The TL;DR version of this message: -
If you swap reg collars, or change macroline elbows, ensure to re-install the Pressure Control Valve! - pictures below.
For those of short attention span, thank you for your patience......
For the rest of you, an explanation: -
Apologies to those who have already read this information elsewhere, but this subject matter relates to safe use of the Geo, and as such is obviously a cause for concern, and Planet would like to make sure that as many people as possible are aware of it.
Parts swapping is becoming a popular hobby amongst Geo owners, in order to create new colour combinations - no big issue there.
However, removing the swivel collar from the regulator - in order to swap collars - requires removal of your macroline elbow.
The macroline elbow contains a small but important safety feature in the form of a Purge Control Valve - a small plastic "Golf-Tee" shaped parts with a small hole drilled through it.
This parts sits in the end of your elbow like so: -
In normal use, the PCV will be pushed out of the elbow by the air entering the reg, and so it has no effect on air flow. When you purge the air from your marker, and the air tries to rush back out of the reg and through the elbow, the PCV will be pushed back in to the elbow, forcing the venting air to go through the small hole through the centre of the valve. As such, the air is forced to vent from the reg slowly.
This is important, as if the air in the front chamber of the bolt kit vents out before the air in the firing chamber - as it will, due to there being more air to vent from the firing chamber - the bolt will be pushed forwards, the remaining air in the firing chamber will be released, and the marker will fire. By slowing the release of the air, the PCV prevents the marker firing when you de-gas it. Of course, you should have a barrel sock on your barrel at this point, but better safe than sorry.
The upshot of this, and the whole point of this thread is as follows: -
If you are going to swap reg collars, be careful when removing the elbow, to prevent damaging the PCV. After swapping the collars, ensure that you re-install the PCV in to the elbow before screwing it back on.
Same goes if you need to change the elbow - install the PCV in your new elbow before screwing it back on.
***Failure to install the PCV in your HPR elbow can lead to the Geo firing when you de-gas it!***