Sunday, April 28, 2019


It's hard to remember after so much work on the generator, that the original intent was only to change the oil.

Done, nearly
Nevertheless, here we are.  I got everything reassembled, with only a couple of difficult spots.

The first relief was that reinstalling the fuel line to the pump went a lot easier than when the filter end was firmly attached (I made up the filter connection, and then installed the filter...).  Everything else went pretty much by the book.

Old vs. New
But the new exhaust elbow caused a little difficulty because the water connection was rotated counterclockwise a little (see the little block bolted to the head at the far left in the 'old' view - where the wires go).  As a consequence, it interfered with the cylinder head over-temperature sensor.  But that was remedied by installing the sensor to another threaded hole in the head only an inch below the original.

The biggest problem was the wiring to the head over-temp sensor and the exhaust elbow over-temp sensor.  At the head sensor, there were two wires in the terminal (the sensors are in parallel - either can shut the engine down).  When I was sliding the connector on, one of the wires pulled out of the terminal.  It turns out that these are unusual terminals (read: Sebo's doesn't stock them), so I had to spend nearly an hour laboriously un-crimping the terminal and then re-crimping it with both wires firmly attached.


But I ran out of time.  I have bled the fuel system, but I still need to bleed the seawater side and refill the fresh water side of the engine.  Then I need to run it and look for:
  • Oil leaks
  • Exhaust leaks
  • Fresh water leaks
  • Salt water leaks
Hopefully there won't be any of these, and I can finally pull the curtains closed on this year's annual genset oil change.

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Thursday, April 25, 2019

Recursive Maintenance Continues

Maintenance recursiveness continues.

Being unable to budge the stubs left from grinding off the bolt heads, the only remedy was to remove the exhaust manifold/cooler to provide access for more drastic treatment of the bolt remainders than I could bring to bear with it in situ.

But...  before removing the exhaust manifold/cooler I had to drain both the antifreeze treated fresh water and the seawater from it.  This posed a problem because the genset and the heat pump share a thru hull, strainer and feed line.  Because it is still too cool here to do without the heat pump, I needed to install a shutoff valve in the genset seawater feed.

Genset seawater feed shutoff valve
This had it's own set of problems, first of which was a trip up into town to get some fittings.  Of course.  Despite the fact that I have a huge number of fittings aboard, none of them were suitable.  Then shut down the heat pump, close the seacock, cut the hose and clean up the mess from the drainage.  Finally, install the valve.

Draining the manifold/cooler
Now it was possible to drain the manifold.  Because Yanmar provided both drain petcocks and even drain hoses on the 2GMF, this was a clean job. 

And finally, removal of the now empty manifold was quite straightforward.

It turned out that the bolt stub removal was also easy...  because I took the manifold to Gustav at EngineTec here in Anacortes (highly recommended by Jason, and now I can add my enthusiastic recommendation as well).  An hour after I had dropped it off, Gustav called me telling me it was ready for pickup.  I barely had time to finish a post removal celebratory beer!

All I lack for reassembly is the gasket that goes between the manifold and the engine - currently on order.

I lay the blame for this incident at the feet of Kohler, the genset manufacturer.  Kohler adapted the Yanmar 2GMF to power the generator.  When they did so, one of the changes they had to make (in addition to relocating the oil filter) was to reorient the exhaust elbow.  The Yanmar elbow points straight down - that would have interfered with the generator body.

Kohler tilted the elbow to the right

So Kohler cut the elbow pipe off the flange and rewelded it at an angle to clear the generator body.  So far, so good.

The problem was that they made a dog's breakfast of it.  When the pipe was rewelded to the flange, the flange warped, making a seal against the manifold completely impossible.  Rather than redoing the weld, perhaps on a fresh, heavier flange, Kohler sealed the 1/8" gap using JB Weld or something similar applied to the manifold, and then to make sure, they installed two gaskets.  This all became obvious when I was able to inspect the manifold, and when I removed the gaskets and exposed the JB Weld (or whatever) on the manifold flange.  This crappy jury rig held for a while... perhaps 400 engine hours.  And then the leakage started.

Yanmar: 1
Kohler:   0

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Friday, April 12, 2019

Genset Stage Three

Heads ground off the bolts
As I mentioned previously, I intended to grind the heads off of the bolts.  I could not budge the two on the right with a wrench without risking twisting them off, and the two on the left had corroded to the point where their heads were just nubs.  The plan was to grind off the heads, remove the elbow, and then use ViceGrip pliers to grip the stubs and turn them out, if possible.  The only tool that I could get to bear on the bolts was a Dremel tool with a little 3/4" grinding head...  it took about an hour for each bolt.

It's off!

Amazingly, even with the bolt heads removed, I had to drive a screwdriver between the elbow and the exhaust manifold to free the elbow. Corrosion products completely filled up the space between the bolts and the holes in the elbow flange, bonding it tightly. This does not bode well for being able to remove the bolts...

The inner tube is loose

...And this tells part of the story. The inner pipe was loose and had been ejected part way down the hose that attaches to the exhaust elbow...

Warped flange

And this is the rest of the story: the near edge (the bottom) of the flange is significantly warped. Combined with the loose inner pipe (above), this meant that hot seawater would be leaking out of the bottom of the flange. That seawater was supposed to cascade down around the inner pipe and join the exhaust gases near the far end of the elbow. Instead it was right there at the warped flange.

New fuel pump installed
With the primary and time-limiting task out of the way and the old elbow shipped off to Ben at, I had more room to work and more time, so I installed the new fuel pump.

Shiny new exhaust elbow

Late breaking news: Ben has completed the new elbow and will be shipping it soon! Gotta get those bolt stubs out!

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Monday, April 1, 2019

Genset Saga Continues

Well, there has been a little progress.

Kohler oil filter stand-in

I have removed the remote oil filter mount, the (rusted out) oil lines and the heavy iron casting that Kohler installed to replace the oil filter and provide attachment points for the oil lines.  Holy cow!  That was not trivial work.  The banjo fittings at the oil line ends used 25 mm bolts, and it was pretty much everything I could muster in the confined space to break them loose.

As another example of Salnick’s Law of Recursive Maintenance, it was not possible to actually separate the oil lines from the engine because they were behind the water feed line to the sea water pump.  Since I had then to drain and disconnect the pump, this provided a perfect opportunity to replace the pump impeller.  The old impeller looked like it was new.

And while the pump was out I got the oil lines out, tho even with the water fed line out of the way it was still a complex geometry problem to unthread the lines in the cramped operation space.

Oil filter in Yanmar factory location (oil lines still in place)
In order to ensure that I had no leaks, I installed a new filter, reconnected the sea water line and fired up the genset.  There were no leaks, oil or water!

Next on the agenda:
  • Replace the corroded mess of a fuel lift pump
  • Remove the exhaust elbow and send it to the fabricator who will make me a new one out of 316SS.  This will not be easy.  Two of the bolts that hold the elbow on are corroded to the point that the heads are just nubs.  And of course these are the ones that are nearly impossible to get at.  To add, I can’t budge the other two... without risk of snapping them off. 

    My next plan is to use a Dremel tool to tediously grind off the heads of the bolts, remove the elbow and then use vice grips to attempt to remove the remaining “studs”.  Two of the bolts go into thru-holes in a flange on the block, so the worst case scenario there would be that they get drilled out and replaced with bolts and nuts.  The other two, the hardest to get at (naturally), go into blind holes...
And so the saga continues...

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