I checked all my battery connections today (actually, I removed my batteries today), and all the wires look new(ish):
Thanks for the download LSG, I have the manual already (as well a couple diesel repair books), but until I actually begin to turn some wrenches it still presents a cloudy picture to me. I learn mechanical stuff best in a hands on fashion.
If I pull the motor and take it to my local Yanmar service/sales center, what do you think an overhaul might run me? Any idea of a ballpark on something like that? I'd like to get her done just for my own piece of mind even if she is ok for the most part...
I cannot help with the prices because its been a long time since I worked in an automotive machine shop. Also, I do almost all my own work except when really expensive specialize equipment is required and I get my parts mostly online at wholesale prices so what happens is I really underestimate the cost for the average person. If I had to pay shop prices I could not afford my old cars and toys for all the work they have needed.
If I were you, I would strip the accessories from the engine; generator, injection pump, water pumps, manifolds etc. Strip it down to what is called a long block with the head and pan still on it and take it straight to an automotive machine shop. If anything is needed in the way of machine work, this is where the Yanmar dealer would send it anyway so cut out the middle man. But, I would only do this if the engine had low compression and failed an oil analysis test with a bunch of metal in the oil. Since periodic maintenance was done, you likely do not have any bearing problems from dirt and contamination in the oil. If there are serious bearing problems, they make a noise that gets worse with time. I doubt the engine ever ran without oil if well maintained. It all comes down to compression I think. These engine jobs can be expensive, so ask how much to do a valve job and how much to do a short block (grind the crankshaft, camshaft bearings, rebuild the connecting rods, clean all the parts, also ask how much a rebuild parts kit including all gaskets would cost if the machine shop supplied those items for you). Ask the machine shop if they work on diesel engines when you first call them up. If it's just gasoline engines, find another. You could also ask if they know Yanmar. If it's just low compression, then pull the head yourself.