here's the problem, taken from my review of the star g36, on this thread:
http://www.airsoftcanada.com/showthread.php?t=24622
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After testing the ROF and FPS, i took a high-cap and proceeded to shoot it to adjust the hop up and start adjusting the 3.5x scope. Before i could finish the one midcap (140rds), provided with the gun, it began acting up. The motor seemed like it was seizing up and something was binding and it didn't want to turn.
The first day and something is wrong with the gun... tsk tsk.
I've taken the gun completely apart and found that when the mechbox is not in the gun, this doesn't happen. But as soon as it's back inside the upper reciever, it begins acting like the battery is too weak and the motor can't push the spring.
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i'd also like to add that it seems to be a clone of TM's G36, so i'd like to see if anyone has any suggestions as to what they think might be the cause of error.