There´s an aftermarket one on eBay for about $50 - you can probably swap in the correct jets and it should work, although I haven´t tried it myself. I recently bought a spare engine for my Twinstar, which included a carb, but the jack-ass seller didn´t remove it before shipping and packed it very inadequately, so the carb was crushed in transit :( What happened to the carb? You can usually just clean it out, unless you suffered some catastrophic damage.