Cooling Trouble / Diagnostic for top water tube grommet failure?

Good Trout To You Sir

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May 22, 2018
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Motor: E3RC (1987 2.5HP).
Symptoms - motor is overheating per "touch test" when pushed greater than 1/3 throttle. Cools very quickly once brought to slow speed. When on the water, sometimes I hear a "clinking" sound in midsection, leading me to question whether water tube is vibrating enough to strike inside of exhaust housing. [ Is this a key observation? ]
Visually difficult to assess tell-tale. This model emits spray from small holes on back of exhaust housing. In barrel test, see spray emitting at low speeds. Would expect to see higher pressure spray from tell-tale at greater speeds. Unclear if that's occurring.
Inspection of engine block, tubing, wire insulation: all good. No signs of black paint loss around block. (Perhaps this means little.)
Water pump assembly approx. 10 months old. Just inspected impeller. Looks good. Tested pump action in bucket of water with drill to turn drive shaft. At low RPMs, volume of water exiting pump seems impressive. Ruling out pump failure for now..
Improper transom height leading to ventilation also ruled out for now. Motor still overheats when mounted for deeper running.
*** Is there a slick diagnostic anyone has used to assess likelihood of fault at top water tube / grommet connection point? Sure do wish to avoid removing exhaust housing for visual inspection if I can avoid it. ***
Your thoughts appreciated!!!!!
 

thatone123

Banned
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Mar 7, 2009
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Unfortunately this is a "Live and Learn" deal and as far as I know the lower leg unit must be removed. I have worked on lots of 9.9/15 and only came across this problem once not too long ago.
 

Good Trout To You Sir

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May 22, 2018
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Have removed the lower unit and am staring at copper water tube.(Have NOT removed the midsection.)
At the water pump end, tube has some play in it. To those who are veterans of the upper water tube grommet issue, how much free movement of tube lower end would you expect to see?
If upper grommet is in good condition, should water tube be relatively rigid?
Also - what are chances water tube has worked its way through the upper grommet higher than usual -- with result being tube end closes to pump is not seating fully inside the pump grommet?
Thanks!
 

F_R

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Jul 7, 2006
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Where are you touching it to feel the heat? I'm not real familiar with that model except for how it has evolved from older motors. In that respect, there are certain areas that get blazing hot. That is normal. Perhaps there is nothing wrong with your motor (?).

The water tube fits in a rubber grommet at the upper end, so it would not be rigid as you are expecting.
 

Good Trout To You Sir

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May 22, 2018
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Where are you touching it to feel the heat? ....
The water tube fits in a rubber grommet at the upper end, so it would not be rigid as you are expecting.

F_R: I'm touching motor on underside of mount where midsection bolts to powerhead. Picture shows the area from underside perspective....where I perform my touch test. (On the water it's impractical for me to remove cowling and touch the block directly.)
When advanced past 1/3 throttle this metal gets MUCH than 160 degrees. Is that normal?
I'm sensitive to overheat potential b/c motor had some melted wire insulation when I acquired it as a non-runner. Since there was zero pump activity at acquisition, I believed that new pump assembly had alleviated any overheat issue. Pump action seems pretty good, but that doesn't mean flow is good.
Questions:
Without unbolting head from midsection, is there a diagnostic for water tube UPPER grommet collapse --- such as fishing wire up copper tube?
How could I determine that the anchor point within the UPPER grommet has changed -- with the effect that tube has moved higher than designed? If that tends to happen, I could understand how tube lower end may not seat properly inside LOWER grommet on water pump -- with effect that water pump pressure could further push tube out of alignment and reduce flow to the block.Is there a way to assess the proper copper tube position without removing midsection?
I appreciate your help....thank you!

E3RCUA (Connection Pt - Pwrhd to midsctn).jpg
 

F_R

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As I said, I don't have direct experience with that model. But the parts book shows a double bend at the upper end of the tube. Going by that, I sort of doubt the tube can move up and down.
 

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Vic.S

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F_R: I'm touching motor on underside of mount where midsection bolts to powerhead. Picture shows the area from underside perspective....where I perform my touch test. (On the water it's impractical for me to remove cowling and touch the block directly.)
When advanced past 1/3 throttle this metal gets MUCH than 160 degrees. Is that normal?
I'm sensitive to overheat potential b/c motor had some melted wire insulation when I acquired it as a non-runner. Since there was zero pump activity at acquisition, I believed that new pump assembly had alleviated any overheat issue. Pump action seems pretty good, but that doesn't mean flow is good.
Questions:
Without unbolting head from midsection, is there a diagnostic for water tube UPPER grommet collapse --- such as fishing wire up copper tube?
How could I determine that the anchor point within the UPPER grommet has changed -- with the effect that tube has moved higher than designed? If that tends to happen, I could understand how tube lower end may not seat properly inside LOWER grommet on water pump -- with effect that water pump pressure could further push tube out of alignment and reduce flow to the block.Is there a way to assess the proper copper tube position without removing midsection?
I appreciate your help....thank you!

I do that with my '84 6hp but its water tube is more or less straight. What happens with that is that corrosion around the grommet squeezes the grommet over the end of the tube until it cuts off the water flow. A stout wire up the water tube should pass right through until it hits something solid but when the grommet is closed over the end I feel something rubbery at the top.

You have no doubt seen from the parts diagram that your water tube is far from straight. and a wire probably wont go round the bends.

I think your best bet is to unbolt the power-head from the exhaust housing and have a look at what is going on.

You may find that the water channels are blocked

Have you tried connecting a hose to the water tube to see if much water gets through. If it doesn't you are going to have to separate the power head from the leg anyway
 

Good Trout To You Sir

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F_R & Vic.S: Thanks for your feedback. Vic - I will try compressed air, then water through the copper tube tomorrow. I spent some time trying to find adapter/connector materials that will allow me to use a garden hose to connect to the copper water tube.
On your 6HP, how hot does the comparable area on midsection mount become when you are running at speed? Thanks.
 
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