start with a compression test. dude if it pulled dust in the carb it only takes a little to do alot.

 

to get a good idea of if the compression is good or not is to put your finger over the spark plug hole and crank over the engine, if your finger blows away then compression is good enough, this might not sound to precise but it gives you an idea if its good or bad, chances of the valves closing on you like i said before is a really good one, im only saying this because it has happened to me lots before, also make sure that your carb is on the manifold completly if in doubt undo the clamp and press in the carb also i would recommend using a regular hose clamp instead of the stock clamp, these seem to give better coverage