Generator salt water intake problem.

Ballyhoo1

Ensign
Joined
Jul 2, 2013
Posts
11
Likes
26
Location
Miami Beach Florida
Website
www.bluefincharters.net
Boat Make
Jarvis Newman
Hello all. My generator loses prime when I start it after it sits for a day or two. I have had this problem for 6 years and have tried increasing intake size, larger strainer, removing any 90* elbows, increase intake hose size. In addition, when I go out in rough seas, when I'm rocking and rolling, it loses prime then too. I have replaced my salt water pump as it has run dry because of this. The thru hull fitting ( direct intake-no scoop) is at or a little below the level of the generator and exhaust water muffler. The boat is a 46 Jarvis Newman and generator is a 3 cylinder 8 KW Westerbeke 8 TDB. Any thoughts or suggestions are greatly appreciated.
 

md2020

Ensign
Joined
Apr 22, 2013
Posts
9
Likes
4
Had some of the same issues with WB 5.0. The boat shop had installed strainer too high up, once I dropped strainer problem was gone. Water should travel up hill to genset, no high spots.
 

gregs

Lieutenant
Joined
Jan 28, 2012
Posts
96
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26
Location
Annapolis, MD
Boat Make
Flowers 38
I had an 8kw WB. My impellars lasted at best 250hrs. Once they broke they let air in and it would lose prime. If the pump is higher than the water level the potential to lose prime is much greater. When they do lose prime air has entered the system some where between the pump and the intake.
 

captjohn

Captain
Joined
Apr 12, 2013
Posts
786
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Age
63
Location
Seaford, NY
Boat Make
Henriques
Do you have an inline strainer (which you should)? I had a problem with the seals on my strainer, which allowed the generator to loose prime. When I replaced all the seals (make sure the bottom part of the strainer isn't distorted, it should be replaced if it is) the problem went away. Do not replace the inlet with a scoop style, you'll end up filling the muffler with water when your under way and the generator isn't running, resulting in water backing up into the engine.
 

delucat2

Lieutenant
Joined
Aug 10, 2013
Posts
69
Likes
8
My problem was an air leak in the strainer. To find it I pulled the hose off the through hull, applied compressed air and sprayed everything with soapy water. The wing bolt that went throught the center of the 1/2 inch poly cap was the culprit. New sealing washers solved it.
 
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