'88 9.9hp cooling water flowing, backwards?

[acbill]

I have a 1988 Johnson 9.9hp and recently did a head gasket and water pump replace. Now when running I get a very weak tell tale and it eventually overheats. Checked, impeller and key, no thermo, head gasket is good and tight to spec at 175 inch pounds, good compression, plenty of water out of the bottom but it's cold and there's not much water at the prop. The water out of the tell tale will scald your hand. My laser thermo gets temps over 230 at the bottom of the head after running at idle for 5 minutes. While open I cleaned and blew out everything including all water passage openings. The head was fairly clean with no major buildup. When I look at the water circulation diagram for a johnson 9.9 the water out of the tell tale looks like it should be cold and out of the prop it's hot. I don't get it? I took off the thermostat cover and ran the engine briefly to see if water would come out of the thermo housing and nothing, like no water is moving. Any body got any ideas?

 

[ondarvr]

There is a rubber grommet between the power head and midsection, they frequently swell up and restrict flow. Or you didn't get the water tube lined up correctly.

 

[acbill]

I didn't remove the water tube from the power head I only removed the lower unit. I made sure the water tube was seated in the water pump grommet before i connected the shift rod and tightened the lower unit. Water pump plate is positioned correctly, impeller is locked with key, impeller is new and impeller housing is good. Everything seems as it should be. The head gasket is positioned correctly and seated. I just can't figure why I get hot water from the tell tale and cold water at the prop, that seems backwards to me.

 

[flyingscott]

Did you change the waterpump for a reason.

 

[acbill]

Not really, just doing a good cleanup and cleanout before the season starts. This motor sat for a few years but ran with no probs before I changed out the water pump and head gasket. I would say I should tear it all down again and make sure everything is right but I already did that, twice. Any idea why hot water comes out of the tell tale and cold at the prop? Seems impossible it could be doing that.

 

[oldboat1]

could pull off the l.u. again(!) and try to manually flush the powerhead. Find a way of stepping down the hose to the water tube diameter, and turn it on maybe 1/3 or 1/2 open. Check flow exiting motor.

I would take a flashlight and look up under the leg by the powerhead as well. Look for mouse or mud dauber nests. If you pull off the t.stat cover, you can flush down as well. While your at it, I would dunk the l.u. in a tub and pump it manually (can use a hand drill, believe it or not) -- should get a strong flow if the impeller is doing its job.

If it's a salt water motor, it may be a matter of clearing out corrosion.

 

[acbill]

oldboat1, Good idea! I should have thought of that. I have used compressed air but not water. I will try what you suggested today and post the results. Thanks!

 

[Vic.S]

Take note of what Ondavr says about the grommet at the top of the water tube. They are a PITA. It may not be the problem but be aware that if could be.

part #55 in ( the one at the top of #54, the other one only applies to 15hp)

If you poke a wire up the water tube and it hits something squidgy that's the grommet and it's blocking the water flow

 

[acbill]

Thanks Capt. Vic, I can certainly appreciate Ondavr's suggestion about the water tube grommet. I passed a piece of welding rod up through the water tube from the LU end connection and hit metal which I assumed was a plate of some sort but it was not soft. I am going to try what oldboat1 suggested and use water to flush through every water passage and see what kind of flow I get. I used air but air is hard to see, water will be better of course. Just trying to think it through I am wondering if something is amiss in the water jacket on the side of the block allowing the cooling water from the water pump to flow the wrong way. Hot water at tell tale and cold water at prop. I can usually figure this stuff out but this is a doozy.

 

[racerone]

There is a blockage in this motor.-----Best to find it before you fry the motor.-----These motors do not shutdown when overheat is detected.-----They keep running till they come to a big $$$$ dynamic halt.

 

[acbill]

Hello again racerone, Yes sir I am babying it for sure until I find out what the problem is. You have helped me on other projects with different motors over the years which I appreciate. Glad to see we are both still kicking. I am going to pull the LU today and flush thru the water tube and also thru the thermostat cover per oldboat1's advice and see where the flow goes. This little elec. start 9.9 is a like new cream puff and has always run perfect so I won't do anything to fry it for sure. If I can't figure it out with help from the forum I'll take it to a dealer and spend the bucks rather than hurt it.

 

[racerone]

Using a shop may cast you $100/hr and you will not learn how simple some of this work is.

 

[ondarvr]

Frequently they won't work on a motor that old, the cost of repairs quickly exceeds the value of the motor.

A bad head gasket can cause the symptoms you describe, it over powers the water pump and prevents water from cooling the powerhead, this can create the situation where hot steaming water can come of the pee tube. You said the head gasket was good, but..

 

[acbill]

Hi ondarvr, I just pulled the lower unit and head. I tried to pump water thru a hose up thru the water tube and no flow anywhere. The hose connection was very tight and not leaking and I used about 50 lbs of water pressure. I tried to take off the water jacket but one of the screws is not accessible without pulling the power head. The head gasket is new and is the oem part., water pump is new. Seems to be a blockage, per racerone, but I'm not sure where it is or how to clear it. The water ports in the head are clear. Is there supposed to be a diverter in this head? All accessible water ports seem to be open but allowing water to flow in the right direction is another story.

 

[ondarvr]

You may need to pull the powerhead off, it's not hard to do.

 

[acbill]

Something else. Using the hose i pushed water up the water tube at about 50 psi but there was very little water that came out of the water port that cools the head. I don't know if that test should have produced full unresrticted flow or a diminished flow. When doing that test with the hose I did notice that a good stream of water did come out of the pee hole. This is with the head off flushing thru the water tube. It seems that some but not enough water is getting forced thru the head from the water pump.

 

[acbill]

I've never pulled a power head and I'm a little uncertain how to tackle that.

 

[racerone]

Sorry, but you need to accept that it is just nuts and bolts to take the power head off.----Go for it.

 

[oldboat1]

Hi acbill. Sorry to see flushing didn't get it. It's likely you will need to pull the powerhead, as indicated. Before doing that, though, you might pull off the head cover, and see if you can explore passages for a blockage -- some probing, and a little more flushing -- might hit it.

I'm up to my elbows in bottom paint, and think I would rather be pulling a powerhead. Not too bad on the 9.9.

 

[racerone]

The 1988 model may have a thermostat cover , but no water passage cover like earlier models had.