The replacement cylinder needed to be soda-blasted though, to match the other cylinders. It is currently at the blasting shop, awaiting exterior cleaning. Below is one of the new pistons, with wrist pin, small end bearings, and rings.
Below is the center carb, partially torn down. Notice all the corrosion and gas varnish deposits. I should have drained everything last time I put the bike away. But at that time I didn't realize it would be put away for 20 years :)
I'm going with larger main jets, because it ran pretty lean when I added the expansion chambers. At that time I went from 77.5 to 85. This time I'm going to try 100. The main jet is for metering fuel at larger throttle openings. It's the little brass fitting on the main body of the carb above. Below are some replacements.
Anyhow, I've now refurbished (and polished) one carburetor. It took a couple of hours to de-gunk, refurbish, and polish.