Well, I made up a drain plug hex tool by welding a 20mm nut to an old 1/2 drive socket and it worked great. My dad and I drained the diesel out of the main clutch compartment and started the D-2 up. The pony motor ran a little rough at first, but then ran clean and strong. We spun the diesel a good long while before adding fuel and firing her up. She runs very smooth and sounds great, tons of oil pressure.
However, the main clutch continued to refuse to break free even after sitting in diesel for a month, which sounds pretty scary- it's a shame I will have to pull the engine to sort that out, when the engine itself seems to need minimal work.
Question about the main clutch- actually I have two:
1. How in the hell does this thing work? It seems like the clutch lever does two things- separates the clutch plates and slides the clutch off a spline shaft from the trans; is this accurate?
2. If the main clutch is frozen, would it be possible to start the engine in gear any way, as the steering clutches are not connecting the tranny to the sprockets until they are engaged? This would allow me to move her onto a trailer and off, which I need to do pretty soon. It would seem that physically, there is no reason that this should not work.
Regarding the engine, it is amazing to me that this thing runs as good as it does; as far as we know, it has never had a valve job and the rings were changed once about 20 years ago. Dad says it seems clear to him that it has been losing power, though the exhaust is clear and she does sound really good. I figure she needs a valve job and a set of rings.
Thanks for any help you can provide.