Mercury 3.3hp 2 Stroke - No water through Tell Tale.

[Polybus]

G'day,

I've just finished rebuilding my 2000 Model Mercury 3.3 2 Stroke (a rebaged Tohatsu 3.5hp I believe) - I bought it as a seized wreck.

Everything works OK - except the Tell Tail. It runs - Gears (Forward & Neutral) work - all seems good, except the Tell Tail. As part of the rebuild I put in a new Impeller/Water Pump kit.

Trouble Shooting so far.

1: Pulled The Gear Box off - dipped it in water, and turned the Drive Shaft (Clockwise) with a cordless drill - a good flow water came out of the top of the Pump Housing.
2: Pulled the whole Power Head off, and placed the entire leg into the Test Tank - turned the Drive Shaft with a drill - water came out of the top of the water pump tube, and started filling the water galleries.
3: Pumped water up into the Tell Tail pipe (Power Head still off), and watched it come back out of the hole at the bottom of the block's water galleries.
4: Reassembled motor again - run it in test tank - nothing - no water comes out of tell tail.
5: I have probed/cleaned the holes in the water galleries leading to the chamber around the cylinder.
6: With the motor sitting upright (as mounted on a transom) if I inject water into the Tell Tale pipe - a second later it will flow out of the Exhaust hole on the bottom of the leg.
7: With the Power Head off, and upside down - I can pour water into one (of the three) holes leading to the water jacket around the cylinder - once the chamber is full with water, I can see it overflowing through all three holes.
8: I have gently drilled out the actually Tell Tale nipple - it is clear.

Any suggestions as to why?

I was wondering if I have to prime the water pump, but when I test it with a drill, it self primes without a worry.

Other observations...

1: Smoke/Exhaust comes out of Tell Tail Pipe at times
2: I have tried the Impeller with the vanes oriented both directions
3: Test Tank water is well above the Cavitation Plate - at least 10 inches above it.
4: I have visually confirmed the Water Tube is fitted into the top of the water pump.

So in summary:
- From the drill test, I can see that the impeller is working - the water pipe is clear - and water is getting up to at least the water galleries at the base of the Power Head.
- From injecting water into the the Tell Tale - and from visual inspection - and from probing/prodding the holes - I can see that the water galleries around the cylinder seem to be clear
- From filling the water jacket around the cylinder - and seeing water coming from all three holes - I believe they are all clear.

- The Pump/Pipe/Leg sections work find (as per the drill test) - there must be something screwy going on with the power head water galleries that I'm not understanding....

I cannot understand why the water is not flowing through the whole system.

Can anyone help?

I'm wondering if the turbulence in the test tank from the exhaust is preventing it sucking water into the water pump - I have tried it both in Neutral and in Forward, and also tested it with the prop removed, but the turbulence seems to be coming from the exhaust bubbles rather than the prop.

My next step is to take it down to the River/Lake and test it down there....

Unless someone has any other ideas in the meantime ...... I'm stumped.

 

[Refueler]

My first question would be : Why did it seize ?

Maybe - you just found out why ?

As to 'smoke' out of tell tale ...... I would assume that's either steam or overheating block .... I had similar with my Mariner 3.

Turned out to be crud in the small pipe at exit .... the crud was being pushed to near close the exit ... it took quite a few attempts with wire probe to break it and get it clear ...... then slowly the water flow increased ...

 

[Polybus]

I'm convinced the Tell Tale outlet and Pipe are clear.

I have drilled out the outlet itself and water will flow through it OK when I fill the water jacket with water and tilt the Tell Tale down.

And the pipe is clear with both air and water going throw it easily.

Not sure why it seized.

 

[Graham376]

I've found test tanks/dustbins sometimes need a higher water level than when engine is dinghy mounted.

 

[Polybus]

I've got the leg very deep in the water of my test tank (a water drum), but I'm thinking alo g the same lines as you.

I'm going to take it down and test it in the river tomorrow - see how that goes.

 

[VicS]

I've found test tanks/dustbins sometimes need a higher water level than when engine is dinghy mounted.

With the water 10" above the anti-ventilation plate it should be more than deep enough

 

[VicS]

I've got the leg very deep in the water of my test tank (a water drum), but I'm thinking alo g the same lines as you.

I'm going to take it down and test it in the river tomorrow - see how that goes.

A good idea.

You seem to have explored all the possibilities .
Except
You don't seem to have tried connecting a hose to the water tube while the gearcase assembly is off. If you do that you should get water coming out of the tell-tale and falling down the inside of the exhaust housing from the outlet from the engine.

Despite your tests with the drill suggesting otherwise I think there is a problem with the pump.

 

[Polybus]

What are you thinking could be the problem with the pump? (New impeller - New Gaskets)

As you can tell, I have just assumed it is OK because I can see its pumping water when the drive shaft is rotated with the drill.

The water flow looks pretty good, but perhaps not as much volume as expected.

But Im stumped..... I'd value your thoughts.

I wonder if the impeller is slowly rotating on the shaft, thus decreasing water volume. I know the little lo King pin is in place, but I guess it could be slipping.

Another thing to check tomorrow.

