Westerbeke need a siphon break??

Discussion in 'Sport Cruisers' started by Jimmy Buoy, Jun 14, 2009.

  1. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Hi all!

    I've been reading one too many stories of gennys dying from water injestion as a result of not having a siphon break. So I've taken a look at my Westerbeke 4.5 BCGB - no siphon break at the top of the cooling hose loop.:huh:

    I've haven't had a problem and the unit appears to be original, but every time I go to fire it up I'm concerned.:smt009

    Will it crank one time too many and gulp water like others??:wow:

    Is it safe/accurate to say "if it needed a siphon break, Sea Ray would've installed one"?:huh:

    It seems like a cheap and easy part to install. What do you think gang?:grin:
     
  2. midexp

    midexp Active Member

    108
    Oct 5, 2016
    Harrison Township, Michigan Lake St.Clair
    1999 40' Sundancer
    454 merc
    Can someone please comment as to if they have one of these siphon breaks on their generator? I don't and am getting water in my oil. Local Sea Ray dealer says every boat he's look at has one, but I know of 2 41 dancers that do not have one. Curious as to what others have.
    Thanks
     
  3. sr330daguy

    sr330daguy Member

    446
    Mar 14, 2007
    Hudson River
    97 330da
    7.4 MPI's Bravo 1s
    Westebeke 4.5
    My 97 330 does
     
  4. cfd95

    cfd95 Member

    287
    Nov 5, 2013
    Northport Long Island
    2002 310 Sundancer
    350 Horizons
    V Drives
    my 2002 310 has one
     
  5. juggernaut1

    juggernaut1 Active Member

    772
    Apr 19, 2015
    Perth, Western Australia
    2006 38 Sundancer
    8.1S / ZF 63V Drives
    My 2006 38 has one too.
     
  6. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    My 88 and my neighbors 87 does not
     
  7. ttmott

    ttmott Well-Known Member

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    A siphon break will not fix over-cranking and filling the exhaust system and consequently the engine with water. The siphon break will, however, prevent water from siphoning into the exhaust system when the generator's exhaust raw water inlet is near or below the water level.
     
  8. northern

    northern Well-Known Member

    Jan 17, 2007
    West coast Vancouver to Alaska
    380 Aft Cabin 1989 GPS and Charts by Nobeltec
    Twin 454 strait shaft
    We have one and it leaks a little water into the bilge. Generator is 8KW Quicksilver.
    Can someone explain how over cranking can get water into the engine. That is how I put propylene glycol (Pink) into my main engines in the fall. I put in 4 gallons. I pour it into the strainer and crank the engine with the wire off between the coil and the distributor.
     
  9. ttmott

    ttmott Well-Known Member

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    The raw water pump turns during cranking and delivers water to the exhaust riser; the water flows to the lift muffler and eventually backs up and fills the exhaust riser and then flows into the engine's exhaust ports. As the engine is not running there is no exhaust flow and pressure to drive the water from the lift muffler.
     
  10. PlayDate

    PlayDate Well-Known Member SILVER Sponsor

    Dec 25, 2006
    Washington DC
    1994 370 Express Cruiser
    454 Mercruisers
    If memory serves me correctly I believe Sea Ray installed siphon breaks beginning in 1995 or 1996 on all boats with generators. The generator manufacturer's required them.
     
  11. hottoddie

    hottoddie Well-Known Member

    Jan 11, 2012
    Boston/Cape Cod
    1986 Sea Ray 390 Express
    Garmin 4212 Chartplotter
    Garmin 24 HD Radar
    Garmin GSD 22 Sounder
    Garm
    454 Crusaders
    My 1986 390EC has one for the Westerbeke 8kw. It was on the boat 8 years ago when I bought it. Strongly recommended
     
  12. Boat Guy

    Boat Guy Well-Known Member

    Pictures of what you're talking about?
     
  13. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Hey guys, this post was started over 9yrs ago. Maybe time for an update??

    I never did add a siphon break to the system and have used the generator each season without any issues.
     
  14. midexp

    midexp Active Member

    108
    Oct 5, 2016
    Harrison Township, Michigan Lake St.Clair
    1999 40' Sundancer
    454 merc
    I was not the one who originally started this thread a while back, but I resurrected it. I was Googling to help find a reason for water in my oil on my Westerbeke generator and ran across the topic on CSR. And like many threads, the final fix was not mentioned. But it sounds like the water in my genny is getting there because I don’t have one of these “siphon breaks”. Basically, it’s a loop in the raw water hose that runs from the heat exchanger to the exhaust elbow. On my genny, this hose enters the exhaust elbow with the fitting in the elbow facing straight down. So there’s no loop.
    In my owner’s manual, Westerbeke shows the hose running just as mine is. But the following year, their owner’s manual shows the hose entering from the top following a loop in the hose with the fitting in the elbow pointing straight up. And they make a point that this loop is recommended. Pretty piss poor communication.
    So from the responses on this site, most if not all have the hose loop in that creates this siphon break. Now what I don’t understand is what type of siphon break. There’s three I found. One is simply looping the hose upwards into the elbow fitting pointing straight up. Then there’s a separate 180° loop that connects the water hose to the elbow (attached in pic). Then there’s a siphon valve that somehow fits into the water hose. Not sure what everyone else has? The Westerbeke part numbers are 049954 and 33327, so Google and see.
    Not sure what kind of damage I’ve done to my genny? I just got the boat and the genny’s got 277 hours. Starts fine and runs fine. Not sure when this problem started. Do I need to just make the water hose a loop, or make the loop and buy a valve?
     

    Attached Files:

  15. ttmott

    ttmott Well-Known Member

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    Maybe, maybe not - if your generators exhaust water inlet is below 12 inches above the water line you need a loop at least 12 inches above the water line and siphon (vacuum) break valve at the loop high point. Regardless, It's good practice to have a loop and vacuum breaker well up into the boat's gunnel.
     
  16. techmitch

    techmitch Well-Known Member SILVER Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    Tom, always appreciate your very informative post, especially the electrical/electronics stuff. But this one I'm having a hard time wrapping my head around. Thanks, Mitch
     
  17. techmitch

    techmitch Well-Known Member SILVER Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    I guess it's "raw water inlet near or below the water level/line" that is throwing me a curve as I would think it should always be below?
     
  18. ttmott

    ttmott Well-Known Member

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    Understand, probably needed to be a bit more descriptive - It's important to understand where the raw water inlet for the generator's exhaust is relative to the water level on the boat. If that water connection on the generator's exhaust is below the water line then a loop and anti-siphon valve is required. However, the loop and valve are good practice for all installations. There appear to be some examples of factory installations that are marginal (SR did do several bulletins over the years). Most water intrusion cases are simply from over cranking the engine. Maybe this pic better explains -
    siphon.jpg
     
    Last edited: Jul 11, 2018
  19. CliffA

    CliffA Well-Known Member GOLD Sponsor

    Dec 29, 2009
    Lake Norman, NC
    2001 Sea Ray 340DA
    Name: 'Happy Place'
    4.5kW West. Generator
    Purchased Nov. 2014
    Fresh Water Use
    Twin Merc. 6.2L (MPI)
    Raw Water Cooled
    V-Drive Transmissions
    if it helps you can sort of see the siphon break in this pic of my genny and starboard engine.....I have not really studied how it works so really can't answer questions about it....

    cliff

    starboard engine and generator.jpg
     
  20. Boat Guy

    Boat Guy Well-Known Member

    I'll try and take a look at mine today.... Does anyone else with a 400DA know if they have one?
     

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