Just quit running

[mattias]

The mercruier 350 mag in my 240sd just quit running and now won't keep running? HELP!

 

[mattias]

I let it cool down a minute and it fired right up and seemed to run great - then just died after about 10 minutes (water psi is only showing .1 on my smartcraft Guage? Any ideas why its doing this?

 

[Chip S]

What year is your engine. The Cool Fuel III modules were not very reliable. If your water pressure is down you may be getting vapor lock in your Cool Fuel III module. If it's not vapor lock the module may have failed. I'd start by looking at your Cool Fuel III module.

 

[mattias]

Its a 2005. Where is the "Cool Fuel 3" module located? I'm getting pretty low (hardly any) water (fresh water lake) coming in, so if i can figure that out - maybe that will get the vapor lock issue taken care of...

 

[Espos4]

The Cool fuel 3 module would be mounted low on the starboard side, below the alternator and slightly rearward.

If you are not getting any raw water in, you need to solve that first. Could be as simple as a plastic bag wrapped around the drive blocking the inlet holes.

 

[Chip S]

When was the last time you changed the water pump impeller. Mercury recommends changing the water pump impeller every 3 years. I change mine every 2 years.

 

[mattias]

We just bought the boat at the beginning of last season and the dealer we bought it from said that the impeller was changed the season before...

 

[Sea-Ya]

Possibly bad fuel. Check the fuel water separator and see if there is water in it

 

[kanddr]

Start with the simplest and most likely source of no water flow: the impeller. It is 2 years old at a minimum and is most likely the cause.