[C320-list] Raw water system

[Jeff Hare]

Hey,  (translated "hi" elsewhere)

I have experienced this problem from time to time even with a brand new impeller. 

I suspect two things:
1. My pump body is worn and the impeller doesn't make a tight seal even with a new impeller. 
2.  My raw water intake hose leading to the pump loops up too high for my current pump. 

I plan to replace the pump this spring and lower the hump in the hose a little.

I have checked that the through hull, strainer, pump and exchanger are all clear.  Also, I observed that by dabbing impeller grease in the pump housing it draws water without priming.  So, my conclusion is that the scoring on the outer plate of the pump is preventing a good vaccuum from forming. 

Sooo.  Loosen the pump inlet hose and get air out of the line and water into pump.  If it pumps water now, you *may* have one or both of the above problems. 

-Jeff 
------Original Message------
From: james_delong
Sender: c320-list-bounces at lists.catalina320.com
To: c320-list at lists.catalina320.com
ReplyTo: C320-List at Catalina320.com
Subject: [C320-list] Raw water system
Sent: Jan 11, 2010 9:35 AM

Y'all, (I'm allowed to use that term as I'm in Georgia)

Anyway...

I have an issue with the raw water system.  It seems to work intermently!  

Yep...checked the sea cock (clear), strainer (clear) and impeller (new)....

What is next?  I'm assuming the raw rater pump itself (do these fail?), heat exchanger and the mixing elbow, but don't want to tackle those without some indication either of these could be the culprit!

Some history.  Once we smelled rubber burning like the pump stopped rotation.  After checking this and tightening the belt all was OK.  A couple of other times there was no exhaust water, but the next time there was!  After the last sail, all was OK.  But starting the boat at the dock now results in no flow at all.

Ideas?

Thanks,

Jim #453