Originally Posted by SteveP

I wouldn't touch the bottom end just yet. If it idles down eventually, then the low-speed needle is pretty close to where it needs to be. If it's staying at high idle after releasing the throttle, it's a strong indication that it's very lean on the high speed needle. Open up the main needle until the engine idles down properly - the bottom end will get a little richer by opening the main needle anyway.