85 Johnson 150 V6 - No water at tell tale (or any where)

New to me outboard - had water out tell tale one day and zero water at tell tale the next. Didn't know when water pump had been changed so I replaced the water pump - impeller was still intact and didn't look too bad (all arms intact with nothing missing).

Sprayed hose up the water line and had water at tell tale - back flushed water through tell tale hose (using small nozzle on hose) and had water coming out water line. Ran muffs on lower unit while out and had water getting to impeller (intake screens are clean) although no water coming through impeller housing with just water pressure from hose.

Used air compressor to blow back through tell tale hose and can hear air come out water line.

Re-installed lower unit and still no water at tell tale.

I'm working under the assumption that since I had no water with old water pump and no water with new water pump that, obviously, something else is going on. But with the water path apparently not being blocked (water from hose seems to get through) - where do I go next? I've pulled the lower unit and checked the impeller installation 4 times now.

The last time I pulled the lower unit I hooked the muffs to it and turned the drive shaft by hand and it pushed water out of the impeller housing - so I'm confident that the pump is functioning.


I removed the tell tale plug from the engine block and ran the engine again - no water making it to the engine. I'm assuming by looking at the Johnson V6 water flow diagram that the tell tale is connected right away when the water enters the engine from the water tube.


So If I have no water there, does that mean that my water tube is messed up? Keep in mind that I had no water at my tell tale before I ever replaced the pump or removed the lower unit. I just started with the pump because I figured that was the most obvious issue.


Any assistance is GREATLY appreciated. Thanks.

Maybe the muffs are not working on this motor.

Take it to the lake and try it at the ramp if you don't have a barrel large enough. Make sure the pump's intake is submerged well above the cavitation plate.
Bill

It did work previously with the muffs and I have tried it at the ramp a couple times as well.

I'm not familiar with that motor but if it has an upper water tube grommet in the power head I would check it.
Bill

According to the parts diagrams it does. And that is exactly where I'm looking next.

The top of the water tube, in the mid-section, was my next target. So I dropped the lower unit again and it seems to be secure. I can pull on it and it doesn't move - seems like it's secure.
Then I went a step further with the lower unit - I attached a 4 inch section of garden hose to the drive shaft and put a hose clamp on it. Stuck a 7/8" drill bit in the other end. I put the muffs on and turned the water on about half way.
Put the bit in the drill and gave it a twist with my hand while starting the drill slowly. Drill was turning the drive shaft (in neutral of course - clockwise) and I had water coming out of the top of the impeller housing. I went one step further and attached a 3' section of hose to the impeller housing (garden hose fits right in the opening).
Held the hose up and started the drill again - again I had water pushing out the top of the hose.

THEN, I figured why not attach the hose straight to the water tube. So I cut a longer section of hose and the water tube fit snuggly right into the garden hose. Ran the drill again and within about 15 seconds I had water coming out the tell tale! That was with about 8' of hose and the water still on only about half way. The other place I had water was out of the exhaust tube - which is what I would expect with the motor not running and thermostats not open.


So - I know the pump works, I know the water path should be clear. The only difference is the motor is not running. I can't come up with anything that would be different with the motor running - other than water exiting the discharge holes above the prop - which I think is where it would come from of the thermostats opened and allowed water through the blocks.

I guess it's conceivable that I'm not getting the water tube into the impeller but that has been my main focus everytime I put the lower unit back on. I can get two fingers in to feel the water tube enter the top of the impeller housing - unless it's somehow dropping out before I get the bolts in.

The thing that's hauting me is why did I not have water with the old pump? If everything was working and I replaced the pump and it stopped working - then sure, I screwed something up. But it stopped working, I replaced the pump to try to fix it and it's still not working even though I think I've proved with this last test that the pump is functioning and the path is clear. I've looked at the instructions that came with the pump kit about a zillion times and I don't think I need any extensions or anything extra.


Seems so simple yet I can't seem to get it going. I've ordered a small inspection camera that I want to run up the water tube just to see whats up there. I may even be able to get it into the tell tale opening on the engine block. That's supposed to show up tomorrow so I think I'll keep the lower off until then.

A really appreciate all of the thoughts on this - keep them coming if any of this triggers anything else.

The camera showed me the water tube is clear and I was able to confirm that I was getting the water tube into the impeller housing correct.

Took it to the landing and couldn't get it started - BUT I had water coming out of the tell tale while cranking it over - could it be working? No.

Pulled oil line off VRO and went with pre mix. VRO seemed to be dumping oil - maybe why couldn't get it started. Went back to ramp, got it started but no water out tell tale and engine was hot (alarm doesn't appear to work).

So it appears that I can only get water out tell tale when motor is not running (during drill test or turning over for long period of time). Is my water being sucked somewhere it should be? Gasket issue somewhere before water gets to tell tale and engine block?

Engine seems to run pretty smooth - idles a little high but runs. I can do compression test and check pistons with my camera to see if any are clean like water is getting in. Could a gasket issue rob all of the water from the pump - seems odd.

I ordered new exhaust gaskets as well as thermostats and cover gaskets. Working on the hunch that the exhaust gaskets may be letting exhaust pressure into water system or letting water into exhaust. Last time I ran it felt like hot air coming out of tell tale - maybe exhaust.

Ill start there and see if I find anything. If not I'll move on to head gaskets.

Hello dsharretts,Did you ever get your cooling circuit to work?I have a 2 stroke 15hp Johnson and am having the exact same issue as you outlines above; waterpump is working fine, Water paths are clear and when I run the motor only air is coming out of the tell tale.What did you do to get it to work?

nirch said:

Hello dsharretts,Did you ever get your cooling circuit to work?I have a 2 stroke 15hp Johnson and am having the exact same issue as you outlines above; waterpump is working fine, Water paths are clear and when I run the motor only air is coming out of the tell tale.What did you do to get it to work?

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Nirch,

All I can tell you is I was out of ideas so I took it in to a shop. What they told me is there was a hunk of plastic that looked like it was left from the injection molding of the black housing/cover that might have been disrupting the flow.

I had that thing apart numerous times and never saw anything. Sorry - that's not going to help you much.

dsharretts said:

Nirch,

All I can tell you is I was out of ideas so I took it in to a shop. What they told me is there was a hunk of plastic that looked like it was left from the injection molding of the black housing/cover that might have been disrupting the flow.

I had that thing apart numerous times and never saw anything. Sorry - that's not going to help you much.

Click to expand...

Many thanks for your reply.
I did some further trouble shooting and it seems the water tube is leaking in the motor end.