ak drugonuv c02 advice

[croc1]

After some info bought a ak drugonov with co2 conversion of a member on here ( fell in half first time i cocked it) when it fires it fires like 3 quick burst like a zzz sort of thing ( fires one bb occosionaly 2) and the bb comes out low power wont even penetrate thin cardboard at 10 ft does anyone know what is causing this and how to fix, also when you pull the bolt to load each shot you get a hiss of air
thanks in advance