Westerbeake 7.2 generator in 1999 38' Searay

Discussion in 'Electronics Q&A' started by DVILLANDRE, Sep 19, 2015.

  1. PlayDate

    PlayDate Well-Known Member SILVER Sponsor

    Dec 25, 2006
    Washington DC
    1994 370 Express Cruiser
    454 Mercruisers
    You said you replaced the overspeed board. Where did you get it?

    If you look at your schematic, you can see the water temp and exhaust temp are normally closed switches, the oil pressure switch is normally open when the engine is not cranking/running. The preheat switch bypasses the safetys electrical circuit but once released looks for a complete closed switch circuit with 12 volts. If 12 volts is not present, the coil and fuel pump are de-energized. With cranking/normal oil pressure ....all the safetys are in the closed position and 12 volts runs through them. So, when you test the temp and exhaust temp switches with an ohm meter with the engine off they should read closed so jumping them is unlikely to mean something unless they were stuck open. The oil pressure switch is more interesting because it is normally open on your generator. I believe you said you replaced it. Westerbeke makes two that look identical: one normally open and one normally closed.

    An ohmeter should read the oil pressure switch open with the engine off. If by some strange chance, you put a closed one in as a replacement....that would explain the entire problem.

    I will try to upload the schematic so that we can trace it together.

    -John
     
  2. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    I got the overspeed board from Hansen marine in Massachusetts.
     
  3. PlayDate

    PlayDate Well-Known Member SILVER Sponsor

    Dec 25, 2006
    Washington DC
    1994 370 Express Cruiser
    454 Mercruisers
    7.2 Schematic This should match your generator.
     

    Attached Files:

  4. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    After troubleshooting and spending over 60 hours trying to figure out what was wrong with my generator, replacing old parts with new parts etc. I almost threw in the towel. Today was going to be the last day before I called in a professional. I filled up the governor because the oil looked a little low-having put in new oil about 3 weeks ago. Guess when I put in the new oil I didn't put in enough. It started right up and ran for an hour. Unbelievable!
     
  5. PlayDate

    PlayDate Well-Known Member SILVER Sponsor

    Dec 25, 2006
    Washington DC
    1994 370 Express Cruiser
    454 Mercruisers
    Well you earned your Westerbeke merit badge on this one. Congrats on solving the problem. So, apparently it was the engine speed (overspeed) that was causing it to shut down when you released the pre-heat switch. Makes sense.

    John
     
  6. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    Wow!!! The one time I didn't chime in and say to check the oil in the Gov and that's what was wrong Im happy you found the problem
     
  7. Boater420

    Boater420 Well-Known Member

    Mar 11, 2015
    Clearwater, FL
    '97 330 Sundancer
    V-Drives
    Westerbeke 4.5BCG
    Twin Merc 454's
    Id did in post #18....too bad you missed it...would have saved a lot of those 60 hours and parts.
     
  8. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    There is one other thing to keep an eye on with our older units. Find and keep as a spare the gov spring. They get weak with age and use, when they get weak it will act just the same as low oil. Also if this makes you feel any better about the money and parts. When I bought my 88 my dealer spent 24 man hours, many new parts, rebuilt the carb, changed sensors, and had a certified Wester guy work on it for two days. I finally stopped my dealer due to the costs HE was paying out for a 9800.00 sale. ALL of that for 2 ounces of gov oil.
     
  9. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    I did see your post that's what was on my mind. I had noticed that the governor was low on oil what I started this project I cleaned out the oil and filled it up. I read that it only needs 3 ounces of oil so I filled it up. Apparently, I measured incorrectly.
     
  10. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    After adding the oil to my governor the generator ran for 3 hours the first day, it ran for about 1 hour the next day. I didn't go down to my boat for about a week. Friday, I went down started the generator and it ran and stopped with no load. What's funny about it is that load or no load the RPM's don't fluctuate. It always runs on high. Do you think the governor is shot? I tried to do an adjustment on hunting speed which it ran for a brief time then stalled again. I couldn't get it to run without holding the preheat switch on its own. Please advise.
     
  11. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    Start simple. Recheck the oil in both the gov and engine. When was the last tuneup? Including the fuel filter.

