Ok, i have noticed that alot of people have been having problems with their hp tanks on speeds and a4's. And i keep telling them the same thing. There is a mod you can perform, to make your mini reg able to use hp tanks and have no problems. It is a simple mod that takes about 10 minutes tops. I reccomend it to anyone who has a hp tank, who wants to get a lower velocity, or better performence.
Circlip Pliers, you can pick them up at your local hardware store. (Some companies call them Snap Ring Plyers)
Take off your mini reg, and take the circlip out. The circlip is a circular clip that you will see when you look down the mini reg.
Once the circlip is out of the mini reg, take a rag, or anything that will reduce scratches to the mini reg. And put it over the hole and hit it against a table until the internals come out.
When the internals are out, you will see the springs, (they are black.) take the springs off the metal piece. And arrange them so they go facing 2 down, 2 up, 2 down. (())((
If you are still confused about the position of the springs, look at this picture that DaveEllis donated.
You are done
Put the mini reg back together and your gun will be able to shoot under 300 fps with a hp tank.
Note: This mod has been approved by an angel tech. In fact, Bob from TAG originally posted how to do this at automags.org awhile back. This mod was done with a hp pmi tank. This mod works with 800 output tanks, i am not sure if it works with any lower.
This mod works on 03-04 Speeds, A4's and Fly A4's. I am not sure if this will work on the 05 Speed. It should work on the 05 Speed if you can get to the internals of the mini-reg.
Also, make sure you follow these instructions carefully, these are nice guns and you wouldnt want to mess them up.