Westerbeke (westerbreak) stops running after 30 to 60 minutes of running

kevin27 said:
I had as simular problem on a gen set and it was the fuel pump. As the pump heated up from use it would stop working. Also I had the same gen in my 300da and had some problems with it early on with the fuel pump. Replace the fuel pump first. I think it may fix your problems and is not that expensive. You can also check to see if it has pressure when it quits by leaving the run switch on and cracking the fuel line at the carb to see it you have gas there. It won't be much pressure, I think it's like 4psi but should have some flow. Hope this helps.
Click to expand...

Kevin I agree with you, but I am not committing to a fuel pump problem because the pump is new. It probably has less than 5 hours on it. Now, I must mention this problem started right after I changed it. As a result, I think I should be looking at it as possible problem, just as you suggest.
 
I'm still troubled that a safety is tripping which is why it shuts down after running for 30 minutes or so.

1) Did you have a chance to check the temps of the block and exhaust manifold with an IR temp tester?

2) Have you bypassed each of the sensors once it shuts down to see if it restarts? If you check or bypass them one by one, you will know for certain if one has been tripped. Both temp sensors if tripped/hot will have no resistance across their terminals (closed). The oil sensor is normally closed to ground until the engine is started. The pre-heat switch bypasses it until oil pressure builds up to keep it open.

3) If you have eliminated the safety's, the next likely candidate is the fuel system. I haven't seen a fuel problem behaving as you described the shutdown but it is very easy to test. The fuel solenoid is normally in a closed position. 12volts energizes the solenoid holding it open during the preheat cycle. The control board then applies voltage to keep it open as long as the safetys have not been tripped. The only way to check the fuel pump with out creating a hazard is with a pressure gauge. It will only pressurize to 3-4lbs so you need a very low pressure fuel gauge.

4) Broken wire or bad crimp. This is a hard problem to find and very frustrating. When the unit is running, pull on the harness at various locations (including the safety's) where there are connections. If it is a bad connection, the unit usually shuts down right away. I have worked on two Westerbeke's where your symptoms matched a bad/corroded connection.

-John
 
Hi John,

Thanks to you all for taking some time to help me out. John, the highest temps got are as follows;

Exhaust mainifold 182
Elbow 85
Heat exchanger 125-135 depending location
Block 155-180 depending location
Thermostat housing 168
Fuel pump 86
 
Based on my engines temps are correct but mine are gas.
Based on the fact it takes 30 minutes to fail it could be a circuit board that is cracked and expands when warn and you loose connection in it. That is what happened on a car I had. New module was $500. A loose wire in a connection might do the same. I had a volt gauge on one engine that read 10 volts at full charge. For 2 years I looked for the problem and when I was working on an area I felt had nothing to do with the volt meter I found a loose connection screw. After tightening it I got 13 volts on the gauge.
 
Northern, mine is gas too.

It seems to be getting worse. Now it runs for about 20 minutes.
 
The temps are fine. I still would like you to check or bypass the sensors after the generator shuts itself down. The reason is a sensor can fail and I would hate for you to start diagnosing something else and miss a bad safety. It will only take a few minutes to check them and eliminate them from the problem list. While it is running, please tug on the various harnesses and connections to see if it shuts down. The specific connection that goes bad is the distributor feed that has a crimped spade connector in most harnesses. For some reason, the operating vibration causes the wire in the connector to break strands ultimately leaving only a few to make the connection. When it heats up, voltage drops to the distributor and the unit shuts down.

Northern is correct that the circuit board could be bad but I'm not there yet. I realize it is a pain to consistently be trying diagnostics but the problem will turn out to be simple.....finding it is the hard part.

Electrical issues are the hardest to diagnose on any generator. That's why when I have to fix one I eliminate all the safety issues first.

BTW all generators are constructed generally in the same way. Westerbeke, Kohler, Northern Lights, Quicksilver (Generac) all use similiar controls. In my experience, most suffer the same part failures over time. The biggest issue is that people don't use them and that creates a unique set of problems.

John
 
On my cast iron exhaust is a high temp solinoid. You probably have one. If it is faulty it could be your problem. Next time your generator fails disconnect the wires and see if the generator will start.
I have no other items I have done to mine.
 
PlayDate said:
The temps are fine. I still would like you to check or bypass the sensors after the generator shuts itself down. The reason is a sensor can fail and I would hate for you to start diagnosing something else and miss a bad safety. It will only take a few minutes to check them and eliminate them from the problem list. While it is running, please tug on the various harnesses and connections to see if it shuts down. The specific connection that goes bad is the distributor feed that has a crimped spade connector in most harnesses. For some reason, the operating vibration causes the wire in the connector to break strands ultimately leaving only a few to make the connection. When it heats up, voltage drops to the distributor and the unit shuts down.

