?'s about cooling system..got it started--aq125

[2stroke1971]

I got my aq125 started, its in a 1984 bayliner. Ive been thru this motor quite a bit since I bought it, and finally got it fired.

Ive got a plastic 50 gallon drum that I cut down and IVe got the outdrive in that. Its running a bit rough, Ive got to tune it. It sounds like an exhaust leak, a bit like a lawn mower if you know what I mean. I put new exhaust gaskets on it so Im not sure about that, but I will get to that.

I left it idling for maybe 5 minutes at one point, revving it here and there. It seemed to bog a bit but again i will get that ironed out. The temp needle seemed ok...

So where the copper piping comes out of the bottom of the exhaust manifold, theres 6 inches of copper, then I have a big clear hose there that runs for about 10 inches, then its copper back into the strainer neck of the heat exchanger. The hose felt pretty warm, Id almost say hot. Is that normal? (again this is between the bottom of the exhaust manifold and the strainer neck.)

I though that fresh water comes flying through that pipe constantly...so wouldnt it stay pretty cold? My barrel of water was nice and cold at the end.

Also, the exhaust manifold was hot. I thought these stayed fairly cool on marine engines. Most worrisome is that there was only a trickle coming out of the exhaust port. The exhaust port was just out of the water, so normally, water should be gushing out of there along with the exhaust right? I did not observe bubbles in my clear hose, but Im not sure the water was really moving thru. Again, Id expect that to stay cool.

So, Im thinking seawater pump issue, but Ive been thru that. I put a new front seal on it, and a new cross piece (coupler). How long should the seawater system take to prime if its bone dry?

One more thing..when you open the cap on the strainer neck of the heat exchanger, what part of the system are you looking into? Why is there even a cap there? I thought coolant went there, and I actually poured some in, and it showed up immediately down there in my clear hose headed to the exhaust manifold. I cant fathom why there would be a cap there or why what I poured down that neck made it into the seawater system.

(Im not talking about the radiator cap type cap, I know thats for the intake side system. )

I dont want to try and tune it in or even run it anymore until I figure this out.

 

[Don S]

Re: ?'s about cooling system..got it started--aq125

Did you replace the impeller when you went through the raw water pump and did the front seal? If not, do it.

Since you are running in a barrel, you could be sucking air and not water due to a corroded off hose connection on the drive. Very common problem with Volvos. You can't usually see the problem but if you grab the hose and move it, the end of the nose connection falls apart.
Problem found.

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Don:
The previous owner told me he had put an impeller in last season, and it was pliable and nice looking so I believe him.

I read the impeller spins clockwise, so inserting the impeller I placed it so that the fins hooked backwards as it spins, is that right? Or should they hook forward? I found that I could spin the impeller by hand although not easily when the fins hooked backwards.

So if the infamous gooseneck or elbow is bad could that keep it from priming at all in a bucket? I guess that problem is less aparrent in a lake since the leaky part would be under water until you get up on plane right?

There are two large hose clamps on the exhaust hole where the manifold goes into. I dont know what is supposed to be there at that joint, but I tightened the clamps pretty hard, Im wondering if I could have pinched off the water exit ports since they are around the outside of the exit. I doubt it since the pipe the exit of the manifold goes into is pretty rigid I think. And I should add that I did flush the manifold with a garden hose when I had it off, and it flowed quite well out the exit ports, with no back pressure at my hose connection to the copper pipe

I suppose I should pull that elbow and give it a look see. Im quite certain now that I am getting NO flow thru the seawater system. I also understand now that the cap on the heat exchanger IS the seawater system, its for cleaning the basket strainer, which I might add, is absent on this boat!

 

[Don S]

Re: ?'s about cooling system..got it started--aq125

I read the impeller spins clockwise, so inserting the impeller I placed it so that the fins hooked backwards as it spins, is that right?

As soon as you turn the engine, the vanes will flip the right direction, even if you turn it the wrong way.

So if the infamous gooseneck or elbow is bad could that keep it from priming at all in a bucket?

Absolutely, that's why I mentioned it.

There are two large hose clamps on the exhaust hole where the manifold goes into. I dont know what is supposed to be there at that joint, but I tightened the clamps pretty hard, Im wondering if I could have pinched off the water exit ports since they are around the outside of the exit

Post a picture, not sure exactly what you are referring to.

I suppose I should pull that elbow and give it a look see

Yes, do that, instead of these long novels.

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Pulled elbow. Minor pitting, a bit of the flange gone, plenty of clamping area left. Seal was bad.

Got new seal, cleaned up surfaces. Still no pumping.

Pulled rubber hose from steel tube where raw water enters thru transom and added another small hose and attempted to pull from a gallon jug in the bilge area to bypass outdrive all together.

