You guys gotta start using the internet, I googled "CPI bullet 90", and got lots of info, including a website with a 36 page pdf file (only 18 pages total) showing all body, frame and electrical and engine parts with part numbers from Parts For Scooters ATVs buggies GoKarts Vespa Piaggio Kymco SYM PGO Aprilia Eton Apex Kinroad Carter
. This took me all of maybe 2 minutes to do, including typing out this post !! There were also several other sites to check out, just google it and you will find what you need, complete with part numbers.
As far as your idling problem, its probably the pilot jet gummed up, it controls fuel flow for idling, you need to take carb apart and clean it out, it probably sat a while and got all varnished up, thats why it will run with choke or full throttle, you are bypassing the idle circuit when you do that.