Thanks Tazza and Farmshop! Well some good news today, I received the thermostat and so was able to put it in and test her out. I was lazy and did not repeat the compression test or check for valve clearances. Well, after priming she fired right up. There was some white smoke but not a huge amount. There seems to be some blow by but not a huge amount (although I don't know what is a lot). The first cylinder temp is still low, but not as low (maybe about 185 when the other cylinders are 200). Upon revving up, there is now no hesitation, no knocking and black smoke, just a bit of white smoke after hitting the throttle, then goes away (mostly, there are still some fumes). In contrast, when I got the machine 2 weeks ago, it was very, very hard to start, then poured black smoke (probably masked the white smoke), then white smoke, and would knock and pour black smoke when going past 1/2 throttle. So in summary, although the engine doesn't seem new and has some signs of wear, I'm thinking it might be ok to run it like it is (the engine at least!). Well, I didn't mention the rockers with uneven wear, but will save for another day. I did bugger up two of the injectors (a brass washer on the injector for cylinder 1, and the thing that has the return hoses for the injector on cylinder 2), and will need to address.
During replacement of the thermostat (or more accurately, adding the previously non-existent thermostat!), I flushed the coolant, and upon removing the coolant hose to the overflow tank, discovered that the copper nipple where that hose attaches to the radiator (just below the radiator cap) had broken off! So once the coolant heats up, it pushes against the cap and instead of going down the overflow hose in to the overflow reservoir, pours down into the engine compartment and on top of the battery! Just another sign of the lack of attention from the previous owner, or a pessimist might even think deception from the previous seller (and my lack of careful evaluation before purchasing). I attempted a repair, using a propane torch, flux and solder, and it seemed to work, we'll see if it holds up (it seems to be holding after 10 minutes of driving).
Tazza, my compression gauge is so cheap, I can't be sure that the 420 reading was accurate. But will hope it is!
Farmshop, thanks, I'll keep an eye on the coolant levels, and if they drop, will start stressing about how to do a leak down test...!
I'll try her out tomorrow, and if good, will just focus on fixing the injector seals, and then call the engine fixed enough for me, for now. I would like to express my sincere thanks to Farmshop, Tazza, and this forum for the help on this problem in particular, and general helpful suggestions in this forum over the years. It's really helpful for unknowledgeable guys like me...!
