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72 50hp Evinrude Not Pumping water

bill_w

bill_w

Advanced Contributor
This motor has given me fits all summer. It sat for about 2 years, then I fired it up this spring. Started right up, but no water flow from the exhaust ports. I have followed all of the suggestions on here, and if I tear this motor down one more time, I may throw it in the scrap bin. Summary of things done so far.

replace impeller, check intake ports
replace thermostat and pressure relief valve and grommet
remove powerhead, check for obstructions in the block, and the water pump tube
replace lower water tube grommet, change original grommet at top of tube to new style washers
run on muffs...with muffs held tight to intake ports, trickle of water out of exhaust
run in tank....no water from exhaust
run in tank, with head cover, thermostat and pressure relief valve removed...no water from thermostat hole...get exhaust out of hole

and yes, the impeller is installed the right way, and the drive key is engaged into the shaft and impeller. I have gone over the housing about 5 times....no cracks, splits. The lower exhasut tube gasket is in good shape.

So...What next?? Turn it into beer cans???

Bill
 
Did you 'run' (use a power drill and splined socket) the lower gearcase with powerhead removed checking that water was coming up to the block?
 
Hi Haffiman. That is one thing I haven't done yet. I have to make up an extension to fit the socket and my 1/2" drill. That is on my list of things to do, along with trying to get my 115's running.
 
Easier way...take an old 1/2" extension, cut the end off, turn it down in a lathe. Did that today. Also talked to my marine mechanic today. He said it's probably something stupid and small.
 
Tried out the new tool yesterday. The pump works, it's shooting water about 2 - 3 feet straight up, past the exhaust adapter. I did find the gasket on the exhaust tube (not the rubber seal) is shot. I'm wondering if the exhaust could have been getting to the pump (thats the side its gone on) and disrupting the intake of water? And, while I have the powerhead off (again!!!) I'm going to try blowing compressed air through the block with the head cover off, and the pressure relief and thermostat removed. I think it's taking way too much pressure to get water to go through the block, just by trying it with a garden hose. Maybe something nested in there during the motors 2 years off???

I'll try that, and reassemble it again with a new exhaust tube gasket. Just maybe I can get it fixed before its time to put it away for another winter.

Bill
 
Haffiman...no blockage on the way out..that was one of the first things checked the first time the powerhead came off.
Capnlazy...I'm starting to think so too. I did have it running with the thermostat out, and I did get exhaust out of the thermostat hole.

I did blow air and water through the block today. It seems clear. So, back to my friendly parts lady at the OMC dealer. I think she has my phone number on speed dial. I checked the bottom of the exhaust tube today..it's not a gasket as I thought, but a rubber seal that has been compressed enough to look like a gasket.
 
'and I did get exhaust out of the thermostat hole. '

From where?
The only place exhaust may enter into the cooling system and out the thermostat, unless a totally defect head gasket', is the exhaust cover/gasket or through the water tube.
 
I don't believe the grommet where the water tube enters the water pump totally seals around the water tube. I believe exhaust pressure can displace the water in the water tube at this point. It could also be the gasket under the powerhead.
 
I'm thinking the water tube guys...through the relief hole or cooling hole (whatever) about 1/2 way up the tube. The water tube grommet at the pump end seems to do a total seal, as do the washers at the exhaust adapter.

With the bottom seal gone on the exhaust tube, exhaust can get into the water pump side, into the hole in the tube, and into whatever other openings there are for water on that side, and out the thermostat opening. The gaskets on both sides of the exhaust adapter have been replaced a couple of times now, with me pulling the $%#@&** powerhead off and on. And, this problem started before I started ripping things apart. New grommets / washers on both ends of the water tube. And Haffiman, when I pulled the water tube off the exhaust adapter, it was a washer there, not a grommet. Washer was in bad shape though, flattened and hard.

I'm hoping / praying that the rubber exhaust tube seal will cure the problem. I'll let you know in a couple of weeks.

Bill
 
Will be again when I put it back together again. Only one original from factory, I had 2 of the new style/number in it after the first tear down, and during it's latest testing. I think I can take it apart in my sleep now.
 
Just to summarize:
Spinning the gear case with a power drill, water shoots up 3 feet from pump? If so, pump works.
If attaching water hose to water tube - water flows freely through block and to thermostat. With thermostat and pressure valve installed, water/air leaking through bleed hole in thermostat.
Water exits through water channel only and not the inner exhaust tube??
Correct gaskets used that matches water and exhaust channels and seals where supposed to seal???
Gaskets #67 and #69 sealing??
http://www.marineengine.com/parts/j...ohnson&section=Exhaust+Housing+Electric+Start
 
Haffiman
Right now, its still in pieces, waiting for more gaskets. Water shoots out of water tube 2-3 feet above top of tube, when spinning with drill. Rest of it is unknown right now. Before pulling apart, tried on muffs again...very little water out of exhaust ports when muffs held on tight. In tank, no water out of exhaust.

So far, through all the tear downs and reassembles, the correct gaskets have been used. Remember, this engine had never been apart until this year. So all factory gaskets were still in it when I changed the impeller.

When I had it running in the tank, with the head cover off, thermostat and relief valve removed, only exhaust from the thermostat hole,

It worked fine before being parked for a couple of years. Once I change the exhaust tube gasket, and reassemble, I'll post the results. I really think its got something to do with the exhaust tube lower seal.

Bill
 
It lives!!! After spending the summer on this project, it seems the lower exhaust tube gasket/seal was the problem. I changed this one out yesterday, reassembled the beast for the nth time, and now it's not overheating. Still not a lot of water from the exhaust outlets, but not overheating when running in the tank. For the record, the seal part number is 315955, part no 67 on the parts diagram. Thanks for everyones help, maybe it will run for another 38 years.

Now onto the 115's. Out of three I have, I should be able to get one good one:)

Bill
 
One more thing...I seem to have a lot of water coming out of the midsection in the area of the starboard lower mount. Is this normal?
 
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