Westerbeke 4.5 BCG Shutting Down After 1 Hour

Boater420

Boater420

Well-Known Member
Mar 11, 2015
1,259
Clearwater, FL
Boat Info
'97 330 Sundancer
V-Drives
Westerbeke 4.5BCG
Engines
Twin Merc 454's
Hello,

I have a Westerbeke 4.5 BCG in my 1997 330 DA which was running perfectly all day and night prior to this issue. My generator is shutting down after running for a while. Sometimes an hour, sometimes two hours. Here's what's happening...The generator fires up perfectly. Once warmed up I can apply a load with no problem (AC, hot water, outlets, microwave) and it continues to run perfectly. Right before it stops running, I hear the engine RPMs increase and then it dies like it was shut off at the switch.

Two things I've noticed:
1. As it's dying, I can press the "Stop" switch and it will continue to run for a few seconds and then the same thing happens again...Increased RPM's and then dies.
2. I can press the "Stop" button as it dies and it will continue to run for a few more seconds, however if I also press the preheat button it will stay running for as long as I hold the switch...let go of the Preheat and the engine RPMs increase and then it cuts out.

Generator Condition:
New oil & Westerbeke filter
Coolant just changed
New Spark Plugs
New Impeller and rebuild on sea water pump

I've tested the internal temps with an IR Thermometer and they are all within operating specs. Nothing hot to the touch, so I don't think it's overheating. It stays running for hours so I don't think it's oil pressure. I'm leaning towards the Overspeed Shutdown Board as the culprit. I've heard it can be bypassed by taking the T3 terminal and moving it to T5 terminal? When is this done, before or after the unit dies the first time?

Any advice or ideas appreciated.
 
It sounds to me like the overspeed shutdown board is your hero, not your culprit. Since you hear RPM's rise, then isn't it doing it's job with a shutdown? An overspeed generator can do very bad things to expensive stuff!

Has the governor been serviced lately?
 
The linkage is clean and lubed. I'm not sure about the oil as the boat is new to me within the last few months. I was under the impression that the board itself is faulty and causing the generator engine to rev? I was curious about how to test the Board using the test described...any experience?
 
If it will stay running when u hold the button down your bypassing all the safety switches. Ive had the same issue with mine (4.5bcga) minus the revving up. My findings were as followed. The shutdown was due to lack of seawater pressure. (I had just changed my impeller) so I pulled the seastrainer cap. Noticed the wood gasket was gone. Since I had as some pressure it would sometimes run but when it sucked air it would shut down. Replaced the gasket and the problem went away. It did take me a while to burp all the air out of the system. Had to sit next to the switches to bypass the shutdown. But after a couple minUtes the was out. I think its because the heat exchanger is so low in the system. But you could be just sucking air some were before getting into the main motherboard of the unit check the seawater sensor abd bypass it. Good luck
 
I don't have a seawater sensor that I'm aware of? I have:
High Exhaust Temperature
High Water Temperature Shutdown
Low Oil Pressure Shutdown Switch
High RPM Shutdown Switch

These switches might be faulty as well but I'm confused as to why it revs right before it dies?

I'm going to check the oil in the Governor as that is something that hasn't been checked already. I still would like to test the Over speed Board if anyone has tested that before please let me know how it's done.

I will bypass the other sensors tonight when I check the oil in the Gov.
 
Electricaldoctor,

If I understand correctly I am to bypass all the senssors, then start the generator. If it runs for several hours start without dying, start removing the jumpers until it dies?

Or

Run the generator until it dies, then bypass the sensors and start the generator. Remove the jumpers one at a time until the engine dies?

How do I bypass the Overspeed board?
 
Someone else mentioned the governor - check it. It contains oil, and if it runs low it will eat itself. I wasn't aware of that, and now I need to have it rebuilt (VERY expensive part to replace).
 
If I remember correctly it only takes 3oz of oil(please confirm) Dont over fill! I'm not sure if there really is a sensor for seawater pressure but once I replaced the gasket it never happened again. Possible coincidence but just seems like there has to be
 
The Westerbekes have 3 sensors that will shut down besides the overspeed board. Exhaust temp, oil pressure, and coolant temperature. If i remember correctly, when you press the on, it actually bypass the previously stated sensors. Until oil pressure builds and completes the oil pressure switch to close. If you look at the wiring for the engine you can confirm NC(normally Closed) vs NO (normally open) sensors. There is a built in check circuit on the overspeed by simply moving T5 to T3 i believe. I'd have to look it up to confirm, but basically it turns the overspeed off when in that mode. You can use a RPM meter to monitor the speed of the genny, to see if it's going above 3600 RPMs. I think it needs to hit much higher for it to shutdown for overspeed... Hope this helps... I got really good troubleshooting. The early board did have some issues. There are a couple of different replacement boards, you want a later one if you think it needs to be replaced.. Regards, Don
 
dcpringle said:
The Westerbekes have 3 sensors that will shut down besides the overspeed board. Exhaust temp, oil pressure, and coolant temperature. If i remember correctly, when you press the on, it actually bypass the previously stated sensors. Until oil pressure builds and completes the oil pressure switch to close. If you look at the wiring for the engine you can confirm NC(normally Closed) vs NO (normally open) sensors. There is a built in check circuit on the overspeed by simply moving T5 to T3 i believe. I'd have to look it up to confirm, but basically it turns the overspeed off when in that mode. You can use a RPM meter to monitor the speed of the genny, to see if it's going above 3600 RPMs. I think it needs to hit much higher for it to shutdown for overspeed... Hope this helps... I got really good troubleshooting. The early board did have some issues. There are a couple of different replacement boards, you want a later one if you think it needs to be replaced.. Regards, Don
Click to expand...


