Motorcycles, Snowmobiles, Go-Carts, ATV's and Golf Carts - yt60 running problem

I have a 1984 Yamaha YT60 Tri Moto. I have owned it since it was brand new. It has been sitting in the garage for a few years and I decided to get it running again. Here's the deal. It will start but only runs with the idle screw all the way in. If you give it throttle, it bogs down but will idle if you let off the throttle. Here is what I have done so far but with kittle success. Flushed the fuel tank, cleaned the petcock filters, completely cleaned the carb (I mean completely!), new OEM spark plug and coil wire cap, cleaned and lubed all wire connectors, cleaned/lubed the start/run/off switch, cleaned/lubed coil mounts, sprayed silicone spray around base/head & intake gaskets (looking for increased idle...none) while engine was running, laid spark plug against the head with coil cap on & pull stated it (it showed dimiutive blue spark) because the switch must be in the 'start' position, and the choke system (cable/brass plunger works fine) I have been working on it a while, anyone have any idea to help?