Westerbeke 4.5 BCGB Issues, any advice?

I will answer my own question since I changed plugs yesterday. Size is 13/16 and mine had NGK BPR5ES plugs. That’s what I put back in it. To answer the question above about the swivel, use electrical tape around the swivel joint to firm it up. Mine already had tape but I had to add Some more To get the job done. Was a pretty quick process to change the plugs. I did that and added some oil to the governor. All good so far but I have not run it more that 30 minutes.

EDIT: I still had my low voltage issue with one
AC unit (two different brands) I checked the belts, the governor belt was on the loose side, tightened it, the voltage came up and was more stable. AC has not kicked off/given low voltage alert since tightening belt.

Can someone enlighten me as to what spark plugs the 4.5 Westerbeke takes ? Similar issue and I want to inspect/replace plugs first as I start this process. Yea !! :)
 
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2002 340 Sundancer w/Westerbeke 4.5 BCGB <-- ~1200 hours.

Generator runs normally (as it has done the last 7 years that I've owned it) and then suddenly just shuts down. It will run 4, 5, 6 hours at a time, then die and won't restart. The next weekend I come down to the boat it does the same thing again...day 1 runs 4 hours no problem. Day 2 it runs 6 hours and then suddenly dies and won't restart (usually in the middle of the night like 2am). When it dies/shuts down it doesn't sputter or anything, it's like someone hit the run switch and turned it off.

This has happened 3 times so far this season, and when you try to restart it will start and run for about 5 seconds and then immediately shut down again but it will only do this 1 time per weekend. For instance, it will die, I will try to restart, crank several times, no firing no nothing. Then wait 2 hours. Try again, nothing, wait 5 minutes, try again, nothing, wait 5 minutes, try again, fires right up and runs for 5 seconds and shuts down, try again, nothing, wait 5 minutes, try again, nothing, wait until next day, try again, nothing, wait until next weekend, tray again fires right up and runs 4 hours. You kinda get the picture.

What I have done so far to troubleshoot:
  1. In June replaced cap & rotor (for the 1st time ever) and spark plugs because it died and wouldn't restart for the first time and when I spark tested I found 1 of the 3 cylinders was not getting spark. The contacts in the cap looked pretty worn and a little bit corroded so it was not surprising. This fixed the issue. It then ran fine for about a month or 50 hours total.
  2. New ignition coil in July. When replacing cap & rotor & plugs I noticed the spark looked a little weak on my spark tester so I figured this should probably be replaced once it started acting up again. I did not use the Westerbeke OEM part for $430 but instead used a very similar Delphi GN10170 general purpose coil from Amazon for $20. Works fine but seems it did not fix the issue.
  3. Checked the carb fuel filter and found to be in good condition. I had replaced this just last season (2019) with the OEM WB part so I expected it to be good.
  4. Disconnected the fuel line into the carb and hit the ON/preheat switch. The fuel pump is pumping plenty of fuel out of the line.
  5. Measured battery voltage to the fuel cut-off solenoid as good when cranking. Removed the solenoid and tested with wires to B+ and GND, the solenoid actuated. Cleaned it with carb cleaner.
  6. Plugged the hole where the fuel cut-off solenoid goes and the generator started and ran although very rich (understandably). I thought wow maybe it's bad but when I put it back in the generator also started and ran several hours making me think the fuel cut-off solenoid is OK. Also the local WB service shop near Lake Cumberland (Unlimited Marine) told me they have never encountered a bad/failed fuel cut-off solenoid and therefore don't stock that part.
  7. Tested the K1 and K2 relays. They actuated and the coil resistance is in range (86 Ohms for one and 87 Ohms for the other), so these should be good.
  8. Checked oil level and found to be OK.
  9. Raw water pump impeller is OK (new last season, pumps water just fine when the generator is running).
I don't think it's any of the safety shutdown switches. My understanding is these are bypassed when holding the ON/preheat switch to allow the generator to start anyway, so with it not even starting, even after cooled down, I think the safety switches are OK.

My only guess at this point is maybe the fuel cut-off solenoid is intermittent. Obviously something is intermittent causing this to happen, I just can't figure out what it is.

If you've hung on and read this entire thread, I'd appreciate if you have any educated guesses as to what could be causing the trouble, or if you have any idea of the typical things that fail on a 18 yo ~1200 hr 4.5 BCGB 3-cyl Mitsubishi engine that maybe I haven't checked yet.

Thanks,
Brian

Hey Brian!

I see this is an old post, but was wondering how your boat performs with the 6.2’s?

I have a 2000 340 with the 454 horizons and vdrives. So water ingestion issues got me to the point of rebuilds (not crazy about that) or new power.

Any cruising stats you have would be great! Cursing rpm/speed WOT rpm/speed.

Thank you!
-Matt
 
How the hell did we go from a little red generator to mercruiser 6.2L motors. New thread is needed.
 
Because Jambrin, the person who started the thread, has the generator in his 340 Sundancer which has 6.2’s. I couldn’t figure out how to send him a direct message so… Here we are.
 
Click on his name “jambrin” then click “start a conversation”. He hasn’t been here for over a year though



5252BA8F-82E4-4A7F-B214-211C399DA0A3.jpeg
5252BA8F-82E4-4A7F-B214-211C399DA0A3.jpeg

Because Jambrin, the person who started the thread, has the generator in his 340 Sundancer which has 6.2’s. I couldn’t figure out how to send him a direct message so… Here we are.
 
I had to use an extension and swivel to get on the spark plugs. Seems impossible at first but it can be done. You have to position the swivel so that the spark plug socket angles towards the spark plug. The problem I had was the swivel would move too easily, meaning I would set the swivel in position to angle the socket towards the spark plug and then by the time I got it close to the spark plug it would move from the weight of the socket pulling down on it, changing the angle and not allowing the socket to go on the plug. If you could get a swivel that has some resistance to it (not sure that exists) or maybe put some putty or something on the swivel to make it hold the angle it would help. I didn’t have anything with me so I just used my other hand to hold the swivel position/angle as best I could. It took multiple attempts per plug. It wasn’t too terrible though since there are only 3 plugs.

Some things that helped me figure out the correct angle is using a mirror, feeling around with my fingers (difficult because tight space) and using an endoscope. I have an inexpensive endoscope that I bought from Amazon a couple of years ago. It has an app on my phone so you can see the video and it’s been helpful to observe some tight or inaccessible spaces a few times while working on the boat.

Good luck,
Brian
Welcome to the club. I've been fighting the spark plug issue myself. Going next week to try again with a 13/16" socket turned down to 1.0 inch and a 3/8 drive wobble extension instead of a swivel. This is a common problem and I've heard the wobble will make it happen, sure hope so.
 
I see you do your work and I’m in the same situation. I’m dealing with the same scenario. And trying to check my plugs, I can’t get on them. Is there a trick? Appreciate your help in advance
Thank you
Larry
I fought the elusive spark plug removal as well and finally got on them pretty easily with a wobble extension. Works better than a swivel as the "wobbling" is limited.
 

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