Finally got this puppy dialed in. Thanks to all who made suggestions. The secret was the idle channel on the bottom of the #24 Bing slide. Myrons Mopeds suggested filling in the channel with epoxy to richen up the idle. I completely filled it in, put in a .217 atomizer with #67 jet, and moved the needle to the bottom position for maximum richness. It's not perfect, but it runs strong and idles at about 4K RPMs. Would like to get it closer to 2k, but not sure it's worth it. Besides, at 50cc a high idle doesn't create that much vibration and it's not too loud. She's now a sweet little ride. Forgot to mention, I moved the condenser from beneath the flywheel to the stock outside coil for ease of access. Will post pics if anyone's interested.