Merc 225HP overheating

[SkipperG]

Hello

I have 2x 225HP EFI Merc's on my boat with about 230hrs on them. I recently had my engines serviced and both water pumps were changed.
The one engine is still running hot though and while running at about 3500rpm I have to switch it off after about 10mins of riding as it's getting very hot! I haven't seen if it will actually sound the overheating alarm if I don't switch off but I'm pretty sure it will.
If I leave it off for 30 sec's on then restart it it's fine and then I'm good for another 5-10mins before I have to repeat the process. I have spoken to 2 service centres and the one says it's the thermostat and the other says it's the poppet valve.
Any help would be greatly appreciated!

 

[1nebel0]

Re: Merc 225HP overheating

Pull out the thermostats because salt water will kill them...next would be the poppet valve...it is designed to open up around 2500rpm to dump the hot water..if it is not working you will over heat as the water isn't be dumped quick enough...great advice from the shops...let me know if that does the trick...Steve

 

[SkipperG]

Re: Merc 225HP overheating

Thanks!!

I replaced the poppet valve and it's much better. I'm just waiting for the thermostats to arrive and then they'll be changed as well!

Another problem has cropped up though!!! I'm getting 4 beeps every few minutes. I checked the oil well on the motor and it is not filling. If I top it up the alarm is gone and when it's drops by about a ? it starts again.
I have opened the bottle while the engine is on and it's not filling. Some help please?

 

[1nebel0]

Re: Merc 225HP overheating

There is a port on the starboard side of the motor(right side when standing in back of motor) that has a hose that will go to your on board oil tank...It is supposed to pressurize the tank and force oil into your outboard tank. Get the maual on how to bleed the system and get the air out.. I can't remember as all of my friends and myself don't use oil injection and premix to insure never an engine failure.......