I have a question about the engine in the title. With a 12/7 APC prop and Eric Clutton's Old English Diesel fuel I can over compress the engine but not under compress it. At least I'll get to the point where I don't dare to back the compression screw out any further. Is the engine under propped? Another possibility could be too much ether, I doped the gallon can (most of the gallon unused) with the contents of a can of John Deere starter fluid. A Norvel 061 with an RJL head would not start before it was added.
Today I ran an OS 10 FP with a Davis head and it would miss as I backed the compression down. I'm a little confused about the .40. Ted