Northern is correct that the circuit board could be bad but I'm not there yet. I realize it is a pain to consistently be trying diagnostics but the problem will turn out to be simple.....finding it is the hard part.

Electrical issues are the hardest to diagnose on any generator. That's why when I have to fix one I eliminate all the safety issues first.

BTW all generators are constructed generally in the same way. Westerbeke, Kohler, Northern Lights, Quicksilver (Generac) all use similiar controls. In my experience, most suffer the same part failures over time. The biggest issue is that people don't use them and that creates a unique set of problems.

John
Click to expand...

Agree.

Will check safety sensors as soon as I have a minute to spend on the genny. Will report findings.

In regard to the distributor feed connection, I noticed these are beat up and I have verified they are connected. I plan to refurbish this connection with new connectors as soon as I can buy the correct spades.

Also, will check the inline fuel filter at the carb. On that note, could I be needing a carb rebuild?
 
"On that note, could I be needing a carb rebuild?"

If it is not surging while it is running and it holds a load.....rebuilding the carb won't help. Carb issues spew black smoke (rich) and a lean condition won't hold a load. A quick look at a spark plug will tell you if there is a problem.

I still think the problem is electrical. Once you eliminate the safety's and the basic wiring connections we can move on to fuel. On that subject, why did you replace the fuel pump (mentioned in an earlier post)? You also indicated that the shutdown problem started to occur after the pump was replaced....is that right?

-John
 
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Having the same problem with my Quicksilver 7.5. Driving me nuts. Runs fine for 1-2 hours at the dock, with or without load, only runs 20-40 minutes underway.
 
I had a similar situation with an Onan 3kw gennie on my 290DA. It would start and run great then quit after 10-15 min. After lots and lots of troubleshooting (and part changing) it was the fuel pump. A very helpful tech told me to have a jumper wire from the battery + at the ready when the gennie quit. Jump to fuel pump + as soon it quits and listen for the fuel pump to "whine" (indicating it is working). Mine was dead silent......new fuel pump fixed it.
I know your pump is new but it's an easy test to do.
 
PlayDate said:
"On that note, could I be needing a carb rebuild?"

If it is not surging while it is running and it holds a load.....rebuilding the carb won't help. Carb issues spew black smoke (rich) and a lean condition won't hold a load. A quick look at a spark plug will tell you if there is a problem.

I still think the problem is electrical. Once you eliminate the safety's and the basic wiring connections we can move on to fuel. On that subject, why did you replace the fuel pump (mentioned in an earlier post)? You also indicated that the shutdown problem started to occur after the pump was replaced....is that right?

-John
Click to expand...

Hi John,

I replaced the pump because it stopped working. It would not "click" and therefore genny would not start. Thanks for the input on the carb.
 
Quint4 said:
I had a similar situation with an Onan 3kw gennie on my 290DA. It would start and run great then quit after 10-15 min. After lots and lots of troubleshooting (and part changing) it was the fuel pump. A very helpful tech told me to have a jumper wire from the battery + at the ready when the gennie quit. Jump to fuel pump + as soon it quits and listen for the fuel pump to "whine" (indicating it is working). Mine was dead silent......new fuel pump fixed it.
I know your pump is new but it's an easy test to do.
Click to expand...

Thanks Quint,

The pump "clicks" after shut down using the preheat button, so I belive its working. I will try your suggested test, with a twist. I will run a + lead to the pump and see if its an "enough juice" issue. My volt meter shows 12 volts, but I have not tested at time of shut down.
 
When you first start it does the warm up button work? If I was you I would get a schematic and trace all circuit boards and wires in th estart and run paths. I however would consider changing the over speed board, not for the over speed circuitry, but for the connections which pass through the circuit board. It sounds like you may have a circuit trace or connection expanding and allowing a relay to open/close (based on configuration) when it should not be doing so.

The warm-up button does not allow any warming, what it typically does is complete the circuit path from you battery when you are starting are starting up the generator to pass through your safety items, once the generator is running then it typically has a 12 VDC circuit which kicks in and supplies voltage through the circuit path.

If I was you I would be looking for a connection which is opening once the generator has heated up, thus your warm-up button will not re-start the generator, until the connection cools down, and remakes contact.
 
Well I had the thing running for over an hour today. I am not calling victory yet, but I am feeling better about it. Two things that I adjusted that could play a role.

1) I noticed the belt for the pumps was loose. As a result, maybe as the belt heated up and stretched it lost contact with the circulating pump and caused the coolant temp to go up enough to trip the safety switches.
2) After reading threads about air in fuel line here in SRC, I checked all fuel connections and tighten a few that might have been loose.

The result is that it ran longer than its run in a while. I was forced to stop the genny couse I had to go. I will try later when I have more time.
 
It's always something simple when you find it. Sounds like the belt may have been the issue. It matches the symptoms. I hope that's it.

-John
 
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