected, impeller, looked to be in good shape but one fin may have been installed backwards.
Reinstalled the impeller, no change, still overheats.
I've replaced the impeller and thermostat.
Installed it following instructions here
https://youtu.be/cKD26YcZPT0?t=400
Still overheats
I removed the exhaust cover per page 230 of the below service manual, there was a tiny dusting of sand in this, I then shot compressed air everywhere I could get to under this cover.
Found service manual here
http://forum.rentboat.dn.ua/manuals/merc/25.pdf
Still overheats....