Mercury 3.3hp No Tell Tale Water

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Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Mercury 3.3hp No Tell Tale Water

Post by Polybus »

Howdy,

I've just finished a rebuild of a little Mercury 3.3 2 stroke, about 2000 model.

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 with a drill - Water came out of the top of the Pump Housing.
2: Pulled the whole Power Head off, and 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 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.

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.

Is it possible the agitation in the Test Tank water isn't allowing the engine to suck up water? I guess it's [possible, but I've never had that issue with any of the many Seagulls I've tested in that same tank.

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.

Can anyone help?

Thanks.
Last edited by Polybus on Wed Aug 18, 2021 9:26 am, edited 1 time in total.
Silver Surfer
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Location: Sunny South Shields.

Re: Mercury 3.3hp No Tell Tail Water

Post by Silver Surfer »

Just from personal experience-I've had 2 Seagulls and a Mercury 20HP that wouldn't squirt out of the Tell-Tale if I left the Propeller on in my Test Barrel. If nobody comes up with an alternative answer, it might be worth a try. 8)
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

G'day Silver Surfer,

A good thought, thanks, but I've tried it in Neutral, so the prop is not spinning. I've also tried it with the prop off - No joy.

Today I'm going to pull the power head off again and see if there is anything in there that I have missed.

But I'm clutching at straws - I am stumped.
Last edited by Polybus on Wed Aug 18, 2021 9:26 am, edited 1 time in total.
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

G'day Again Silver Surfer.

Your suggestion keeps playing on my mind - the fact that the only time I can't get it to work is with the motor running (with powerhead off and spinning with a drill it appears to work OK - at least up to the level of the powerhead).

As I mentioned previously, I have tried it in Neutral, and without the prop with no luck - but I notice there is quite a bit of turbulence in the test tank due to the exhaust, so maybe that is causing an issue.

I'm going to take it down to a lake/river tomorrow to see if that makes any difference (although pretty much everyone around here is locked down so I may have to run the gauntlet - I am allowed out to perform "work" that I cannot do at home - so this sorta kinda qualifies.

I also cannot figure out why there appears to be exhaust coming from the tell tale pipe (the powerhead gasket is new/good)
Silver Surfer
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Joined: Thu Mar 17, 2016 10:10 pm
Location: Sunny South Shields.

Re: Mercury 3.3hp No Tell Tale Water

Post by Silver Surfer »

Another stupid suggestion... Bit of thin wire/flimsy coathanger/welding rod, and poke it up the Tell-Tale hole, and pipe, and everywhere it 'might' have a slight blockage? Clutching at straws myself here.
It won't be the first time I've heard or seen a bit of crud or gasket sealer stuck, after a bit of 'fettling'.
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

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

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 at the top, 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??!?!?!!? :twisted:
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

Just ran it in the River - still nothing!!!

I'd like to run it on a boat - but I don't have one at the moment.

I'm out of ideas......
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Charles uk
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Re: Mercury 3.3hp No Tell Tale Water

Post by Charles uk »

Is it the right impeller?
Make it idiot proof and someone will make a better idiot.
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

I hope so!!

It works when the drive shaft is spun by a cordless drill.

Looks identical (but newer) to the old one I took out.

Seems to fit in the Water Pump OK - not loose around the edges.

I reckon its the right one.
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beerjam
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Re: Mercury 3.3hp No Tell Tale Water

Post by beerjam »

Do you have any pictures, at various stages of assembly / disassembly, to help us visualise the situation?

Cheers, Mark
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Charles uk
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Re: Mercury 3.3hp No Tell Tale Water

Post by Charles uk »

Does it have a thermostat?
Make it idiot proof and someone will make a better idiot.
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

Thanks for your input Charles - No Thermostat.

OK - today - photos (D'oh. Should have done that much earlier)
Polybus
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Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

Photos and Videos are a bit big to upload here, so here is a link to them on my Google Drive.

Hopefully the names Describe the content.

https://drive.google.com/drive/folders/ ... sp=sharing

Enjoy.
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beerjam
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Re: Mercury 3.3hp No Tell Tale Water

Post by beerjam »

You say that you are running it with water 10 inches above the anti-cavitation plate, is that not a bit deep? Could back pressure from the exhaust be causing a problem with water flowing out of the block? That might also account for smoke from the tell-tale.
Cheers, Mark
Polybus
Posts: 37
Joined: Sat Oct 21, 2017 3:42 am
Location: Port Douglas

Re: Mercury 3.3hp No Tell Tale Water

Post by Polybus »

Exhaust backflow causing the problems - brilliant thought!!

I'll start having a look at that.

Unfortunately I'm away from home for 2 weeks working out in rural NSW - as soon as I get home I'll start investigating this.

Great thought - thanks!
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