I am posting this to help anyone who has a Solo they want to tune up. Since very limited parts are available from Germany, I will be posting updates on the Solo as I go.
To start out: I bought a 15mm Bing made for Puch with the high flow filter. The carb and filter fit perfect and snug up to the lower frame where the kickstand is. I am still running on the stock intake with a shim made from the hose that is on the stock air box. Use the side on the airbox, it fits the intake great. The hose needed just a little more to fit the carb right so I used two wraps of electrical tape to finish the shim up. I had to trim back about a