Got a new CTW a week ago. The riffle is chopping up bb's in the hopup unit when fired on full auto and losting power when in semi.

Help!

Well your first problem is that you got a CTW. Second might be that your cylinder unit is too far back. When it is too far towards the rear of the gun the nozzle might not slide far enough forward into the hop up; you will also lose a good amount of FPS. Shimming it with two or three shims usually does the trick. First thing I'd check.

Which company did you order the rifle?

I got the CTW from Hot SpotAirsoft and will check the shims.
Thanks

I called Hot Spot Airsoft and talked with tech. He thinks it the cylinder because i can hear a spring loose. he stated that the piston spring screw is losse are came out . so they have to lock tight it back.
Thanks guys for all your help and will keep you guys informed on results.