NO water circulation in AQ231B

So I finally got the opportunity to take the boat out for a bit on the lake. I recently have drained all of the old nasty fuel out of my boat, cleaned the carb, fresh good gas in and now it will run like a champ. Boat starts right away, idles real nice and revs great. Now I am tryin to figure out why it is tryin to over heat. I ran the motor in the lake, and it heated all the way up to 180, I shut it off and checked out the raw water pump, the impeller is fine, flexible and no broken vanes. I put the cover back on, primed with dish soap and ran again, same thing. My question is, since I know the raw water pump impeller is good, does the pump body need to be replaced or should I just replace the circulation pump on the engine first? I am not sure which is causing my issue and I hope with the help of the people here I can get a good run on the boat before I have to put it up next weekend. I am prepared to replace both pumps, just seems excessively expensive, and not really troubleshooting at that point. Would rather just replace the part that is broken, just don't know what part that is. I suspect that the Raw Water Pump body is damaged and not functioning properly, want a second opinion. I have checked all the supply system for obstruction, and have had no problems, I back flushed the drive from the hose into the raw water pump and back. No leaks, I even hooked up my shop vacuum and used soapy water at each junction looking for bubbles. Only thing left is a bad pump, one or the other.

Re: NO water circulation in AQ231B

check the hose fitting on top of the intermediate, just under the ujoint (upper) bellows on the outdrive. Pull the hose off and inspect the fitting. They commonly corrode and should be one of the first things to check after the impeller.

Re: NO water circulation in AQ231B

yep checked that. had another question. I saw online 2 different pumps. One by johnson and one by sherwood. They both have the same hose sizes, just different manufactures. Are they the interchangeable? I hope they are considering buying the Sherwood, it is cheaper. They appear to be made the same, so a few extra bucks savings is always nice.

Re: NO water circulation in AQ231B

I would just replace the impeller to begin with. May as well do the thermostat as well. The circulation pumps don't typically go bad. Careful when your throwing parts at it, they add up fast.

Re: NO water circulation in AQ231B

There are many troubleshooting tricks and tips for this. One is replacing the hose from the transom fitting that feeds the raw water pump with a clear one so you can see what the stream looks like, mainly bubbles or mainly water. You can also feed that hose directly from the garden hose. That would tell you if the problem is the pump/impeller or before the impeller back towards the drive.

I think the stickies topics at the top of this forum have the techniques to use for your type of drive, look around in there before you buy a new pump.

Re: NO water circulation in AQ231B

So I pulled out the raw water pump impeller, it was nice and soft, fins spread back out with no damage to them at all and the hozes going to are clear. My plan right now is that as a troubleshooting measure, I did replace it. I now have a brand new impeller in it and it is all lubed up with dish soap. I did look at the s shaped hose goin to the outdrive, and it is very soft. I was thinkin maybe it is getting pinched and not allowing water to flow? The hose is inexpensive enough that replacing it isn't going to hurt, so I think I will go ahead and replace it prior to next run, anyone else have any suggestions on what to do next?

Re: NO water circulation in AQ231B

Since your ordering an s hose, you may want to order some riser gaskets and pull the risers to inspect them and the manifold passages. they can get blocked up and cause overheating. What about the thermostat? While your at it...
You could do one at a time until you find the problem, but all those parts a maintenance items anyway.

Re: NO water circulation in AQ231B

this is an old thread hope the mods don't mind me bringing it up again however I still haven't resolved the issue. I pulled the raw water pump off today and haven't found anything that would indicate it isn't in good enough shape. I took the impeller out of it and it is in fine shape, springs back to normal and everything. I however did find that it had the soap I put into it last year to prime it still in, so it wasn't pumping it. I ran it for over a minute so I would expect it wouldn't be in there, but instead it full of water. Is there a way to tell if the body of the pump has gone bad? I would imagine it isn't something that goes bad so I am going to pull the shaft out of the middle and replace the rear seal on the pump, replace the cover gasket and seal, and when I install the impeller I will ensure I am spinning the pump in the proper direction to ensure the impeller is installed properly. I also am going to send the circulation pump out for rebuild soon, preventative and it will take it out of the equation.

I would appreciate any other suggestions. Also the pick up hose leading to the pump had water in it, so I would guess that part is functional, and I have checked it for leads and haven't found any, or obstructions.

Re: NO water circulation in AQ231B

Well not really to bring back an archived or old thread but felt it was worth posting my findings after trying to fix this problem all winter. I couldn't come up with any other better answer so I replaced the raw water pump with a whole new one. I purchased one that on the front is the F5B9 body style. It was a direct replacement for what was on there according to www.depcopump.com. They have a pump breakdown of all the volvo pumps and its replacement.

I am very happy to say that the replacement pump works wonderfully and the engine remained in 145 to 150 range on the instrument for about 10 mins worth of running. The lake was real choppy since it was very windy here so I didn't want to take it off the trailer but having it in the water and not over heating made me very happy! Thanks everyone for all of your suggestions. I am not sure what was wrong with the old pump but that was the fix to replace it. Now to get onto the interior.