 

[Graham376]

What are you thinking could be the problem with the pump? (New impeller - New Gaskets)

Not a usual fault but pump housings can wear, leaving too much clearance around the impeller.

 

[VicS]

What are you thinking could be the problem with the pump? (New impeller - New Gaskets)

As you can tell, I have just assumed it is OK because I can see its pumping water when the drive shaft is rotated with the drill.

The water flow looks pretty good, but perhaps not as much volume as expected.

But Im stumped..... I'd value your thoughts.

I wonder if the impeller is slowly rotating on the shaft, thus decreasing water volume. I know the little lo King pin is in place, but I guess it could be slipping.

Another thing to check tomorrow.

I would definitely check the impeller and the drive key. You would not be the first tp lose the key

 

[Polybus]

OK - this is getting a bit silly now......

As per VicS suggestion......

I pulled off the Gear Box yet again and connected a hose to the bottom end of the Water Pipe, the end that slips into the Water Pump housing.

I turned on the hose and was greeted by the lovely sight of a nice, solid stream of water coming out of the Tell Tale tube, and a quantity of water coming down the inside of the Leg/Exhaust Housing.

So I guess that tells me there are no blockages anywhere, and all of the water cooling passages are clear and allowing water to flow.

I did a couple of little experiments to see how low I could have the water pressure from the hose while still getting a good stream of water from the Tell Tale tube - to my surprise, the pressure required to get a good solid stream from the Tell Tale hose was very low.

So now I know all the passages are clear from bottom to top - it MUST be the pump......

So open up the Water Pump housing again.

Impeller looks good - Tick.
Rotating the right way - Tick.
Reinstalled Impeller, making 110% sure the Drive Key is in place - Tick.
Rotated Drive Shaft by hand, holding Impeller to see if it slips - No slip, seems to be locked fast with Drive Shaft.
Test again with a Cordless Drill in the Test Tank - Perhaps it was my imagination, but I thought the stream of water was much bigger than in previous tests (ah ha - thinks I - it was the Drive Key all along)

Now - 100% confident it would be working this time - I put it all back together:
Made 100% sure the Water Pipe slid into the Water Pump Housing.

So back into the Test Tank.

Nothing.

No Tell Tale.

(And the engine gets quite hot, so I am pretty sure there is no water flow).

High Revs in Neutral - Nothing
Low Revs in Neutral - Nothing
High Revs in Gear - Nothing
Low Revs in Gear - Nothing.

(all with the propeller removed)

I can see the the shaft rotates when I run it in gear - so the Impeller must be turning.

The only thing left that I can possibly think of to do is test it in a Lake/River - I was going to do that today - but our wonderful Government has decided, in its great wisdom, to lock us all up in our houses, and (seriously) they have started to put people in jail if they are caught out of their houses without a "reasonable" excuse - I know most people he on this forum would consider testing their rebuilt outboard a reasonable excuse - but I'm not sure they Police would.

Why isn't this stupid thing working??!?!?!!?

 

[Mark-1]

OK - this is getting a bit silly now......

As per VicS suggestion......

I pulled off the Gear Box yet again and connected a hose to the bottom end of the Water Pipe, the end that slips into the Water Pump housing.

I turned on the hose and was greeted by the lovely sight of a nice, solid stream of water coming out of the Tell Tale tube, and a quantity of water coming down the inside of the Leg/Exhaust Housing.

So I guess that tells me there are no blockages anywhere, and all of the water cooling passages are clear and allowing water to flow.

I did a couple of little experiments to see how low I could have the water pressure from the hose while still getting a good stream of water from the Tell Tale tube - to my surprise, the pressure required to get a good solid stream from the Tell Tale hose was very low.

So now I know all the passages are clear from bottom to top - it MUST be the pump......

So open up the Water Pump housing again.

Impeller looks good - Tick.
Rotating the right way - Tick.
Reinstalled Impeller, making 110% sure the Drive Key is in place - Tick.
Rotated Drive Shaft by hand, holding Impeller to see if it slips - No slip, seems to be locked fast with Drive Shaft.
Test again with a Cordless Drill in the Test Tank - Perhaps it was my imagination, but I thought the stream of water was much bigger than in previous tests (ah ha - thinks I - it was the Drive Key all along)

Now - 100% confident it would be working this time - I put it all back together:
Made 100% sure the Water Pipe slid into the Water Pump Housing.

So back into the Test Tank.

Nothing.

No Tell Tale.

(And the engine gets quite hot, so I am pretty sure there is no water flow).

High Revs in Neutral - Nothing
Low Revs in Neutral - Nothing
High Revs in Gear - Nothing
Low Revs in Gear - Nothing.

(all with the propeller removed)

I can see the the shaft rotates when I run it in gear - so the Impeller must be turning.

The only thing left that I can possibly think of to do is test it in a Lake/River - I was going to do that today - but our wonderful Government has decided, in its great wisdom, to lock us all up in our houses, and (seriously) they have started to put people in jail if they are caught out of their houses without a "reasonable" excuse - I know most people he on this forum would consider testing their rebuilt outboard a reasonable excuse - but I'm not sure they Police would.

Why isn't this stupid thing working??!?!?!!?

