70 Hp water drains slow

[wrmdunker]

It’s a 1974 70 Hp Evinrude. I installed an OMC water pump kit. First time for me on this motor but I’ve done my 10 Hp before. This model does not have a pee stream but Ive been meaning to add one.

So I did the pump. Had help guiding the LU back on. Everything went well. Ran it in a barrel and ran fine. The block never got hot but I didn’t think that was a problem without being under a load.

My issue is the water keeps draining…..and draining....and draining after I shut down and removed the barrel. After about 30 minutes I caught about ANOTHER 16 oz. Dumped that. Caught another 8. Had dinner. Came back a still draining. Another 16 oz. Never had this issue before. Typicalyl I pull it from the lake and water runs out fine. Seems there is some blockage somewhere and it is in a vaccum.

I rotate the flywheel (CW) and that frees up more water to a constant stream and then goes back to a steady drip. Water is coming out the starboard side housing drain just below the upper gear oil screw. Ran a wire in the 2 starboard holes and the front center. Tried a little air also.

So what do I do? Take it to the lake and run it hard? Pull the Lower Unit and check the pump vanes? I don’t think there is any way I missed getting the pump outlet lined up with the tube. I soaped it make for an easy fit…….

I'm stumped.

 

[wrmdunker]

I must add that the pump makes an odd sound when I turn the flywheel but I think that is just the new rubber. Old one was 6 YO.

Also could I have overtightened the pump housing. Guess about 5 foot pounds but I did not measure. The housings have brass inserts to keep from causing compression damage........

 

[TrueNorthist]

The "groaning" is the fresh, new legs doing their thing, so no worries there. I hear that every time and it is a comfort really. Means the key and shaft are located well. But the drip, drip, drip might indicate sand or crud in the cooling system. Did you do the thermostat too? At best it will only ad an extra 10 bucks or so for a gasket, or you might be able to save the old one. Once the thermo is out you can even run water through the head jacket and watch what happens. I find compressed air backwards through the pee tube helps, but that is a non-starter here unfortunately. Best get around to that job matey!

BTW, if others want to jump in please do. I don't mind one bit.

 

[wrmdunker]

I did not do the stat but the shop did 6 years ago.. Good to know about the vanes squeeking. I have not had it out for a year since my last trip to Vermont. but I never run it aground or too shallow. I like running in a barrel for tuning but may try the muffs for a LITTLE water pressure. Maybe the new impeller dislodged some scale.......?????

Went back to garage and dumped another 20 ounces. Measured it! Does the volume of water bother anyone? Like 1/2 gallon.

 

[emdsapmgr]

The lower part of the midsection and the top of the lower unit have drain holes to let the water out of the midsection. They may be plugged with silt/sand, causing your slow draining. (The water is held in the midsection to reduce exhaust noise.) Constantly drains and is repl by new water from the block. Clogged drain holes are probably not unusual on an older engine. For peach of mind, you may want try to clean them out with a small wire or rod. If you are not successful, you may need to drop the lower and clean out those drain holes. The impeller housing will hold a small amount of water once the engine is shut off. If you rotate the flywheel by hand, you will see a small amount of extra water flow out of the lower. That's normal. Most folks don't rotate the flywheel after winterizing the engine, as the retained water in the pump is not enough to cause freezing problems in the winter-but I always turn mine 1 turn by hand each fall to assure that absolutely all the water is out of the engine.

 

[wrmdunker]

emd,,,,,So what do you think about removing the stat and lower unit and rigging a flush hose up to the pump tube? I dont like the idea of possibly moving the tube out of the upper grommet and not getting it back it. Makes sense about the pump vanes holding water but I think I did a full rotation of the flywheel. However, I'm still draining back down the tube and refilling the vanes........The wire I did use was about 14 ga. Maybe I need to go smaller. Also probed the hole near the top of the midsection housing gasket.

 

[emdsapmgr]

Not sure just what you are trying to accomplish by flushing up the water pickup tube in the midsection. That procedure could be used if you wanted to flush the powerhead. I thought your problem was that the engine retained water inside the midsection for a long time. That it was slow to drain. To me that indicates that the drain holes at the top of the lower unit may be plugged/restricted-retaining water inside the midsection. Maybe you can clarify just where you thing the water is accumulating.

 

[wrmdunker]

Well emd......I'm not sure where the water is accumulating. Yes, I did think that the flushing would get at the powerhead cooling chambers. Perhaps thats overkill. When it was initially draining I did hear a "gurgling" sound but it was difficult to determine where that noise was coming from. As I said, I tried to probe and air clean the orifice at the base of the front exhaust housing cover. Wouldnt that be the vacuum relief for the midsection?

When I have used the muffs, I have gotten water squirting out that hole at the top of the midsection so perhaps that is what I need to do. Did not get a chance to work on it today. Lots of yard work here in Ohio. I will try that Thursday......

 

[wrmdunker]

I have had 63 views at this point. If anyone had the opinion that I did something wrong with the impeller/housing change I hope they would have said. So I guess this slow drainage is just coincidental.........

 

[wrmdunker]

Well I ran it on the muffs with a low flow. Water exiting all the drain holes and then drained normally. 2 ounces. Guess whatever blockage I had was flushed with the muffs. Might seem paranoid but leaving for 2 weeks of fishing and didnt need problems.

Thanks all.