Cooling problem
 

HELP!

I fired up my boat on the hose for the first time of the season yesterday and the first thing that happened was the freeze plug blew out and dumped water into the bilge. I tapped the plug back into place and fired the engine up again. The plug stayed in, but not a drop of water came out of the exhaust pipes. I opened the manifolds and they were full of water and i jammed a coat-hangar down there to maybe clean out a blockage, but i still have no water pumping out the back of the boat.

I replaced the manifolds and riser elbows last July and I would think they are ok besides a little internal sluffing.

Can anyone tell me where I should start troubleshooting?

btw, the engine is an older 5.7L Merc 260 with an alpha drive.

Thanks!

Re: Cooling problem
 

If my memory serves correctly, on your thermostat housing there should be a couple of hoses. 1 small 1" hose goes to each riser. If you take the hose off of the thermostat housing, you will see a ball and spring ( check valve ) that regulates the water flow to the riser. It may be broken , rotted or just stuck. That may a good place to start to look. Have you checked or replaced the seawater pump?

Re: Cooling problem
 

Thanks. I haven't checked the seawater pump yet, but i will. The damn weather isn't cooperating.