It was flowing at a decent rate briefly,but motor died, and it would not flow again after refilling jug. pulled the straw-hose from the jug while running -what water was in the hose dribbled back out.

Felt the end of the hose while running. .vacuum felt weak, like barely there. Points to a pump problem.

If the system is dry, how long should it take to start pumping water out of the exhaust? there is no need to "prime" the raw water system, right?

Wonder if the heat exchanger could be clogged.

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

did some more testing. removed heat exchanger to isolate pump. Had intake to pump in a gallon jug, had output pipe staring me in the face. Thats it, tube in a jug to pump, tube out of pump to nowhere.

Ran the motor briefly, twice, even revving it a bit. NO flow. I expect I should have been getting sprayed in the face, but nothing.

Heat exchanger seems to flow thru well, I can blow thru it easily so its not clogged.

 

[captmello]

Re: ?'s about cooling system..got it started--aq125

Well, you found the problem. Start pulling the pump. Check your impeller. Is the key in the groove of the shaft? The pump should not need priming to start pumping. Pull the cover off the pump and turn over the engine, don't start it. does the impeller spin?

You also better get a strainer before something clogs up the heatexchanger.

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Got the pump off, the woodruff key was in place. I guess the impeller is bad, there are no cracks or broken fins, its pliable. It does sort of have a hook to it, you know, all the fins are bent at rest a bit-you can tell which way its been spinning from that.

Ive been playing with it. I can blow thru one port and out the other when its assembled, I figure it should be almost air tight between the two ports depending on position of the impeller.

So, buy an impeller, sure. Is there anything that can go wrong with the housing that would make it fail? The bushing on the cover side has a little slop in ot, not too bad, but I dont have a blind side puller to replace that one.

 

[jerryjerry05]

Re: ?'s about cooling system..got it started--aq125

Got the pump off, the woodruff key was in place. I guess the impeller is bad, there are no cracks or broken fins, its pliable. It does sort of have a hook to it, you know, all the fins are bent at rest a bit-you can tell which way its been spinning from that.

Ive been playing with it. I can blow thru one port and out the other when its assembled, I figure it should be almost air tight between the two ports depending on position of the impeller.

So, buy an impeller, sure. Is there anything that can go wrong with the housing that would make it fail? The bushing on the cover side has a little slop in ot, not too bad, but I dont have a blind side puller to replace that one.

The pump has an eccentric cam in ther bottom of the pump these wear out.Find a parts diagram.It fits between the hoses on the bottom of the pump(I think).It's held in place with a screw from the outside.(been a while )
The manifold could look brand new and still be bad.
If you take it off and hook a hose to it then flush, it should flow as much water out as you can put in.They rot and block no acid soak or rodding is gonna help.
The two caps 1seawater strainer the other radiator cap(exchanger).
The motor runs rough till it warms.Make sure no water is in the fuel system.
Fill out the profile it helps to know what part of the country your in.Salt or fresh.J

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Yes, Ive seen that...sort of a scraper between the ports
The cam that is. I will get a new one of those along with an impeller.Thanks!

This ones been is salt most of its life. Chesapeake bay area.

 

[jerryjerry05]

Re: ?'s about cooling system..got it started--aq125

Yes, Ive seen that...sort of a scraper between the ports
The cam that is. I will get a new one of those along with an impeller.Thanks!

This ones been is salt most of its life. Chesapeake bay area.

Salt water will cause all kinds of nasty stuff. Under the radiator cap is a heat exchanger it causees it to plug up if not rinsed with fresh water.
The chesapeake isin't as bad as some areas but it will still eat the exchanger and manifold.
I lived in Pasadena for 10years and found Cobe Marine was the best Volvo guy around(I think the store is still there but maybe not Bill) J

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Hell yeah, Cobe is great. Just turns out that they came up first on the list as to the nearest dealer and Ive spent alot of $$ there in the last few weeks!

This boat was used in Virginia, but it spent most of the last 12 years in a shed until the previous owner made an attempt at renovating it.

Lots of twists and turns on this one.

I went to get a new impeller kit, and I took the old one and the pump with me. I asked for the impeller, and when he brought it out, I took it out of the box to look at it, and it was a good bit smaller than the one that was in there.

He said, after checking and double checking the numbers, "Are you sure thats the one that came out of there?" I said yes, and so he then matched it up by measurements. No Volvo listing matched my impeller. He came out with a sherwood kit, and the impeller matched my impeller exactly. BUT, out of the gaskets included with the kit, the ones that were shaped right were too big.

