VOLVO AQ125b Overheating at WOT/Muffs/Tank

[joemamma_222]

Hey all was out with a buddy last night trying to figure out his overheating prob. Last week he was on the lake and noticed an overheating problem so when he got it home we changed the thermostat and impeller. After changing we hooked up the Muffs and plugged the hole in the leg and noticed we werent getting any water into the system. I told him these 270 legs dont cool real well on muffs. So Figuring the Lines has no water in them and they needed "primed" with raw water we filled a barrel and lowered the leg into it started the motor and still the impeller was not Drawing the water in. We unhooked the raw water "IN" line from the Stainless tube and put a hose directly into it. Wala the motor was cooling. Then we took th hose and ran water down the stainless tube to the leg (thinking we mighta had a blockage) the water was flowing out the vents in the LU and all seemed fine untill I plugged the vents with my hand and I did notice water comming from the middle of the leg where the pickup tube runs up about midway where the LU swivels. Anyway we took it to the lake anyway and the motor cools great at Idle but when on plane it'll peg the Temp gauge real quick. Is that pickup tube supposed to be completely Air/water tight ? Or do we have a water pump issue ? I was thinking it might be sucking air when we are on plane and the pivot point is up outta the water. Anyone had this issue before ?
Sorry for the long winded But I wanted to let yall know what we've done so far...
Thanks !
Joe in Ohio

 

[schnorrd]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

If its what I think you are not going to like it.I am not a mechanic but had the same problem so I won't talk in technical terms.
There is about a one dollar plastic fitting that connects the pick up water outside to the hoses inside. if it cracks and mine did at low idle it is still under water and no overheat, but on a plane it is out of water and sucks air.
The bummer is you have to pull the outdrive off to get to this $1.00 part
Good luck Doug

 

[Don S]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Any air leaks between the water pickups and the raw water pump will cause the pump to suck air and not water. The most common place is the hose connecton on the outdrive where the hose attaches. The connecter usually corrodes Under the hose. Remove the hose and check it.

 

[Don S]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

There is about a one dollar plastic fitting that connects the pick up water outside to the hoses inside.

270's don't have that part.

 

[joemamma_222]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Thanks Don appreciate the help....
Are you talking about part #28 on this diagram ?
http://www.dougrussell.com/partscat...,1880,1881,1882,1866,1887,1870,1886,1875,1877

The leak I saw looks if I remember right that it's directly to the right of part 14. When I get off work I can dertermine exactly. But It's leaking below part 28 within the next 6 inches. Will we have to pull the whole leg ?

 

[Don S]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Yes, part 28

 

[joemamma_222]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Lastly Will I have to pull the Whole leg ? Or can the pickup tubes be pulled and repaired with just pulling the top housing (upper housing and bellows off ) Just wondering if the tube can be removed outta the top ? and resealed or inspected or new orings put in from the top

 

[Don S]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

I doubt it's the tube, it's a heavy walled SS tube. Determine exactly where the leak is from there is a gasket at the top of the tube for the hose connection, and a big oring between the lower unit and the intermediate housing is.

 

[Maclin]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

No intention to dilute the thread, just adding my experience with this part.

I also had trouble getting mine to run a good flow of water on muffs. It always kept things cool in the lake but at longer cruises the exhaust risers would get warm, then they cooled down at idle. It (part#28) is underwater at idle so it runs ok then. As you come up on plane it can start letting air in. Mine was corroded, but could not see any evidence of it from the outside. I was replacing bellows and u-joints anyway and bought that part new as well on advice from another source. When I took it off I was enlightened quickly. The neck was corroded in a V shape with the point starting exactly where the hose ended and then widening out to the end of the neck, very sneaky. I replaced the hose as well, although it was probably ok.

I am not sure what is going on chemically with that paricular junction but it definitely has a reputation going.

 

[joemamma_222]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Thanks Maclin ! The leak itself looks to be under that part though which is a little confusing. Like almost like it;s below the exhaust below. I'll get a better eye on it tonight. but when Hose pressure is applied from the inside rigid pipe to the outside les and the vents are blocked off it's definately not water tight.
Thanks for the advise !

 

[JAL51974]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

I had a similar problem the summer before last with that part on the 270.
Here is what I did:
had a similar problem part #11 in the diagram and/or the gasket #29 or the #28 was the problem. Only way to diagnose it I found was to run suction from the H/E -that is the connector leading to the H/E -and put something like shaving cream at all the joints between there and the outdrive as well as on the outdrive itself wherever you see a pivot point (and there are several). The suction used was a shop vac but you could use anything like that. My idea was to see and hear where the air was being sucked into the system where it should not be! Worked great and I could then replace the washer or bushing that was the culprit. Those bushings 11 and 29 between the different parts of the outdrive are a real pain to get to without taking the entire thing apart but it can be done.


Takes patience but you can get it.

Joe

 

[joemamma_222]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Joe did you just take off the upper housing ? I was wondering if the Tube could be pulled out from the top or serviced from the top without taking off the lower or intermediate housing...? Thanks for the info !

 

[joemamma_222]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

Ok stopped at my buddies house and Looks like part no# 11 is cracked and in pieces ;
http://www.dougrussell.com/partscat...,1880,1881,1882,1866,1887,1870,1886,1875,1877

anyone have any suggestions on what other parts I should order while ordering that part ?
Also anyone have any ideas on how to get at it easily ?
I think we'll replace the bellows while we are at it also. Does the outdrive actually pivot on the Stainless steel Pickup tube ?
Thanks for all and any advice !
Joe

 

[Maclin]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

The #28 water neck hose connection for sure, and maybe the hose that comes thru the transom and hooks to it. You will also be able to check the u-joints once you have the upper unit off, and r&r them if necessary.

 

[Maclin]

Re: VOLVO AQ125b Overheating at WOT/Muffs/Tank

As you said, might as well do the drive bellows at this time, hardly any more work involved.