AQ125A over heating

[Joseph Graz]

I have a 1982 bayliner with the volvo penta aq125a and Im having a cooling problem with it. Im changing the thermostat today and I opened the water chock on the bottom of the exahust manifold and it had grit coming out is there a way I can flush the system to get it all out I think it might be cloged but I don't know if that's were it is or not

 

[bondo]

I have a 1982 bayliner with the volvo penta aq125a and Im having a cooling problem with it. Im changing the thermostat today and I opened the water chock on the bottom of the exahust manifold and it had grit coming out is there a way I can flush the system to get it all out I think it might be cloged but I don't know if that's were it is or not

Ayuh,.... The Impeller is Always the 1st place to look, in Any overheat situation,....

After ya rebuild the impeller pump,...
Just run yer motor, 'n pull the drain plugs outa the block/ manifold,...
That'll flush all the crud out,...

 

[pugetsounder]

Need way more information. Is it over heating on the hose in the driveway? is it over heating while on the water on plane? When was the last time you changed your exhaust manfolds? Are you getting water through to the seawater strainer?

All manifolds get a bit of rust and scale in them. Pull the drain plug and push a coat hanger or something up in there until water comes out. If they are original or old it might be time to replace before they fail and you get water in your cylinders which can cause major problems.

Are you on the hose in the driveway? Did you plug all holes on the drive? there is a drain hole at the bottom that needs to be plugged as well as the water pickups on the lower side of the drives with the rubber ears. If all holes are plugged and the hose is running then check the seawater strainer. If you're not getting water to the seawater strainer then yes check the impeller.

Does it get warm while on plane? There is a water gooseneck pickup on the upper part of the drive that gets corroded and will start sucking air instead of water but only on plane. While idling around the pickup is submerged and the problem won't show up until the boat is on plane.