well my blaster was running like a champ. but other day it started 2 rev up when i put the clutch in and sounding like it's sucking air. and if i try 2 top out in 6 gear i hear that sound like sand hitting inside pipe. i replaced gaskets on head and jug. made sure i was not leaking air on carb intake. i have had chain saw's 2 do this and i replaced carb and that fixed it. ps i did not let it make that sound long at all lol