water pump will not pump in choppy seas

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R

Russ

I have a 89 30 Catalina. I just replace the impeller on the pump. It pumps great at the dock and good when motoring in calm seas. But, when seas are a little choppy it will not pump. I do not have a scoop on the water intake, do you think this would make a difference? Thanks, Russ
 
Jan 15, 2006
21
- - Dallas
why do you say it doesn't pump

Why do you say it doesn't pump water? Are you looking at the exahust, or did you take the hose off the pump and watch the water coming out of the pump? I'm not trying to be smart, just trying to understand the problem. If no (or little) water is coming out of the pump and you changed the impeller, you might want to change the little "flipper" (my word) that is inside the pump. If you look closley, you will see the inside of the pump is not completely round. There is a little piece that is held in by a screw that is used to "flip" the impeller blades as the impler goes around and causing more suction. http://www.torresen.com/intersail/article.php?n=44&owner=sailbase If you are saying little water comes out the exahust, then maybe because the boat is pitching, the water isn't being pushed out the exahust as often, but when it does, there is more of it. Just my thoughts. Dave
 
R

Russ

water pump

There is no water coming out of the exhaust and the temp shoots up to over 200degrees.
 
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Russ

water pump

Dave, I failed to mentioned I have M25XP with a oberdoffer pump.
 
Jan 15, 2006
21
- - Dallas
The same applies

Both water pumps have the "flipper", and also for the M25XP. Could it be that when you changed the impeller, you might have pulley the shaft out too far and disengaged the pin from inside the engine? Not really a problem, but if you did maybe the impeller isn't turning as fast as it should. There's a write up somewhere about how to fix this, but I don't remember where it is. But, the more I think about what you are saying, maybe this isn't the problem, in which case I don't have a clue what could be causing loss of water flow. Dave
 
R

Russ

water pump

It seems like if I had a scoop on the raw water intake water would be forced to come to the pump. The Universal manual has a picture of a seacock with a scoop on the bottom. Russ
 
Jan 15, 2006
21
- - Dallas
Maybe

I don't have a scoop and I don't have a problem. The "flipper" is what causes the fingers of the impeller to creat a partial vacumn to pull the water from the strainer to the engine. Maybe you have a clogged strainer, or something in the hose from the strainer to the seacock? A little off topic, but similar in some respects, remember the old ping pong ball in the gas tank prank. The ping pong balls would float until the gas got low in the tank, then the suction from the fule pump would pull the ping pong balls to the fuel tank outlet. I'm just rambling now. Dave
 
Jan 15, 2006
21
- - Dallas
Here's the link

Here's the link to what I was talking about if you shaft comes out when you pull the impeller off.
 
Jan 15, 2006
21
- - Dallas
Here's the link to the "flipper"

It's really a cam. Item #7. They do wear out and therefore the amount of water going into the pump gets deminished. Dave
 
Jan 15, 2006
21
- - Dallas
Let's try that link for the cam again

http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&catalog=200142&model=M-25%20/%20M-25XP%20/%20M-25XPA&page_ident=200142-57&manufacturer=Universal&title=Orberdorfer%20Water%20Pump&size=800
 
R

Russell Traina

water pump

Dave, Thanks for all the info. I didn't tell you that I replaced the impeller a year ago and this problem has been going on off and on. It only happens when the boat is heeling or bouncing around. As for the exhaust, as soon as I notice the temp is up I always look at the exhaust flapper. No water pumping. I then turn it off and don"t use the motor until I get in smooth water and it pumps like a champ. I saw the part you were talking and I will order it. Thanks, Russ
 
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