You may have soft seized it. No replacement carb comes jetted specifically for your bike. On a two stroke, the oil for lubrication is carried with the fuel, and metered by the jet. Too small jet=too little lube=kaboom
What carb did you buy? A dellorto Sha 15/15 with a 1mm shim is the recommended replacement if you don't replace with a bigger intake manifold, and runs around a 70 jet. The stock gurtners are notoriously unreliable and the clone replacements come jetted wayyyy to lean.
I'm not trying to be mean, just letting you know that unlike a four stroke, no carb you can buy will work plug and play.