Water tube in lower unit

[Speakrdude]

Is it even possible to misalign the water tube when reassembling an Alpha (Gen 1) lower unit?
I thought I read somewhere that is you run on the muffs and see a stream of water coming out of the weep, you are not connected.
That may explain a couple of other things...

 

[Don S]

Re: Water tube in lower unit

Sure it's possible. Just raise the drive and look inside, you will be able to see if it's in the pump or not.

 

[achris]

Re: Water tube in lower unit

Is it even possible to misalign the water tube when reassembling an Alpha (Gen 1) lower unit?
I thought I read somewhere that is you run on the muffs and see a stream of water coming out of the weep, you are not connected.
That may explain a couple of other things...

You need to see water coming from the weep hole at all times. If it get clogged up, clean it out.... (I usually drill them a little larger. Stops them clogging up)...

If you missed the water tube on assembly you will have all the water coming out of the prop and completely none coming from the exhaust reliefs..

Chris.....

 

[Speakrdude]

Re: Water tube in lower unit

I dont understand how the water would find it's way to the exhaust out the prop. Those two cavities dont connect, do they?
I Do, however, have water exiting from the relief ports.
As a matter of fact, on the hose at the shop, the risers are muchhh cooler. I was thinking that if the water tube was misaligned, the force of the water pressure (shop hose) was pushing it's way into the tube and on to the engine. Maybe not???

 

[achris]

Re: Water tube in lower unit

If you have water from the exhaust reliefs, at the side of the gimbal housing, then you got the water tube stabbed right....

The water pump, in the drive, is in the exhaust cavity, which exits through the prop.... If you missed the water tube, the water would just spill out of the top of the pump and into the exhaust cavity....

If you missed the water tube you could use a fire hose and no water would get to the engine!

 

[Speakrdude]

Re: Water tube in lower unit

Well thats reassurring. Now I have to figure out whats causing the overheat issue. Back to the basics. I suppose the next thing I will do is to check the amount of water the pump is putting out. I read that the alpha drive should fill a 5 gallon bucket in 20 seconds, while on the water, not on a hose. The system is a "half-closed" cooling system from Seakamp.
Thanks for your help gentlemen.

 

[achris]

Re: Water tube in lower unit

Water output is measured in 15 second time periods at exactly 1000rpm (shop tacho), and depends on the ratio of the drive... What engine you playing with?

While you were replacing the water pump impeller you didn't happen to have a look up into the bottom of the top box and check the condition of the water pocket cover did you? If the gaskets leaking, then you'll be getting air in the water stream... but only when the boat's run 'normally', on the water....

 

[Speakrdude]

Re: Water tube in lower unit

The engine is fresh rebuild, 5.7L, 90 model boat.
I replaced the complete pump, housing and all. I dont understand where you talking about. The old one wasnt melted but I replaced while I was in there.

 

[Speakrdude]

Re: Water tube in lower unit

And all new, Aluminum manifolds, risers.

 

[achris]

Re: Water tube in lower unit

The engine is fresh rebuild, 5.7L, 90 model boat.
I replaced the complete pump, housing and all. I dont understand where you talking about. The old one wasnt melted but I replaced while I was in there.

Once the lower unit was removed... (I assume you just removed the lower, not the whole drive) look up into the bottom of the top box (if it's still on the boat) and you'll see another plastic cover... THAT is the infamous 'water pocket cover'.....

If you have manual #15, then page 6A-8 has the water pump output test... You should pump 4qt in 15 seconds at 1000 rpm....

 

[Speakrdude]

Re: Water tube in lower unit

Sounds like your talking about #2 & 4?
Never even thought about checking that.
Isn't there a clear hose/bubble test for that?

 

[Speakrdude]

Re: Water tube in lower unit

Actually, I did have the complete drive off, while the long block was being built. Being how it's "infamous" does that mean it failed often?

 

[achris]

Re: Water tube in lower unit

Sounds like your talking about #2 & 4?
Never even thought about checking that.
Isn't there a clear hose/bubble test for that?
View attachment 148250

Yep.... Put a section of clear hose in the line from the transom... Run the boat normally (on the water, not a hose) and check for bubbles... See bubbles, leaking cover gasket...

 

[achris]

Re: Water tube in lower unit

Actually, I did have the complete drive off, while the long block was being built. Being how it's "infamous" does that mean it failed often?

If the engine's been run without water, yes... 'Without water' includes a failure of the pump in the leg to get water to the engine....

 

[Speakrdude]

Re: Water tube in lower unit

No, just test fired a couple of times.

 

[achris]

Re: Water tube in lower unit

No, just test fired a couple of times.

That's you... What about the owner? If the cover's leaking, I'd lay odds on the fact that he's not telling you something... Found that a lot when I had my shop... "It just needs a service"... But the engine's completely seized!!! "The service will fix that"... ... They think by not telling you the whole story you won't charge them for fix the obvious faults... :facepalm:

Chris.......

 

[Speakrdude]

Re: Water tube in lower unit

A question concerning the impeller installation. I was always under the impression that it didnt really matter which direction you bent the veins when you installed because as soon at the shaft turns, the veins will correct themselves, correct?

 

[achris]

Re: Water tube in lower unit

yeah, mostly... I prefer to set them in the right direction. Just had a little engine here for service and the impeller blades were all over the place. I don't rely on them sorting themselves out...