Guys,


I have a 1974 M440 inboard. The engine was sitting for the last 10 years and I have replaced all the hoses and cleaned the carb. It did run fine for a few seconds out of water. I tried to flush the engine with a garden hose by hooking a garden hose to the intake hose. I also removed the thermostat and rerouted the hose at the thermostat to outside the boat to prevent water from going to the exhaust. When I turned the water on, a little came out by the thermostat. After a while it looked like it was coming out at the head gasket. Should I have expected that and is there away to ensure the cooling system is not blocked. I did take the head off that had the leak but want to be sure there is something I need to do before reinstalling.


Thanks for any help.

 

If your lucky it is probbly leaking out a freeze plug they rust if the engine sits
has the boat been sitting out or in water and was the engine/boat coverd?
if its a head gasket that could be bad ...rebuild time

 

i have a big Q. did chrysler NOT use brass freeze plugs in a marine engine?

 

I do not have the engine out of the boat. The plugs on the head are rusted through. The plugs on the engine can't be seen easily. The passages do look very rusted. Is there a good way to clean it?

 

plugs rusted in the heads? time for some Marvel Mystery Oil. and some guys like other products and fine to. it just that iam prejudice for MMO.

 

If the heads are rusted I can almost guarantee the block freeze plugs are bad too. You can do it without removing the motor but it will make a mess. Easy way is to remove the plugs and use a long bottle brush and a hose and flush with water. May be easier to pull the motor There are plugs on the back side of the motor that may need to be changed also.