There's a schematic for the overspeed board that can confirm which wire to move to T3...
 
Another vote for the governor. It's a pain to get to and more of a pain to maintain. It's a poor design at best. Try to remove as much oil as possible withe a basting syringe. Then fill the same amount you removed with a clean syringe. Run the Gennie. Do this a few times. Your governor oil won't be perfectly clean, but it will be better than what you removed. After that, add a few drops as its running. I honestly do not recall where the visibility line is for the governor, but I know from expensive experience that it is a likely first culprit for your problem. YMMV. HTH Good luck.
 
the govenor was my problem last year. its mounted high upand easy to get at. just in my boat you have to pretty much stand in the rear bilge
 
UPDATE:

Went to the boat tonight and removed the governor. No Oil...literally none. Filled with some fresh oil, drained, and repeated a few times until it was clear coming out the drain.

Noticed it leaking oil from a seal arond the linkage. Cleaned it up and now its sitting in the upright position with a shotglass under the seal to catch the oil leaking. If it only leaks a few drops overnight I'm going to put it back on the generator to see if this no oil situation was causing the original issue with the overspeed shutdown.

I've looked for a rebuild kit for this governor with no luck. Will the Westerbeke service techs be able to order the parts to repair this or do I have to buy a new one?

Anyone have one of these rebuilt?

Thanks for the ideas and I'm hoping I can give the people who called "governor" a pat on the back. I'll post after I've tested tomorrow night.
 
I've been told that a decent mechanic/machinist can do a complete rebuild of the seals/shaft with (mostly) stock parts from NAPA and milling a new shaft, but I'm going to be sending mine out for a rebuild by a guy who sells/services Westerbekes. I'll try to find the contact information for you, but I'll have limited access the next couple of days.

There aren't any good sources for parts, this item was discontinued long ago, and a replacement costs upwards of $1800 just about anywhere I could find it. I've considered moving to an electronic governor as a replacement.
 
The governor leaked no oil last night so I think it's safe to re-install. I have a line out on a rebuild kit, waiting on reply. If anyone else knows of a place that rebuilds these governors please let me know. I'll update the post laser.
 
Here is a source for other parts that will save you a ton. Great customer service. They have walked me through a lot of things on the phone and with me sending them pix of parts. My former 4.5 was a Mitsu minitruck engine. The fellow said he surprised a lot of boaters.

http://www.fgpstore.com/default.asp

Still looking for the used westerbeke shop for you. I know there is one near Lake Havasu.
 
FOUND IT! Lake Powell not Havasu.

KISMET Marine. 1-888-956-6946

No affiliation on my part. I was very impressed with the customer service when I was having all kinds of troubles with my 4.5. The rep was on a business trip and called during a layover after checking his voicemail. Very personable and he told me what to check before he'd let me drop a dime. Come to think of it, he was the one who told me about the oil in the governor.

They may have one in stock that, if the money is right, order and do the R/R and ship your core back for a holding fee on a credit card. Worth a shot.

HTH
 
UPDATE:

Same Thing...Ran for an hour shut down on overspeed.

The governor had plenty of fresh oil and was at the proper 3 oz level.

I fired it up & let it warm for 5 minutes, I then let it run under medium load using the water heater, AC, battery charger and refrigerator. It worked perfectly. 1 hour.

I was changing belts on the inboards in the ER and listening to the generator operate, waiting for it to overspeed. The governor adjusted RPM for load conditions, like when the AC turned off or the hot water heater kicked in. Each time the demand for electricity changed the governor did it's job.

Then just as I was about to declare victory, I heard the AC cycle off, the generator speed increased, and then it shut down with the overspeed fault. Nothing overheated, plenty of oil and I could rest my hand on the exhaust elbow when it shut down. I reset the overspeed shutdown and it fired right up again. As before, from the generator I was able to press the Stop Switch, reset the overspeed fault, and keep the generator running by holding the pre heat button and overriding the safetys.

I also noticed that earlier in the day when I was testing I brought the generator up to operating temperature, added a load and ran it for a half hour. I was turning off the breakers one by one to listen for the increase in RPMs. On the last breaker as I shut off the AC, the generator revved up shut down on overspeed.

The governor appears to be doing it's job in the beginning. What I don't get is why holding the preheat switch keeps the generator from overspeeding? I know that the safetys are being by passed and as long as I hold the preheat switch the generator will continue to run without overspeeding and deliver a proper load. I would think that holding down the preheat would override the safety from shutting down the engine BUT the generator would continue to overspeed while the switch was depressed. Just like how the generator would continue to run with low oil pressure, or while it's overheating as long as the switch is being held.

David, thanks for the information on the parts and dealer info. We have a dealer here, they wanted $600 for the remanned Governor. I'll call your guy Monday.

More later.
 
David,

I spoke with Mike at KISMET and he's pretty sure it's the governor. I've removed it from the generator and shipped it to him where it's now sitting awaiting a rebuild. Mike said it would cost around $500 to rebuild mine and that the aftermarket governors were not the way to go. I'll let you know how it goes after I get it back and install it on the generator.
 
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