I admire your methodical work on this.

Is there any way that, only when the gearbox is connected, the join between the water pipe and gearbox is blocking/kinking whatever? From your tests above perhaps not.

Try *lowering* the water in the test tank and experimenting with the angle of the engine? Try a completely different test tank - just manually stand it a bucket or something as a sanity check?

 

[LONG_KEELER]

Is there any way that, only when the gearbox is connected, the join between the water pipe and gearbox is blocking/kinking whatever? From your tests above perhaps not.

I had the same problem.
Worked fine with the cordless drill.
Turned out to be the above problem . Not easy to check.

 

[Polybus]

Just tested it in the River - standing on a boat ramp with the engine at various depths - Nothing.....

Maybe I need to test it on a boat - but I don't have one at the moment.

Mark-1 and Long_Keeler:

Thanks for the input - my gut feeling is there is no issue with the water pipe blocking - as mentioned above - I have tested it with the Water Pipe inserted into the Water Pump and I can see a good flow of water coming out of the top of the pipe, where it fits into the Water Galleries.

BUT.......

Quite clearly - I have reached a point where I have no clue what's going on - I have asked for help - I would be a fool to ignore your help. ie: Why ask for help if I am not going to listen when people offer it?

So I will run with your suggestion (Mark-1) and past experience (Long_Keeler), get the gear box off yet again - pull the Water Pump apart and see what I can see..... see if anything could be blocking the entry to the pipe.

This may never get solved!!!

 

[Mark-1]

Just tested it in the River - standing on a boat ramp with the engine at various depths - Nothing.....

Maybe I need to test it on a boat - but I don't have one at the moment.

Mark-1 and Long_Keeler:

Thanks for the input - my gut feeling is there is no issue with the water pipe blocking - as mentioned above - I have tested it with the Water Pipe inserted into the Water Pump and I can see a good flow of water coming out of the top of the pipe, where it fits into the Water Galleries.

BUT.......

Quite clearly - I have reached a point where I have no clue what's going on - I have asked for help - I would be a fool to ignore your help. ie: Why ask for help if I am not going to listen when people offer it?

So I will run with your suggestion (Mark-1) and past experience (Long_Keeler), get the gear box off yet again - pull the Water Pump apart and see what I can see..... see if anything could be blocking the entry to the pipe.

This may never get solved!!!

You've ruled out any possible problem with the outboard so we're the point where we need to check your eye function. Maybe you have some rare cognitive disorder that prevents you seeing moving water from a running engine. Turn on a tap and run your car engine. Does the water dissapear? ?

Or perhaps the outboard is haunted? Get a vicar involved?

Have you angered any witches recently?

(I'm not sure how helpful I'm being.)

 

[Kinsale373]

I've just completed a rebuild of one of these a few weeks ago.

Have you taken off the head to clean the waxy grease that builds up in the cooling ducts? This is a very common problem . Easy to do and I have never had to replace the gasket.

On occasions during re assembly, I not properly located the pipe that carrys water from the top of the pump to the head, Is this fitting well into the top of the pump. ?

Is the tiny circular pin that sits on the flat on the drive shaft and provides the mechanical link to drive the pump impeller in place? If not the impeller can drive a bit but will slip when under any pressure.

Kinsale 373

 

[Polybus]

I had considered haunted..... currently researching Exorcism for Outboards - its a work in progress.

I have made 110% sure the Water Pipe is mounted securely in the top of the water pump - so that's not the problem.

Have checked the impeller is not slipping under pressure.

The head - OK that is something I have not looked at - so tomorrow.....

Off with its head!!!!

 

[Refueler]

One thing I note with my J 3 ... the amount of water out of Tell tale is minute compared to all other engines I have ... and on checking with O/Bd service guy here - he said it was normal.

 

[VicS]

I had considered haunted..... currently researching Exorcism for Outboards - its a work in progress.

I have made 110% sure the Water Pipe is mounted securely in the top of the water pump - so that's not the problem.

Have checked the impeller is not slipping under pressure.

The head - OK that is something I have not looked at - so tomorrow.....

Off with its head!!!!

Your test with the hose connected to the water tube together with some of the other things you have tried do not indicate any problem with flow through the engine. (That was the purpose of the test on the hose)
You must find out why there is no flow from the telltale. That indicates whether or not the pump is working properly..................... It is clearly not.

A couple things go through my mind.
Is the water tube correctly located at it top end? (I'm pretty sure from what you have said that it is)
Is the water tube holed? ( I'm sure you would have noticed by now)

I am now wondering about the parts making up the pump. There is very clearly something wrong here.

You fitted a complete pump overhaul kit according to #1 but I am wondering if you have the wrong impeller, (or the wrong housing.)

 

[VicS]

One thing I note with my J 3 ... the amount of water out of Tell tale is minute compared to all other engines I have ... and on checking with O/Bd service guy here - he said it was normal.

I take it by J3 you mean a 3 hp Johnson
If so is it a genuine 2 cylinder Johnson (1997 or earlier) or a rebadged single cylinder Tohatsu ( 1998 onwards)
If the latter then it is pretty much the same as the OPs Mercury.