25 Evinrude Water Pump Issue

keithab

Recruit
Joined
Apr 22, 2010
Messages
4
Hello all,
Last week I volunteered to change a water pump in a friends 25 Evinrude. I pulled the lower unit and the old pump housing was totally melted, so I changed the housing, wear plate, impeller and associated gaskets. Before I re-installed the lower unit, I blew air up through the pickup hole in the bottom of the block to ensure the water passages were clear. Re-installed the lower unit, put it in the barrel and fired it up. Here's the problem, water will not come out of the tell tale, at idle, it barely spits out of the two exhaust ports on the midsection, rev it up, and the water increases out of the two ports, but still not out of the tell tale. With the motor in the barrel, I blew air through the tell tale and I get bubbles down at the water pickup on the lower unit, but still won't pump. Any ideas? Thanks in advance
 

bankerjohn

Chief Petty Officer
Joined
Mar 21, 2008
Messages
444
Re: 25 Evinrude Water Pump Issue

My guess would be you failed to get the "key" that locks the impeller to the drive shaft installed correctly.
 

keithab

Recruit
Joined
Apr 22, 2010
Messages
4
Re: 25 Evinrude Water Pump Issue

I have pulled it back apart and the key is still in place, like I said, if you increase the RPM's, the flow of water increases out of the exhaust ports, just does not come to the top of the motor where the tell tale comes out of. The key is in. It really has me baffeled. Is there a baseplate gasket on the block that could be letting water seep back down the exhaust and not circulate through the block?
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: 25 Evinrude Water Pump Issue

What year is the 25? Did it have a copper water tube in it?
 

wilde1j

Vice Admiral
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Apr 15, 2002
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5,964
Re: 25 Evinrude Water Pump Issue

You may not have the water deep enough in the barrel or whatever you're using.
 

bankerjohn

Chief Petty Officer
Joined
Mar 21, 2008
Messages
444
Re: 25 Evinrude Water Pump Issue

You need to post the model # of your motor, as not all motors have exactly the same set up!

Regarding wilde1j's comment, are you running the motor on muffs, or submerged in a barrel? If you're using a barrel, how deep?

Have you checked the grommets on the water tube? If a grommet gets "squished" due to improper re-insertion of the copper tube, that can prevent water from flowing up into the block.
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: 25 Evinrude Water Pump Issue

If things got hot enough to melt the water pump, melted rubber, melted grommets, and water deflectors. Pieces could also get into the thermostat.

From experience, I melted one before.
 

keithab

Recruit
Joined
Apr 22, 2010
Messages
4
Re: 25 Evinrude Water Pump Issue

I don't know the year of the motor, the friend brought the parts with him, so it didn't matter at the time, I will look tonight and post that tommorrow. I'd say it's mid 90's model and yes it has a brass pickup tube. The water level in the barrell is plenty high enough, it is above the cavitation plate, probably about two inches below the exhaust ports on the tower. On the top of the water pickup tube, there is only a washer, sort of nylon, there is no grommet on the top that I saw. This motor got hot, because the water pump housing was totally melted, worse than I've ever seen, but the funny part is the paint on the block is not discolored
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: 25 Evinrude Water Pump Issue

There should be a grommet on the top of the tube. Look up into the eshaust port, you may have to dig it out.
 

keithab

Recruit
Joined
Apr 22, 2010
Messages
4
Re: 25 Evinrude Water Pump Issue

I'll dig for the grommet tonight. I though of something else that may be worth mentioning. With the motor running, if you put your finger to the tell tale, there is hot air pressure coming out of it. Maybe this is normal and I don't know it because water normally would be mixed with it, but should there be air pressure coming out of it? Seems to me if exhaust pressure was getting somewhere it shouldn't be, then water would be going somewhere it shouldn't be also.
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: 25 Evinrude Water Pump Issue

If the water tube was not put into the round hole in the exhaust port, it would pump water up into the exhaust chamber. Then only air pressure would come out of the tell tale. Make sense?
 
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