Monday, February 9, 2015

Return of the Beast

Spent more time looking at the stubborn starboard Westerbeke engine today. While it was starting a bit better, it is still a long way from right.  So I crawled back down into the engine room with my trusty flashlight, inspection mirror, paper towels, and a wrench.

I looked at all of the fuel system I could see and didn't find any leaks.  I checked every fitting I could get a wrench on and they were all tight.  I ran paper towels over the lines and found no leaks. Since the engine runs fine once it gets running, I've ruled out airflow (which I think would cause black smoke) and compression (since it does run fine once it is running) so that only leaves fuel issues.  But I'm stumped.

Of course, during my inspection, I found that one of the coolant hoses was chafing on a couple of the engine bolts.  So I did find something to fix.  This hose is molded to fit the engine a specific way and appears to be installed correctly, so I don't know if this is just bad design or what. In any case, bolts rubbing through a coolant hose is bad, so I needed to do something about it.

I was able to get a piece of scrap reinforced hose and so I cut a couple patches to act as chafe protection for the hose.  I used some high temp RTV to glue them onto the hose and temporarily secured them with zip ties to allow the RTV to set up.  Please note, if you ever try this, you must remove the zip ties...I've seen them cut through metal aircraft engine mounts so I have no doubt that they would make quick work of a rubber hose if left in place.  Hopefully the added reinforced rubber will give this hose some added lifetime.

So, still no joy on the engine starting issue, but at least I may have prevented, or at least significantly slowed down, another potential problem.  One of these days I'll hopefully solve this little Wester-Beast problem.

7 comments:

  1. Hi Mike,
    Have you tried replacing the glow plugs? I had an early 60's tractor which never liked starting cold. A friend suggested to replace the glow plugs which I tried, and it then would fire up (almost) straight away. The old glow plugs hadn't failed, they just didn't work as well.
    cheers,
    Alan

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    1. Thanks Alan. When the tractor was stubborn, did it smoke while you tried to start it, or was nothing coming out of the exhaust? In my case, I don't see anything out of the exhaust until it is close to starting, then will finally see some wisps of smoke just before it finally starts.

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    2. I can't remember seeing any smoke, but I think that is more a result of my not looking rather than nothing coming out. I also use to spray Aero Start in the air intake (easy to do on tractor) to help it fire up easier. After the glow plug replacement, it wasn't needed.

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  2. Hi Mike,
    In reading about Westerbeke 42b engines, seems they have some issues concerning too small exhaust (must be at least 3" dia) otherwise high, 10psi or higher backpressure. The backpressure may cause rough starting but also overheating especially on cyls 3 and 4 with resultant damage to rings and loss of compression (low 100 psi) in those cyls. Long engine running times, ie ICW, can lead to these problems. Have you checked exhaust dia and cyl compression?
    Doug In VT

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    1. Hi Doug,

      Hope you are staying warm in VT. 3 inch diameter...that's huge for a 42 hp motor. Eyeballing the exhaust manifold outlet, I'd guess it is less than 2" diameter...and the rest of my exhaust system appears to be 2". I'll see if I can pull the hose and inspect for buildup. When it runs, the motor runs cleanly, so I don't expect I'll find much.

      Other than the one overheat incident a year ago, the running temps are in the low 170's (verified with a non-contact thermometer) and the engine runs smoothly at all RPM's, so there isn't any other evidence of compression issues...but if I can't figure out anything else it may be time to get a compression test.

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    2. Info I got was via sailnet website, google search westerbeke 42b. Several mentions of too small exhaust and Westerbeke recommended changes. Seems cyls 3 and 4 don't exhaust completely due to high back pressure leading to soot build up leading to ring failure,wall scouring, low compression/hard starting. The Westerbeke online manual does mention a lot of causes including the glowplug item noted. Don't mean to be a downer but compression check may be in order. Harbor Freight has $30 and $180 versions but no idea if they fit Westerbeke. Or a marine mechanic
      Doug in VT

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    3. Hey Doug, Yeah, they seem to mention changes and problems...but not any details of those changes. One Catalina owners group had an article, but you had to sign up to see it...and they probably don't want a Leopard owner on their group. So, all I can tell about the info is that it may be from installs several years older than mine and hope that whatever changes have been made. That and it seemed like all the reports are from catalinas so I wonder if that particular install was troublesome.

      Given the symptoms, I'm not ready to rule out the fuel issue yet. Rebuilding the engine is an expensive last resort. Will see if I can find a way to run a compression test...if I can find an adapter for the glow plug hole...can test them at that time as well.

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