Looking at 38ac's "The twin build" thread, it looks like I need to work on my gibb key fit and maybe some day add the fuel pump cam oilers. I definitely need to make a guard over the front flywheel and gibb key. When starting, it is very dangerous reaching into the shed to turn the compression release levers, especially when there is ice or water on the ground (which is when the power goes out!).
Some lessons learned the hard way:
1) Don't wrap your thumb around the crank handle opposite the rest of your fingers.
2) When I first got the generator spinning, I wasn't getting any voltage on the output terminals. It had been sitting so long since being shipped, I thought maybe it needed to flash the field, so I tried that. Still nothing. Then I started taking the control box and wiring apart. There was one wire that was a little loose, so fixed that but still nothing. Looked all around inside and at the brushes. measured all the resistance of all the coils. Lots of google searching and reading about AC generators. The little meter on top of the generator showed voltage but I didn't have any at the terminals. I didn't know if the little meter on top was just an indicator of some sort and not really a voltmeter. Then one day I was out running it and switched the digital voltmeter on and selected AC. That's when I noticed I had been turning it onto the 200V AC scale, so it was showing -- instead of 230 or 240. It's a good thing I never touched the connections by accident.
3) With the milk can about 4 feet higher than the engine, after sitting a while, the gaskets on the cylinder blocks would seep coolant. I tried the radiator flake sealer stuff but it didn't help. I had to replace the gaskets on the doors on the sides of the cylinder blocks. They are too close together on the twin to remove the bolts. I had to loosen the bolts enough to cut the heads off, then the other side could be removed. Then use shorter bolts and grind the heads thinner when putting back together. Still seepage at the bottom of the cylinder blocks, so probably also leaking inside too. That was when I added the ball valves at the coolant inlet and outlet. I got lucky and found two large high quality 300 degree ball valves at Harbor Freight on clearance for only $10 each. I had ground out the outlet manifold to fit NAPA 190 degree thermostats. I don't know why, but one day I was doing a short test run and did not open the lower valve on the water inlet. I opened the top valve for some reason, but not the bottom. I was inside the shed fooling with something on the generator and the next thing I knew I was covered with anti-freeze spraying out of the engine. The cylinder block water jacket cracked from the pressure of the water heating and the thermostats must have sealed good.