Put a few more pieces back on the Yanmar today. The "engine room" on an aft cabin Nor'Sea 27 is a torture chamber. The engine resides under the cockpit; the forward end of it is accessed from the back of the forward cabin by removing the companionway ladder. The aft end is accessed from the aft cabin by (you guessed it) removing the companionway ladder.
Most of my tools reside in the forward cabin, so the general process is: go to the forward cabin, put on some part, put in the forward bolts, put in the companionway ladder, go to the aft cabin, start the after bolts...
go back to the forward cabin for the tool I forgot...
Lather, rinse, repeat.
All this is made more entertaining by the fact that winter has us in a firm grip, with highs about five below zero C and lows about -9. I'm running a little portable camping propane heater to keep it reasonably comfortable. Given this, everytime I move from one cabin to the other it's open the hatch, lift out the drop boards, curse the drop boards, reinstall the drop boards, close the hatch, go to the other cabin, open the hatch, remove the drop boards, curse the drop boards, clamber into the cabin... you get the picture.
Makes no difference. I'm making some progress, that's all that matters. I don't know for sure if it will run when reassembled, but it ought to. The valves were horribly burned and pitted, and now they're smooth as can be. There's not that much to a diesel.
Oh, Paul - re, old, slow turning diesels: This is a 1979 Yanmar that peaks out at 1800 rpm and doesn't produce much power doing that. But I'm not planning to T the return line anyway. To my way of fiddling it'll be easier to create a return line fitting. There's no pressure on it so it won't be stressed in use.