SDiK

I've just purchased the SDiK kit for a well mb01 and but unfortunately its not giving me the performance I wanted. I'm currently only getting around 2.5Jon .4g bb's with 2.2J on .2's. I've opened the SDiK to see if there's any reducer kit already installed and there appears to be a while plastic tube already in there, I can't seem to remove this and didn't want to force it out?

Has anyone else had any experience with the SDiK? I hoped to get around 3-3.5J with .48's but at this rate I can only use 4-.43g due to the low fps I'm getting. This image shows the white plastic cylinder I believe to be the volume reducer?

Thanks