when a 2stroke is running the whole crank case is filled with airfuel mixture, if you got airleaks its impossible to get the tune right (i swear someone already posted this) so your motor is pulling in air without the fuel, worse case scenario and it will get worse, it leans out and melts down from the heat produced from such a lean condition
thats why you keep getting told to make sure the motor passes a leakdown test before bothering to chase down carb issues
there is a dude called Sparkys Garage on youtube go watch some of his banshee fixin' vids