Originally Posted by pitvpr
The two holes on the firing engine must line up and must be facing the bottom of the marker body or the system will not get air and the marker will not fire. These holes match up with ports on the bottom of the marker body; operating air gets to the firing engine via these holes.
Here are the two holes with hex keys stuck in them. The third hole referred to in various posts is the hole underneath the back plate block. The hole on the back plate block serves no purpose other than assists in pulling the firing engine out of the marker body. This “third” hole is idiot proof, and cannot be misaligned; this is why most people refer to aligning the “three holes”. If you line up the two holes under the firing engine body, with the back plate hole, you are good to go!
My holes don't line up either. I'm pretty sure just the back two that you are talking about needs to be aligned. The ones that are already lined up as you described.