    The sping on the gov gets weak but don't keep throwing parts at the unit. It might be time to bring a certified mechanic and let them do the hunting
     
  12. Boater420

    Boater420 Well-Known Member

    Mar 11, 2015
    Clearwater, FL
    '97 330 Sundancer
    V-Drives
    Westerbeke 4.5BCG
    Twin Merc 454's
    If the governor was run while low on oil for any length of time the governor might need to be rebuilt or replaced. I went through the same exact scenario you are experiencing now. The generator ran fine for an hour or so and would just stop. After a complete service (plugs, impeller, oil, coolant, wires) there was nothing left to replace. I looked at the manual and noticed the governor also needed oil.

    I pulled the governor off the generator and noticed there was no oil in the governor. I then filled it with oil but noticed it was leaking around the shaft seal. I re-installed the leaking governor which was now now filled with oil to see if it fixed the problem, but the damage was already done. I had the governor rebuilt and the problem was solved.

    Something else to check...get a meter that measures Hz. When the governor is running you should see pretty close to 60hz on the meter. If your HZ measurement is more than 60, the overspeed board might be shutting the unit down. If the generator is running at more than 1800 rpm it is producing more than 60hz which will in turn burn up the devices using the electricity like your AC unit or microwave.

    When I got my governor back from the shop I installed it and then fired up the generator. It did the exact same thing and shut off. I set up my meter to measure Hz, fired up the generator and held in the pre-heat switch long enough to measure the HZ and it was at 62.3. I then adjusted the rpm setting and fired up the generator. It worked perfectly, and the Hz reading was now at 59.8. After some more adjusting I was able to get it pretty close to 60hz and all is well.

    If all else has been checked and is in proper range, chances are it's the governor causing you your troubles. Either the generator is running too fast and the unit is shutting itself off as it should (more than 60hz), or the governor is shot and needs to be rebuilt. You should keep a meter for measuring hz on the boat and check it monthly.
     
  13. ttmott

    ttmott Well-Known Member GOLD Sponsor

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    Sea Ray modified the power / run circuit in the generators; at least that is the way my BTD is. The boat's Halon fire system relay box is part of the run loop of the electrical wiring and power on for the generator energizes the relay in the relay box. There is no good documentation out there unless you have access to Sea Ray's engineering, which I did and made up a comprehensive end to end schematic. See schematic of mine below. When I was having start and run issues, after many hours of TS I found it was simply a loose screw on one of the terminal strips (TB1-1) in the generator's junction box. That loose screw was the ignition loop through a connector and that Halon relay box.
    [​IMG]
     
  14. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    Thanks for the info. How exactly do you check the Hz? Is it an outlet?
     
  15. Boater420

    Boater420 Well-Known Member

    Mar 11, 2015
    Clearwater, FL
    '97 330 Sundancer
    V-Drives
    Westerbeke 4.5BCG
    Twin Merc 454's
    You check HZ by plugging the the test probes into any 110v outlet on the boat. There is one by my cockpit refrigerator which allows me to see the reading from where I sit in the the engine compartment. If you don't have one there or a helper to read the meter get an extension cord and bring the meter right next to you so you can see it and hold down the pre-heat button at the same time.

    I got my multimeter at Home Depot for about $135. Fluke was the brand name. Once you purchase the meter, take it home and practice taking a reading from an outlet in your home. It should be a dead on 60hz.

    Then go to the boat and do the same thing with the genny running and the "outlets" breaker turned on. If you see more than 60hz adjust the RPM of the generator till it reads 60hhz.
     
  16. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    So, I checked the hz and it measured 89hz. I adjusted it to 60hz and the generator still only runs with the preheat switch held. The generator does not idle it seems like it is always racing, load or no load. Shouldn't it drop to a idle with no load?
     
  17. DVILLANDRE

    DVILLANDRE Member

    30
    Apr 26, 2015
    long island
    1999 38" sundancer
    454 gas
    So it turned out to be a corroded wire behind the fuse holder. Replaced the fuse holder and it runs like a charm. Figured I would post it if anyone else has the problem.
     

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