Back flush?

[mestrezat]

I've got a Ford Lehman 80hp engine on my sailboat that love over heating. I've already posted about it but now another suggestion has come up from another cruiser. They suggest "back flushing" the engine. I know how to flush(just pour in a bottle of flush stuff and water, start the engine and run it for a while and drain and refill with coolant) but how do you "back flush" a marine engine?

I've replaced and checked all the water hoses, the injector has been replaced. The heat exchanger has had both end caps taken off and I can see through the small tubes in it. I pulled off the mixing elbow in the exhaust and found it about 20% blocked. Got it all chiseled out and cleaned and reinstalled.

When the engine is running, there is a lot of water coming out the exhaust so I'm figuring there is a problem in the "fresh water" system. With the engine just started, I pulled off the cap on the water tank and I could see water flowing through the tank. I thought the thermostat wouldn't open and let the water flow till it hits about 180 but mine seems to flow all the time. I've got a new thermostat and fresh water pump coming in a few days but I've been told I should really do a black flush.
Any suggestions how or thoughts of what else I can look at to stop the overheating?

[Jsta_Rebel]

Originally Posted by mestrezat

I've got a Ford Lehman 80hp engine on my sailboat that love over heating. I've already posted about it but now another suggestion has come up from another cruiser. They suggest "back flushing" the engine. I know how to flush(just pour in a bottle of flush stuff and water, start the engine and run it for a while and drain and refill with coolant) but how do you "back flush" a marine engine?

I've replaced and checked all the water hoses, the injector has been replaced. The heat exchanger has had both end caps taken off and I can see through the small tubes in it. I pulled off the mixing elbow in the exhaust and found it about 20% blocked. Got it all chiseled out and cleaned and reinstalled.

When the engine is running, there is a lot of water coming out the exhaust so I'm figuring there is a problem in the "fresh water" system. With the engine just started, I pulled off the cap on the water tank and I could see water flowing through the tank. I thought the thermostat wouldn't open and let the water flow till it hits about 180 but mine seems to flow all the time. I've got a new thermostat and fresh water pump coming in a few days but I've been told I should really do a black flush.
Any suggestions how or thoughts of what else I can look at to stop the overheating?

If I were you, I'd call the guys at American Diesel and talk with them. They are the Lehman pros and always willing to help.
American Diesel Corp

[mestrezat]

That's where I bought the new fresh water pump as well as the thermostat. They are the ones that suggested the "back flush" but didn't tell me how to do it after I asked. new stuff should be here Monday hopefully

[mestrezat]

I've dealt with Brian and John for a long time and I agree, they are the people to go to for help. Blew the engine in Micronesia a few years ago and they got us all taken care of.