The deepest I've gone on the engine is the removal of the cylinder head. I described in this post why I am doing this much work on the engine. I had concerns about the head gasket and the head itself after running the engine overheated a while back. I poured over books, forums, spoke to the pros and developed my game plan to get the engine back in order. At this point, I only need to order a few extra parts that I haven't already and it will be ready to be reassembled. Nearly everything on the engine was relatively easy to take apart, with the exception of areas with corroded and/or worn bolts. Everything I've taken apart has been thoroughly cleaned, inspected and prepared for reassembly and painting.
The toughest part came when I started the process of removing the cylinder head. I first needed to remove the injectors, which are tricky little buggers requiring some ingenuity to pull out. These are not threaded in, and once they are in there they are pretty snug. I developed a custom injector puller after much research and credit this video for the help.
The injectors (click on any picture for a full size version):
Removed, dirty injectors:
I then took the injectors to a pro to get cleaned, inspected and tested. One injector had to be fully replaced, the others needed some work but ended up OK:
Next up was the removal of the cylinder head. First the valve cover came off, the rocker arm assembly removed, and the head bolts loosened in the correct order:
Once the head was off I took it to the pros to get a valve job done, the head checked for warpage, and a full cleaning. Turns out the head was pretty warped, as I was fearful of, and they had to machine it flat again. Fortunately, that wasn't too bad $$ wise and the head came back looking shiny and ready to roll.
Cleaning the gasket off the block was a pain, particularly when trying to not scratch the surface and avoiding having pieces of the gasket falling into the engine holes. But I eventually got it all cleaned off, and she is now ready to be put back together.
I've ordered and received most of the parts I will need, however, the list of needed parts has grown a little bit since I put in that order. I resigned myself to ordering some of the hoses from Yanmar, as many have custom bends in them that I cannot make with regular engine hose. For a length of 6" of hose, Yanmar charges $25 just because it has a custom bend in it! Oh well. Once the parts are in I will torque down the head, get the valve clearances squared away, and begin to reassemble and paint.