After more discussion with the parts guy, we decided that the previous owner had the WRONG impeller in there. He said he never knew a Volvo that used a sherwood impeller, so he brought out the Johnson pump unit again, and the gasket included in that one fit just right. Stranger things have happened I guess but I suppose that had something to do with the lousy pumping. There also were NO seals at the pump connections, only permatex.

Further, the exhaust pipe that connects the exhaust manifold to the outlet pipe was in actuality a piece of air duct wrapped around with some hose clamps. I heard an exhaust leak, (Turned out to be the makeshift pipe) and while I was feeling around for it, I got zapped by one of the plug wires so I guess a new set of those is in order. As finicky as it was about the plug gap, a new set of wires ought to do it well.

I have not as yet tried the new impeller, just re assembled everything again this afternoon.

 

[jerryjerry05]

Re: ?'s about cooling system..got it started--aq125

Sounds like you got your work cut out for you.
Those plug wire from Volvo were around $100 last I knew. Use the set for a Volvo car.J

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Put new plug wires on, and it fires RIGHT up now.

But STILL NO PUMPING!

The seawater pump has a new impeller lubed up with glycerine, new front seal, new seals for inlet and outlet pipes, and a new cam, and a new cross piece. NOTHING. I verified that the pump IS spinning when the motor cranks.

The exhaust port is just out of the water, theres no water coming out of it.

I even tried my straw in a jug bit to bypass the outdrive, and NOTHING.

Put my finger on the end of the hose while it was running, no suction. I assume it should have some right? I mean this thing is supposed to pull water all the way thru the outdrive and out the pipe, so it should be making some suction right?

The pump did have some wear in the housing, on the inside of the cover, and then the back wall of the pump, there was some grooves worn in it...I wonder if thats why its not making any suction. If you can imagine the blades of the impeller making a seal against where they run...does the sided of the impeller also have to seal? If so there may be some blow by from those grooves.

I could mill the inside of the cover down flat easily, but the inside if the back would be harder.

I just dont know how one of these is SUPPOSED to work, but this aint doing it.

 

[captmello]

Re: ?'s about cooling system..got it started--aq125

Wow, what a pita. The impeller does need to fit tightly against all sides to have good suction. Can you take a pic of the grooves worn in the housing? Maybe you can get an opinion from one of the pros.

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

So generally speaking,

How "squashed" should the impeller be at the cam area? Should the vanes be bent over tight and flat against the center of the impeller, or just slightly more bent than the rest of the impeller? There was some confusion as to just which impeller goes into my pump...the one I removed had the vanes squashed pretty darned tight between the ports, and the new one I got was noticeably smaller.

Im thinking about trying my old impeller which is larger and squashes almost flat at the cam area. The difference would now be it has a new cam and proper seals at the inlet and outlet. I swear, even before the new cam and new seals, the old larger impeller produced at least some weak suction.

This new smaller impeller wasnt doing squat.

 

[starsnstripers]

Re: ?'s about cooling system..got it started--aq125

If the old impeller was wrong it may have worn the cover, you want to fix/replace that cover grooves don't help the suction. Do you have the seals in the pipe on the suction side? Sounds like a suction leak to me.

 

[captmello]

Re: ?'s about cooling system..got it started--aq125

Here is a pic of mine. You can see the fins are bent over more at the cam, between the two hoses. I have a different pump but this may give you an idea of how it should look. Also note the impeller is flush with the front edge of the housing to give a complete seal.

[/IMG]

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Thanks guys!

CaptMello, that looks about right as far as my smaller "correct" impeller.

I took the cover from the pump into work today and decked it until there were no more lines. The scoring was pretty deep towards the center. the rear had SOME lines, but not that bad....should jsut get a new pump when I can,

I put it back together. I got minimal results from my straw in a bucket approach, and I still didnt feel any suction but I put it all together and lo and behold, it started pumping thru the outdrive from my bucket.

I let it run a good while, the temp looked pretty good. The carb has issues, it wont take a gun of the throttle, it bogs, but if you ease it on it revs fine. After a while the barrel of water got pretty warm so I shut it down.

Im gonna do the rest of the tuning somewhere where Ive got a bigger supply of water!!!

On to the next issue~!

Thanks again!

 

[2stroke1971]

Re: ?'s about cooling system..got it started--aq125

Oh yeah as for the plug wires. Heh heh. I am an economical person. I went to the pull-it-yourself junkyard and found a VERY nice set of import style NGK wires. SUPER insulators down by the plugs so there will be no jumping of spark. Dirt cheap too.

Believe me, I was checking out the old volvos they had there! LOL...those 4 cylinder blocks look familiar....at least the fan pullys! Heh heh.

Hmmm....fuel injetction system...bet one of those intakes would bolt up.