Ver. 3 gearbox - how to check compression?
 

how do you check for leaks or bad compression on Ver. 3 gearbox?

my TM Aug only shoots 480-490fps (.2's) w/ SP160 which some have claimed to reach 600+ fps.

btw, stock Cylinder head
stock piston head
metal (non-bore up) nozzle
CA metal hop-up chamber w/ prometheus hop-up rubber.
CA 6.04 TB barrel

Need to open the mechbox, and take the spring/guide out. Then put a finger on the end of the nozzle, and use your other hand to move the piston back an forth in the cylinder and see how easy/hard it is to shove the piston in. Easy means low compression, very hard means good compression.

I found parts 1&2 very helpful:
"Questions / Symptoms:
- How to check compression? Is mine ok?
- I've poor / inconsistent FPS results"

http://forums.airsoftmechanics.com/i...hp?topic=908.0

thanks a lot!