volvo aq120b overheating please help

[farmboy4life]

hi i have a 1980 bayliner bow rider with a aq120b volvo motor with a closed cooling system and a 270 drive now my problem is it will overheat at 1/2 to full throttle i have checked all the water lines and sea water pump has been replaced , the heat exchanger is clean the thermastat is working i tested it and the timing is on just checked it i am lost can it be the coolant pump or the pick up lines sucking air please help

 

[captmello]

Re: volvo aq120b overheating please help

Yes, they suck air at the fitting right below the ujoint bellows. Pull the hose off the fitting and have a look at it.

 

[farmboy4life]

Re: volvo aq120b overheating please help

Yes, they suck air at the fitting right below the ujoint bellows. Pull the hose off the fitting and have a look at it.

ok will go look ty for the reply

 

[farmboy4life]

Re: volvo aq120b overheating please help

well pulled thim of and the 1 on the hull is good but the one on the lower end is like the 1 you have and i found a o ring stuck in the lower 1

 

[captmello]

Re: volvo aq120b overheating please help

If it was mine, I'd pull the upper gear box off in order to properly replace the intake fitting and gasket that goes under it. The seal under the fitting has a built in oring that faces down when installed.

Here's what you need, comes with the gasket.
http://www.iboats.com/Thermostat-Housing-Sierra/dm/*******.911528279--**********.814468564--view_id.173338

Depending on past maintenance, you may want to change the bellows as well. You'll need the two orings to reinstall the upper gear box.

I'm curious where the oring you found in the hose came from. Perhaps it broke away from the seal under the intake fitting.

Let us know what happens.

Good luck!

 

[farmboy4life]

Re: volvo aq120b overheating please help

ok will do and i hope this will fix the overheating and i say 1 more thing i checked the water pump and it has alot of play in the shaft

 

[captmello]

Re: volvo aq120b overheating please help

I'm not that familiar with that type of pump. I believe there is a rubber coupler on the backside of the shaft. that may be were the play comes from.

I believe #34 on this link is the rubber coupler.

http://www.volvopentastore.com/Cylinder-Block-Aq120b/dm/*******.911528279--**********.814468564--store_id.366--view_id.325957